New stereo rendering implementation

interface/src/Application.cpp

@@ -1058,29 +1058,18 @@ void Application::paintGL() {
         // Using the latter will cause the camera to wobble with idle animations,
         // or with changes from the face tracker
         renderArgs._renderMode = RenderArgs::DEFAULT_RENDER_MODE;
-
+        _myCamera.setPosition(_myAvatar->getDefaultEyePosition());
-        if (!getActiveDisplayPlugin()->isHmd()) {
+        _myCamera.setRotation(_myAvatar->getOrientation());
-            _myCamera.setPosition(_myAvatar->getDefaultEyePosition());
-            _myCamera.setRotation(_myAvatar->getHead()->getCameraOrientation());
-        } else {
-            mat4 camMat = _myAvatar->getSensorToWorldMatrix() * _myAvatar->getHMDSensorMatrix();
-            _myCamera.setPosition(extractTranslation(camMat));
-            _myCamera.setRotation(glm::quat_cast(camMat));
-        }
     } else if (_myCamera.getMode() == CAMERA_MODE_THIRD_PERSON) {
-        if (isHMDMode()) {
+        _myCamera.setRotation(_myAvatar->getOrientation());
-            _myCamera.setRotation(_myAvatar->getWorldAlignedOrientation());
-        } else {
-            _myCamera.setRotation(_myAvatar->getHead()->getOrientation());
-        }
-        if (Menu::getInstance()->isOptionChecked(MenuOption::CenterPlayerInView)) {
-            _myCamera.setPosition(_myAvatar->getDefaultEyePosition() +
-                                  _myCamera.getRotation() * glm::vec3(0.0f, 0.0f, 1.0f) * _myAvatar->getBoomLength() * _myAvatar->getScale());
-        } else {
-            _myCamera.setPosition(_myAvatar->getDefaultEyePosition() +
-                                  _myAvatar->getOrientation() * glm::vec3(0.0f, 0.0f, 1.0f) * _myAvatar->getBoomLength() * _myAvatar->getScale());
-        }
 
+        // https://www.youtube.com/watch?v=pFriRcIwqNU
+        vec3 boomStick = glm::vec3(0.0f, 0.0f, 1.0f) * _myAvatar->getBoomLength() * _myAvatar->getScale();
+        quat boomRotation = _myAvatar->getOrientation();
+        if (!isHMDMode() && Menu::getInstance()->isOptionChecked(MenuOption::CenterPlayerInView)) {
+            boomRotation = _myCamera.getRotation();
+        } 
+        _myCamera.setPosition(_myAvatar->getDefaultEyePosition() + boomRotation * boomStick);
     } else if (_myCamera.getMode() == CAMERA_MODE_MIRROR) {
         _myCamera.setRotation(_myAvatar->getWorldAlignedOrientation() * glm::quat(glm::vec3(0.0f, PI + _rotateMirror, 0.0f)));
         _myCamera.setPosition(_myAvatar->getDefaultEyePosition() +
@@ -1089,7 +1078,6 @@ void Application::paintGL() {
                                glm::vec3(0.0f, 0.0f, -1.0f) * MIRROR_FULLSCREEN_DISTANCE * _scaleMirror);
         renderArgs._renderMode = RenderArgs::MIRROR_RENDER_MODE;
     }
-
     // Update camera position
     if (!isHMDMode()) {
         _myCamera.update(1.0f / _fps);
@@ -1105,57 +1093,37 @@ void Application::paintGL() {
         QSize size = DependencyManager::get<FramebufferCache>()->getFrameBufferSize();
         renderArgs._viewport = glm::ivec4(0, 0, size.width(), size.height());
 
-        {
+        doInBatch(&renderArgs, [&](gpu::Batch& batch) {
-            PROFILE_RANGE(__FUNCTION__ "/clear");
+            auto primaryFbo = DependencyManager::get<FramebufferCache>()->getPrimaryFramebuffer();
-            doInBatch(&renderArgs, [&](gpu::Batch& batch) {
+            batch.setFramebuffer(primaryFbo);
-                auto primaryFbo = DependencyManager::get<FramebufferCache>()->getPrimaryFramebuffer();
+            // clear the normal and specular buffers
-                batch.setFramebuffer(primaryFbo);
+            batch.clearFramebuffer(
-                // clear the normal and specular buffers
+                gpu::Framebuffer::BUFFER_COLOR0 |
-                batch.clearFramebuffer(
+                gpu::Framebuffer::BUFFER_COLOR1 |
-                    gpu::Framebuffer::BUFFER_COLOR0 |
+                gpu::Framebuffer::BUFFER_COLOR2 |
-                    gpu::Framebuffer::BUFFER_COLOR1 |
+                gpu::Framebuffer::BUFFER_DEPTH,
-                    gpu::Framebuffer::BUFFER_COLOR2 |
+                vec4(vec3(0), 1), 1.0, 0.0);
-                    gpu::Framebuffer::BUFFER_DEPTH,
+        });
-                    vec4(vec3(0), 1), 1.0, 0.0);
-            });
-        }
 
+        renderArgs._viewport = gpu::Vec4i(0, 0, size.width(), size.height());
         if (displayPlugin->isStereo()) {
-            PROFILE_RANGE(__FUNCTION__ "/stereoRender");
+            //_myCamera.setProjection(displayPlugin->getProjection(Mono, _myCamera.getProjection()));
-            QRect currentViewport(QPoint(0, 0), QSize(size.width() / 2, size.height()));
+            renderArgs._context->enableStereo(true);
-            glEnable(GL_SCISSOR_TEST);
+            mat4 eyeViews[2];
-            for_each_eye([&](Eye eye){
+            mat4 eyeProjections[2];
-                // Load the view frustum, used by meshes
+            auto baseProjection = renderArgs._viewFrustum->getProjection();
-                Camera eyeCamera;
+            // FIXME we don't need to set these every frame,
-                if (qApp->isHMDMode()) {
+            // only when the display plugin changes
-                    // Allow the displayPlugin to compose the final eye transform, based on the most up-to-date head motion.
+            for_each_eye([&](Eye eye) {
-                    eyeCamera.setTransform(displayPlugin->getModelview(eye, _myAvatar->getSensorToWorldMatrix()));
+                eyeViews[eye] = displayPlugin->getModelview(eye, mat4());
-                } else {
+                eyeProjections[eye] = displayPlugin->getProjection(eye, baseProjection);
-                    eyeCamera.setTransform(displayPlugin->getModelview(eye, _myCamera.getTransform()));
-                }
-                eyeCamera.setProjection(displayPlugin->getProjection(eye, _myCamera.getProjection()));
-                renderArgs._viewport = toGlm(currentViewport);
-                doInBatch(&renderArgs, [&](gpu::Batch& batch) {
-                    batch.setViewportTransform(renderArgs._viewport);
-                    batch.setStateScissorRect(renderArgs._viewport);
-                });
-                displaySide(&renderArgs, eyeCamera);
-            }, [&] {
-                currentViewport.moveLeft(currentViewport.width());
             });
-            glDisable(GL_SCISSOR_TEST);
+            renderArgs._context->setStereoProjections(eyeProjections);
-        } else {
+            renderArgs._context->setStereoViews(eyeViews);
-            PROFILE_RANGE(__FUNCTION__ "/monoRender");
-            renderArgs._viewport = gpu::Vec4i(0, 0, size.width(), size.height());
-            // Viewport is assigned to the size of the framebuffer
-            doInBatch(&renderArgs, [&](gpu::Batch& batch) {
-                batch.setViewportTransform(renderArgs._viewport);
-                batch.setStateScissorRect(renderArgs._viewport);
-            });
-            displaySide(&renderArgs, _myCamera);
         }
-
+        displaySide(&renderArgs, _myCamera);
-        doInBatch(&renderArgs, [](gpu::Batch& batch){
+        renderArgs._context->enableStereo(false);
+        doInBatch(&renderArgs, [](gpu::Batch& batch) {
             batch.setFramebuffer(nullptr);
         });
     }
@@ -4997,6 +4965,11 @@ mat4 Application::getHMDSensorPose() const {
     return mat4();
 }
 
+// FIXME there is a bug in the fullscreen setting, where leaving
+// fullscreen does not restore the window frame, making it difficult
+// or impossible to move or size the window.
+// Additionally, setting fullscreen isn't hiding the menu on windows
+// make it useless for stereoscopic modes.
 void Application::setFullscreen(const QScreen* target) {
     if (!_window->isFullScreen()) {
         _savedGeometry = _window->geometry();

interface/src/Stars.cpp

@@ -191,7 +191,7 @@ void Stars::render(RenderArgs* renderArgs, float alpha) {
     auto geometryCache = DependencyManager::get<GeometryCache>();
     auto textureCache = DependencyManager::get<TextureCache>();
 
-    gpu::Batch batch;
+    gpu::Batch& batch = *renderArgs->_batch;
     batch.setViewTransform(Transform());
     batch.setProjectionTransform(renderArgs->_viewFrustum->getProjection());
     batch.setModelTransform(Transform().setRotation(glm::inverse(renderArgs->_viewFrustum->getOrientation()) *
@@ -219,6 +219,4 @@ void Stars::render(RenderArgs* renderArgs, float alpha) {
     batch.setInputBuffer(VERTICES_SLOT, posView);
     batch.setInputBuffer(COLOR_SLOT, colView);
     batch.draw(gpu::Primitive::POINTS, STARFIELD_NUM_STARS);
-
-    renderArgs->_context->render(batch);
 }

interface/src/ui/ApplicationCompositor.cpp

@@ -211,7 +211,6 @@ void ApplicationCompositor::displayOverlayTexture(RenderArgs* renderArgs) {
     //Handle fading and deactivation/activation of UI
     gpu::Batch batch;
 
-    renderArgs->_context->syncCache();
     auto geometryCache = DependencyManager::get<GeometryCache>();
 
     geometryCache->useSimpleDrawPipeline(batch);
@@ -279,7 +278,6 @@ void ApplicationCompositor::displayOverlayTextureHmd(RenderArgs* renderArgs, int
     vec2 canvasSize = qApp->getCanvasSize();
     _textureAspectRatio = aspect(canvasSize);
 
-    renderArgs->_context->syncCache();
     auto geometryCache = DependencyManager::get<GeometryCache>();
 
     gpu::Batch batch;

interface/src/ui/ApplicationOverlay.cpp

@@ -92,7 +92,6 @@ void ApplicationOverlay::renderOverlay(RenderArgs* renderArgs) {
     renderOverlays(renderArgs); // renders Scripts Overlay and AudioScope
     renderStatsAndLogs(renderArgs);  // currently renders nothing
 
-    renderArgs->_context->syncCache();
     renderArgs->_context->render(batch);
 
     renderArgs->_batch = nullptr; // so future users of renderArgs don't try to use our batch

libraries/display-plugins/src/display-plugins/DisplayPlugin.cpp

@@ -28,7 +28,7 @@ DisplayPluginList getDisplayPlugins() {
 
         // Stereo modes
         // FIXME fix stereo display plugins
-        //new SideBySideStereoDisplayPlugin(),
+        new SideBySideStereoDisplayPlugin(),
         //new InterleavedStereoDisplayPlugin(),
 
         // HMDs

libraries/display-plugins/src/display-plugins/DisplayPlugin.h

@@ -107,6 +107,10 @@ public:
         static const glm::mat4 pose; return pose;
     }
 
+    virtual glm::vec3 getEyeOffset(Eye eye) const {
+        static const glm::vec3 offset; return offset;
+    }
+
     virtual glm::mat4 getHeadPose() const {
         static const glm::mat4 pose; return pose;
     }

libraries/display-plugins/src/display-plugins/oculus/OculusBaseDisplayPlugin.cpp

@@ -14,6 +14,9 @@
 
 using namespace Oculus;
 
+OculusBaseDisplayPlugin::OculusBaseDisplayPlugin() : _ipd(OVR_DEFAULT_IPD) {
+}
+
 void OculusBaseDisplayPlugin::activate() {
     glm::uvec2 eyeSizes[2];
     ovr_for_each_eye([&](ovrEyeType eye) {
@@ -27,9 +30,12 @@ void OculusBaseDisplayPlugin::activate() {
             ovrMatrix4f_Projection(erd.Fov, 0.001f, 10.0f, ovrProjection_RightHanded);
         _compositeEyeProjections[eye] = toGlm(ovrPerspectiveProjection);
 
-        _eyeOffsets[eye] = erd.HmdToEyeViewOffset;
+        // We handle the eye offsets slightly differently, using an _ipd in the base class
+        // _eyeOffsets[eye] = erd.HmdToEyeViewOffset;
+        _eyeOffsets[eye] = { 0, 0, 0 };
         eyeSizes[eye] = toGlm(ovrHmd_GetFovTextureSize(_hmd, eye, erd.Fov, 1.0f));
     });
+    _ipd = ovrHmd_GetFloat(_hmd, OVR_KEY_IPD, _ipd);
     _desiredFramebufferSize = uvec2(
         eyeSizes[0].x + eyeSizes[1].x,
         std::max(eyeSizes[0].y, eyeSizes[1].y));

libraries/display-plugins/src/display-plugins/oculus/OculusBaseDisplayPlugin.h

@@ -11,6 +11,7 @@
 
 class OculusBaseDisplayPlugin : public MainWindowOpenGLDisplayPlugin {
 public:
+    OculusBaseDisplayPlugin();
     // Stereo specific methods
     virtual bool isHmd() const override { return true; }
     virtual glm::mat4 getProjection(Eye eye, const glm::mat4& baseProjection) const override;
@@ -22,5 +23,6 @@ public:
     virtual void resetSensors() override;
     virtual glm::mat4 getEyePose(Eye eye) const override;
     virtual glm::mat4 getHeadPose() const override;
-
+protected:
+    float _ipd;
 };

libraries/display-plugins/src/display-plugins/stereo/SideBySideStereoDisplayPlugin.cpp

@@ -17,7 +17,7 @@
 
 #include <gpu/GLBackend.h>
 
-const QString SideBySideStereoDisplayPlugin::NAME("SBS Stereo Display");
+const QString SideBySideStereoDisplayPlugin::NAME("Debug Stereo Display");
 
 const QString & SideBySideStereoDisplayPlugin::getName() const {
     return NAME;

libraries/display-plugins/src/display-plugins/stereo/StereoDisplayPlugin.cpp

@@ -52,6 +52,16 @@ glm::mat4 StereoDisplayPlugin::getModelview(Eye eye, const glm::mat4& baseModelv
 
 void StereoDisplayPlugin::activate() {
     WindowOpenGLDisplayPlugin::activate();
-    CONTAINER->setFullscreen(qApp->primaryScreen());
+    // FIXME there is a bug in the fullscreen setting, see
+    // Application::setFullscreen
+    //CONTAINER->setFullscreen(qApp->primaryScreen());
     // FIXME Add menu items
 }
+
+glm::vec3 StereoDisplayPlugin::getEyeOffset(Eye eye) const {
+    glm::vec3 result(_ipd / 2.0f, 0, 0);
+    if (eye == Eye::Right) {
+        result *= -1.0f;
+    }
+    return result;
+}

libraries/display-plugins/src/display-plugins/stereo/StereoDisplayPlugin.h

@@ -20,5 +20,8 @@ public:
 
     virtual glm::mat4 getProjection(Eye eye, const glm::mat4& baseProjection) const override;
     virtual glm::mat4 getModelview(Eye eye, const glm::mat4& baseModelview) const override;
+    virtual glm::vec3 getEyeOffset(Eye eye) const override;
 
+protected:
+    float _ipd{ 0.064f };
 };

libraries/gpu/src/gpu/Batch.cpp

@@ -288,3 +288,18 @@ void Batch::resetStages() {
     ADD_COMMAND(resetStages);
 }
 
+void Batch::enableStereo(bool enable) {
+    _enableStereo = enable;
+}
+
+bool Batch::isStereoEnabled() const {
+    return _enableStereo;
+}
+
+void Batch::enableSkybox(bool enable) {
+    _enableSkybox = enable;
+}
+
+bool Batch::isSkyboxEnabled() const {
+    return _enableSkybox;
+}

libraries/gpu/src/gpu/Batch.h

@@ -26,7 +26,7 @@
         ProfileRange(const char *name);
         ~ProfileRange();
     };
-    #define PROFILE_RANGE(name) ProfileRange profileRangeThis(name);
+#define PROFILE_RANGE(name) ProfileRange profileRangeThis(name);
 #else
 #define PROFILE_RANGE(name)
 #endif
@@ -47,6 +47,19 @@ public:
     ~Batch();
 
     void clear();
+    
+    // Batches may need to override the context level stereo settings
+    // if they're performing framebuffer copy operations, like the 
+    // deferred lighting resolution mechanism
+    void enableStereo(bool enable = true);
+    bool isStereoEnabled() const;
+
+    // Stereo batches will pre-translate the view matrix, but this isn't 
+    // appropriate for skyboxes or other things intended to be drawn at 
+    // infinite distance, so provide a mechanism to render in stereo 
+    // without the pre-translation of the view.  
+    void enableSkybox(bool enable = true);
+    bool isSkyboxEnabled() const;
 
     // Drawcalls
     void draw(Primitive primitiveType, uint32 numVertices, uint32 startVertex = 0);
@@ -276,6 +289,9 @@ public:
     FramebufferCaches _framebuffers;
     QueryCaches _queries;
 
+    bool _enableStereo{ true };
+    bool _enableSkybox{ false };
+
 protected:
 };
 

libraries/gpu/src/gpu/Context.cpp

@@ -40,6 +40,18 @@ void Context::render(Batch& batch) {
     _backend->render(batch);
 }
 
+void Context::enableStereo(bool enable) {
+    _backend->enableStereo(enable);
+}
+
+void Context::setStereoProjections(const mat4 eyeProjections[2]) {
+    _backend->setStereoProjections(eyeProjections);
+}
+
+void Context::setStereoViews(const mat4 eyeViews[2]) {
+    _backend->setStereoViews(eyeViews);
+}
+
 void Context::syncCache() {
     PROFILE_RANGE(__FUNCTION__);
     _backend->syncCache();
@@ -49,3 +61,26 @@ void Context::downloadFramebuffer(const FramebufferPointer& srcFramebuffer, cons
     _backend->downloadFramebuffer(srcFramebuffer, region, destImage);
 }
 
+const Backend::TransformCamera& Backend::TransformCamera::recomputeDerived() const {
+    _projectionInverse = glm::inverse(_projection);
+    _viewInverse = glm::inverse(_view);
+
+    Mat4 viewUntranslated = _view;
+    viewUntranslated[3] = Vec4(0.0f, 0.0f, 0.0f, 1.0f);
+    _projectionViewUntranslated = _projection * viewUntranslated;
+    return *this;
+}
+
+Backend::TransformCamera Backend::TransformCamera::getEyeCamera(int eye, const StereoState& _stereo) const {
+    TransformCamera result = *this;
+    if (!_stereo._skybox) {
+        result._view = _stereo._eyeViews[eye] * result._view;
+    } else {
+        glm::mat4 skyboxView = _stereo._eyeViews[eye];
+        skyboxView[3] = vec4(0, 0, 0, 1);
+        result._view = skyboxView * result._view;
+    }
+    result._projection = _stereo._eyeProjections[eye];
+    result.recomputeDerived();
+    return result;
+}

libraries/gpu/src/gpu/Context.h

@@ -14,6 +14,8 @@
 #include <assert.h>
 #include <mutex>
 
+#include <GLMHelpers.h>
+
 #include "Batch.h"
 
 #include "Resource.h"
@@ -25,28 +27,58 @@ class QImage;
 
 namespace gpu {
 
+struct StereoState {
+    bool _enable{ false };
+    bool _skybox{ false };
+    // 0 for left eye, 1 for right eye
+    uint8_t _pass{ 0 };
+    mat4 _eyeViews[2];
+    mat4 _eyeProjections[2];
+};
+
 class Backend {
 public:
     virtual~ Backend() {};
 
     virtual void render(Batch& batch) = 0;
+    virtual void enableStereo(bool enable) {
+        _stereo._enable = enable;
+    }
+
+    void setStereoProjections(const mat4 eyeProjections[2]) {
+        for (int i = 0; i < 2; ++i) {
+            _stereo._eyeProjections[i] = eyeProjections[i];
+        }
+    }
+
+    void setStereoViews(const mat4 views[2]) {
+        for (int i = 0; i < 2; ++i) {
+            _stereo._eyeViews[i] = views[i];
+        }
+    }
+
     virtual void syncCache() = 0;
     virtual void downloadFramebuffer(const FramebufferPointer& srcFramebuffer, const Vec4i& region, QImage& destImage) = 0;
 
+    // UBO class... layout MUST match the layout in TransformCamera.slh
     class TransformObject {
     public:
         Mat4 _model;
         Mat4 _modelInverse;
     };
 
+    // UBO class... layout MUST match the layout in TransformCamera.slh
     class TransformCamera {
     public:
         Mat4 _view;
-        Mat4 _viewInverse;
+        mutable Mat4 _viewInverse;
-        Mat4 _projectionViewUntranslated;
+        mutable Mat4 _projectionViewUntranslated;
         Mat4 _projection;
-        Mat4 _projectionInverse;
+        mutable Mat4 _projectionInverse;
         Vec4 _viewport; // Public value is int but float in the shader to stay in floats for all the transform computations.
+
+        const Backend::TransformCamera& recomputeDerived() const;
+        TransformCamera getEyeCamera(int eye, const StereoState& stereo) const;
     };
 
     template< typename T >
@@ -113,7 +145,7 @@ public:
     }
 
 protected:
-
+    StereoState  _stereo;
 };
 
 class Context {
@@ -136,7 +168,9 @@ public:
     ~Context();
 
     void render(Batch& batch);
-
+    void enableStereo(bool enable = true);
+    void setStereoProjections(const mat4 eyeProjections[2]);
+    void setStereoViews(const mat4 eyeViews[2]);
     void syncCache();
 
     // Downloading the Framebuffer is a synchronous action that is not efficient.

libraries/gpu/src/gpu/Forward.h

@@ -0,0 +1,77 @@
+//
+//  Created by Bradley Austin Davis on 2015/08/15
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+#pragma once
+#ifndef hifi_gpu_Forward_h
+#define hifi_gpu_Forward_h
+
+namespace gpu {
+    class Batch;
+    class Backend;
+    class Context;
+    typedef std::shared_ptr<Context> ContextPointer;
+    class GPUObject;
+
+    typedef int Stamp;
+    typedef uint32_t uint32;
+    typedef int32_t int32;
+    typedef uint16_t uint16;
+    typedef int16_t int16;
+    typedef uint8_t uint8;
+    typedef int8_t int8;
+
+    typedef uint8 Byte;
+    typedef uint32 Offset;
+    typedef std::vector<Offset> Offsets;
+
+    typedef glm::mat4 Mat4;
+    typedef glm::mat3 Mat3;
+    typedef glm::vec4 Vec4;
+    typedef glm::ivec4 Vec4i;
+    typedef glm::vec3 Vec3;
+    typedef glm::vec2 Vec2;
+    typedef glm::ivec2 Vec2i;
+    typedef glm::uvec2 Vec2u;
+
+    class Element;
+    typedef Element Format;
+    class Swapchain;
+    typedef std::shared_ptr<Swapchain> SwapchainPointer;
+    class Framebuffer;
+    typedef std::shared_ptr<Framebuffer> FramebufferPointer;
+    class Pipeline;
+    typedef std::shared_ptr<Pipeline> PipelinePointer;
+    typedef std::vector<PipelinePointer> Pipelines;
+    class Query;
+    typedef std::shared_ptr<Query> QueryPointer;
+    typedef std::vector<QueryPointer> Queries;
+    class Resource;
+    class Buffer;
+    typedef std::shared_ptr<Buffer> BufferPointer;
+    typedef std::vector<BufferPointer> Buffers;
+    class BufferView;
+    class Shader;
+    typedef Shader::Pointer ShaderPointer;
+    typedef std::vector<ShaderPointer> Shaders;
+    class State;
+    typedef std::shared_ptr<State> StatePointer;
+    typedef std::vector<StatePointer> States;
+    class Stream;
+    class BufferStream;
+    typedef std::shared_ptr<BufferStream> BufferStreamPointer;
+    class Texture;
+    class SphericalHarmonics;
+    typedef std::shared_ptr<SphericalHarmonics> SHPointer;
+    class Sampler;
+    class Texture;
+    typedef std::shared_ptr<Texture> TexturePointer;
+    typedef std::vector<TexturePointer> Textures;
+    class TextureView;
+    typedef std::vector<TextureView> TextureViews;
+}
+
+#endif

libraries/gpu/src/gpu/GLBackend.cpp

@@ -127,39 +127,29 @@ void GLBackend::renderPassTransfer(Batch& batch) {
     const Batch::Commands::value_type* command = batch.getCommands().data();
     const Batch::CommandOffsets::value_type* offset = batch.getCommandOffsets().data();
 
-    _transform._cameraTransforms.resize(0);
+    // Reset the transform buffers
-    _transform._cameraTransforms.push_back(TransformCamera());
+    _transform._cameras.resize(0);
     _transform._cameraOffsets.clear();
-    _transform._cameraOffsets.push_back(TransformStageState::Pair(0, 0));
+    _transform._objects.resize(0);
-
-    _transform._objectTransforms.push_back(TransformObject());
-    _transform._objectOffsets.push_back(TransformStageState::Pair(0, 0));
     _transform._objectOffsets.clear();
-    _transform._objectTransforms.resize(0);
-   
-    _commandIndex = 0;
-    preUpdateTransform();
 
-    int drawCount = 0;
     for (_commandIndex = 0; _commandIndex < numCommands; ++_commandIndex) {
         switch (*command) {
             case Batch::COMMAND_draw:
             case Batch::COMMAND_drawIndexed:
             case Batch::COMMAND_drawInstanced:
             case Batch::COMMAND_drawIndexedInstanced:
-                preUpdateTransform();
+                _transform.preUpdate(_commandIndex, _stereo);
-                ++drawCount;
                 break;
 
             case Batch::COMMAND_setModelTransform:
             case Batch::COMMAND_setViewportTransform:
             case Batch::COMMAND_setViewTransform:
-            case Batch::COMMAND_setProjectionTransform:
+            case Batch::COMMAND_setProjectionTransform: {
-            {
                 CommandCall call = _commandCalls[(*command)];
                 (this->*(call))(batch, *offset);
+                break;
             }
-            break;
 
             default:
                 break;
@@ -167,44 +157,31 @@ void GLBackend::renderPassTransfer(Batch& batch) {
         command++;
         offset++;
     }
-
+    _transform.transfer();
-    
-    static QByteArray bufferData;
-    glBindBuffer(GL_UNIFORM_BUFFER, _transform._transformCameraBuffer);
-    bufferData.resize(_transform._cameraUboSize * _transform._cameraTransforms.size());
-    for (size_t i = 0; i < _transform._cameraTransforms.size(); ++i) {
-        memcpy(bufferData.data() + (_transform._cameraUboSize * i), &_transform._cameraTransforms[i], sizeof(TransformCamera));
-    }
-    glBufferData(GL_UNIFORM_BUFFER, bufferData.size(), bufferData.data(), GL_DYNAMIC_DRAW);
-    glBindBuffer(GL_UNIFORM_BUFFER, _transform._transformObjectBuffer);
-    bufferData.resize(_transform._objectUboSize * _transform._objectTransforms.size());
-    for (size_t i = 0; i < _transform._objectTransforms.size(); ++i) {
-        memcpy(bufferData.data() + (_transform._objectUboSize * i), &_transform._objectTransforms[i], sizeof(TransformObject));
-    }
-    glBufferData(GL_UNIFORM_BUFFER, bufferData.size(), bufferData.data(), GL_DYNAMIC_DRAW);
-    glBindBuffer(GL_UNIFORM_BUFFER, 0);
-    CHECK_GL_ERROR();
 }
 
 void GLBackend::renderPassDraw(Batch& batch) {
+    _transform._objectsItr = _transform._objectOffsets.begin();
+    _transform._camerasItr = _transform._cameraOffsets.begin();
     const size_t numCommands = batch.getCommands().size();
     const Batch::Commands::value_type* command = batch.getCommands().data();
     const Batch::CommandOffsets::value_type* offset = batch.getCommandOffsets().data();
     for (_commandIndex = 0; _commandIndex < numCommands; ++_commandIndex) {
         switch (*command) {
             // Ignore these commands on this pass, taken care of in the transfer pass
+            // Note we allow COMMAND_setViewportTransform to occur in both passes
+            // as it both updates the transform object (and thus the uniforms in the 
+            // UBO) as well as executes the actual viewport call
             case Batch::COMMAND_setModelTransform:
-            case Batch::COMMAND_setViewportTransform:
             case Batch::COMMAND_setViewTransform:
             case Batch::COMMAND_setProjectionTransform:
                 break;
 
-            default:
+            default: {
-            {
                 CommandCall call = _commandCalls[(*command)];
                 (this->*(call))(batch, *offset);
+                break;
             }
-            break;
         }
 
         command++;
@@ -213,8 +190,33 @@ void GLBackend::renderPassDraw(Batch& batch) {
 }
 
 void GLBackend::render(Batch& batch) {
-    renderPassTransfer(batch);
+    _stereo._skybox = batch.isSkyboxEnabled();
-    renderPassDraw(batch);
+    // Allow the batch to override the rendering stereo settings
+    // for things like full framebuffer copy operations (deferred lighting passes)
+    bool savedStereo = _stereo._enable;
+    if (!batch.isStereoEnabled()) {
+        _stereo._enable = false;
+    }
+
+    {
+        PROFILE_RANGE("Transfer");
+        renderPassTransfer(batch);
+    }
+
+    {
+        PROFILE_RANGE(_stereo._enable ? "LeftRender" : "Render");
+        renderPassDraw(batch);
+    }
+
+    if (_stereo._enable) {
+        PROFILE_RANGE("RightRender");
+        _stereo._pass = 1;
+        renderPassDraw(batch);
+        _stereo._pass = 0;
+    }
+
+    // Restore the saved stereo state for the next batch
+    _stereo._enable = savedStereo;
 }
 
 bool GLBackend::checkGLError(const char* name) {

libraries/gpu/src/gpu/GLBackend.h

@@ -310,19 +310,22 @@ protected:
     void killTransform();
     // Synchronize the state cache of this Backend with the actual real state of the GL Context
     void syncTransformStateCache();
-    void updateTransform();
+    void updateTransform() const;
-    void preUpdateTransform();
     void resetTransformStage();
-    struct TransformStageState {
-        TransformObject _transformObject;
-        TransformCamera _transformCamera;
 
-        std::vector<TransformObject> _objectTransforms;
+    struct TransformStageState {
-        std::vector<TransformCamera> _cameraTransforms;
+        using TransformObjects = std::vector<TransformObject>;
+        using TransformCameras = std::vector<TransformCamera>;
+
+        TransformObject _object;
+        TransformCamera _camera;
+        TransformObjects _objects;
+        TransformCameras _cameras;
+
         size_t _cameraUboSize{ 0 };
         size_t _objectUboSize{ 0 };
-        GLuint _transformObjectBuffer{ 0 };
+        GLuint _objectBuffer{ 0 };
-        GLuint _transformCameraBuffer{ 0 };
+        GLuint _cameraBuffer{ 0 };
         Transform _model;
         Transform _view;
         Mat4 _projection;
@@ -336,6 +339,12 @@ protected:
         using List = std::list<Pair>;
         List _cameraOffsets;
         List _objectOffsets;
+        mutable List::const_iterator _objectsItr;
+        mutable List::const_iterator _camerasItr;
+
+        void preUpdate(size_t commandIndex, const StereoState& stereo);
+        void update(size_t commandIndex, const StereoState& stereo) const;
+        void transfer() const;
     } _transform;
 
     int32_t _uboAlignment{ 0 };

libraries/gpu/src/gpu/GLBackendOutput.cpp

@@ -198,6 +198,9 @@ void GLBackend::do_setFramebuffer(Batch& batch, uint32 paramOffset) {
 }
 
 void GLBackend::do_clearFramebuffer(Batch& batch, uint32 paramOffset) {
+    if (_stereo._enable && !_pipeline._stateCache.scissorEnable) {
+        qWarning("Clear without scissor in stereo mode");
+    }
 
     uint32 masks = batch._params[paramOffset + 7]._uint;
     Vec4 color;

libraries/gpu/src/gpu/GLBackendState.cpp

@@ -768,6 +768,12 @@ void GLBackend::do_setStateScissorRect(Batch& batch, uint32 paramOffset) {
     Vec4i rect;
     memcpy(&rect, batch.editData(batch._params[paramOffset]._uint), sizeof(Vec4i));
 
+    if (_stereo._enable) {
+        rect.z /= 2;
+        if (_stereo._pass) {
+            rect.x += rect.z;
+        }
+    }
     glScissor(rect.x, rect.y, rect.z, rect.w);
     (void) CHECK_GL_ERROR();
 }

libraries/gpu/src/gpu/GLBackendTransform.cpp

@@ -33,16 +33,26 @@ void GLBackend::do_setProjectionTransform(Batch& batch, uint32 paramOffset) {
 void GLBackend::do_setViewportTransform(Batch& batch, uint32 paramOffset) {
     memcpy(&_transform._viewport, batch.editData(batch._params[paramOffset]._uint), sizeof(Vec4i));
 
+    ivec4& vp = _transform._viewport;
+
     // Where we assign the GL viewport
-    glViewport(_transform._viewport.x, _transform._viewport.y, _transform._viewport.z, _transform._viewport.w);
+    if (_stereo._enable) {
+        vp.z /= 2;
+        if (_stereo._pass) {
+            vp.x += vp.z;
+        }
+        int i = 0;
+    } 
+
+    glViewport(vp.x, vp.y, vp.z, vp.w);
 
     // The Viewport is tagged invalid because the CameraTransformUBO is not up to date and willl need update on next drawcall
     _transform._invalidViewport = true;
 }
 
 void GLBackend::initTransform() {
-    glGenBuffers(1, &_transform._transformObjectBuffer);
+    glGenBuffers(1, &_transform._objectBuffer);
-    glGenBuffers(1, &_transform._transformCameraBuffer);
+    glGenBuffers(1, &_transform._cameraBuffer);
     size_t cameraSize = sizeof(TransformCamera);
     while (_transform._cameraUboSize < cameraSize) {
         _transform._cameraUboSize += _uboAlignment;
@@ -54,8 +64,8 @@ void GLBackend::initTransform() {
 }
 
 void GLBackend::killTransform() {
-    glDeleteBuffers(1, &_transform._transformObjectBuffer);
+    glDeleteBuffers(1, &_transform._objectBuffer);
-    glDeleteBuffers(1, &_transform._transformCameraBuffer);
+    glDeleteBuffers(1, &_transform._cameraBuffer);
 }
 
 void GLBackend::syncTransformStateCache() {
@@ -72,73 +82,98 @@ void GLBackend::syncTransformStateCache() {
     _transform._model.setIdentity();
 }
 
-void GLBackend::preUpdateTransform() {
+void GLBackend::TransformStageState::preUpdate(size_t commandIndex, const StereoState& stereo) {
     // Check all the dirty flags and update the state accordingly
-    if (_transform._invalidViewport) {
+    if (_invalidViewport) {
-        _transform._transformCamera._viewport = glm::vec4(_transform._viewport);
+        _camera._viewport = glm::vec4(_viewport);
     }
 
-    if (_transform._invalidProj) {
+    if (_invalidProj) {
-        _transform._transformCamera._projection = _transform._projection;
+        _camera._projection = _projection;
-        _transform._transformCamera._projectionInverse = glm::inverse(_transform._projection);
     }
 
-    if (_transform._invalidView) {
+    if (_invalidView) {
-        _transform._view.getInverseMatrix(_transform._transformCamera._view);
+        _view.getInverseMatrix(_camera._view);
-        _transform._view.getMatrix(_transform._transformCamera._viewInverse);
     }
 
-    if (_transform._invalidModel) {
+    if (_invalidModel) {
-        _transform._model.getMatrix(_transform._transformObject._model);
+        _model.getMatrix(_object._model);
-        _transform._model.getInverseMatrix(_transform._transformObject._modelInverse);
+        _model.getInverseMatrix(_object._modelInverse);
     }
 
-    if (_transform._invalidView || _transform._invalidProj) {
+    if (_invalidView || _invalidProj || _invalidViewport) {
-        Mat4 viewUntranslated = _transform._transformCamera._view;
+        size_t offset = _cameraUboSize * _cameras.size();
-        viewUntranslated[3] = Vec4(0.0f, 0.0f, 0.0f, 1.0f);
+        if (stereo._enable) {
-        _transform._transformCamera._projectionViewUntranslated = _transform._transformCamera._projection * viewUntranslated;
+            _cameraOffsets.push_back(TransformStageState::Pair(commandIndex, offset));
+            for (int i = 0; i < 2; ++i) {
+                _cameras.push_back(_camera.getEyeCamera(i, stereo));
+            }
+        } else {
+            _cameraOffsets.push_back(TransformStageState::Pair(commandIndex, offset));
+            _cameras.push_back(_camera.recomputeDerived());
+        }
     }
 
-    if (_transform._invalidView || _transform._invalidProj || _transform._invalidViewport) {
+    if (_invalidModel) {
-        _transform._cameraOffsets.push_back(TransformStageState::Pair(_commandIndex, _transform._cameraUboSize * _transform._cameraTransforms.size()));
+        size_t offset = _objectUboSize * _objects.size();
-        _transform._cameraTransforms.push_back(_transform._transformCamera);
+        _objectOffsets.push_back(TransformStageState::Pair(commandIndex, offset));
-    }
+        _objects.push_back(_object);
-
-    if (_transform._invalidModel) {
-        _transform._objectOffsets.push_back(TransformStageState::Pair(_commandIndex, _transform._objectUboSize * _transform._objectTransforms.size()));
-        _transform._objectTransforms.push_back(_transform._transformObject);
     }
 
     // Flags are clean
-    _transform._invalidView = _transform._invalidProj = _transform._invalidModel = _transform._invalidViewport = false;
+    _invalidView = _invalidProj = _invalidModel = _invalidViewport = false;
 }
 
-void GLBackend::updateTransform() {
+void GLBackend::TransformStageState::transfer() const {
+    static QByteArray bufferData;
+    glBindBuffer(GL_UNIFORM_BUFFER, _cameraBuffer);
+    bufferData.resize(_cameraUboSize * _cameras.size());
+    for (size_t i = 0; i < _cameras.size(); ++i) {
+        memcpy(bufferData.data() + (_cameraUboSize * i), &_cameras[i], sizeof(TransformCamera));
+    }
+    glBufferData(GL_UNIFORM_BUFFER, bufferData.size(), bufferData.data(), GL_DYNAMIC_DRAW);
+    glBindBuffer(GL_UNIFORM_BUFFER, _objectBuffer);
+    bufferData.resize(_objectUboSize * _objects.size());
+    for (size_t i = 0; i < _objects.size(); ++i) {
+        memcpy(bufferData.data() + (_objectUboSize * i), &_objects[i], sizeof(TransformObject));
+    }
+    glBufferData(GL_UNIFORM_BUFFER, bufferData.size(), bufferData.data(), GL_DYNAMIC_DRAW);
+    glBindBuffer(GL_UNIFORM_BUFFER, 0);
+    CHECK_GL_ERROR();
+}
+
+void GLBackend::TransformStageState::update(size_t commandIndex, const StereoState& stereo) const {
     int offset = -1;
-    while (!_transform._objectOffsets.empty() && _commandIndex >= _transform._objectOffsets.front().first) {
+    while ((_objectsItr != _objectOffsets.end()) && (commandIndex >= (*_objectsItr).first)) {
-        offset = _transform._objectOffsets.front().second;
+        offset = (*_objectsItr).second;
-        _transform._objectOffsets.pop_front();
+        ++_objectsItr;
     }
     if (offset >= 0) {
-        glBindBufferRange(GL_UNIFORM_BUFFER, TRANSFORM_OBJECT_SLOT, 
+        glBindBufferRange(GL_UNIFORM_BUFFER, TRANSFORM_OBJECT_SLOT,
-            _transform._transformObjectBuffer,
+            _objectBuffer, offset, sizeof(Backend::TransformObject));
-            offset, sizeof(Backend::TransformObject));
     }
 
     offset = -1;
-    while (!_transform._cameraOffsets.empty() && _commandIndex >= _transform._cameraOffsets.front().first) {
+    while ((_camerasItr != _cameraOffsets.end()) && (commandIndex >= (*_camerasItr).first)) {
-        offset = _transform._cameraOffsets.front().second;
+        offset = (*_camerasItr).second;
-        _transform._cameraOffsets.pop_front();
+        ++_camerasItr;
     }
     if (offset >= 0) {
-        glBindBufferRange(GL_UNIFORM_BUFFER, TRANSFORM_CAMERA_SLOT, 
+        // We include both camera offsets for stereo
-            _transform._transformCameraBuffer,
+        if (stereo._enable && stereo._pass) {
-            offset, sizeof(Backend::TransformCamera));
+            offset += _cameraUboSize;
+        }
+        glBindBufferRange(GL_UNIFORM_BUFFER, TRANSFORM_CAMERA_SLOT,
+            _cameraBuffer, offset, sizeof(Backend::TransformCamera));
     }
 
     (void)CHECK_GL_ERROR();
 }
 
+void GLBackend::updateTransform() const {
+    _transform.update(_commandIndex, _stereo);
+}
+
 void GLBackend::resetTransformStage() {
     
 }

libraries/input-plugins/src/input-plugins/ViveControllerManager.cpp

@@ -189,7 +189,6 @@ void ViveControllerManager::updateRendering(RenderArgs* args, render::ScenePoint
             renderHand(rightHand, batch, RIGHT_HAND);
         }
 
-        args->_context->syncCache();
         args->_context->render(batch);
     }
 }

libraries/render-utils/src/AmbientOcclusionEffect.cpp

@@ -246,6 +246,5 @@ void AmbientOcclusion::run(const render::SceneContextPointer& sceneContext, cons
     DependencyManager::get<GeometryCache>()->renderQuad(batch, bottomLeft, topRight, texCoordTopLeft, texCoordBottomRight, color);
     
     // Ready to render
-    args->_context->syncCache();
     args->_context->render((batch));
 }

libraries/render-utils/src/DeferredLightingEffect.cpp

@@ -225,6 +225,7 @@ void DeferredLightingEffect::addSpotLight(const glm::vec3& position, float radiu
 
 void DeferredLightingEffect::prepare(RenderArgs* args) {
     gpu::Batch batch;
+    batch.enableStereo(false);
 
     batch.setStateScissorRect(args->_viewport);
 
@@ -244,6 +245,9 @@ gpu::FramebufferPointer _copyFBO;
 void DeferredLightingEffect::render(RenderArgs* args) {
     gpu::Batch batch;
 
+    // Framebuffer copy operations cannot function as multipass stereo operations.  
+    batch.enableStereo(false);
+
     // perform deferred lighting, rendering to free fbo
     auto framebufferCache = DependencyManager::get<FramebufferCache>();
     
@@ -555,6 +559,7 @@ void DeferredLightingEffect::render(RenderArgs* args) {
 
 void DeferredLightingEffect::copyBack(RenderArgs* args) {
     gpu::Batch batch;
+    batch.enableStereo(false);
     auto framebufferCache = DependencyManager::get<FramebufferCache>();
     QSize framebufferSize = framebufferCache->getFrameBufferSize();
 

libraries/render-utils/src/RenderDeferredTask.cpp

@@ -35,6 +35,7 @@ void SetupDeferred::run(const SceneContextPointer& sceneContext, const RenderCon
     auto primaryFbo = DependencyManager::get<FramebufferCache>()->getPrimaryFramebufferDepthColor();
 
     gpu::Batch batch;
+    batch.enableStereo(false);
     batch.setFramebuffer(nullptr);
     batch.setFramebuffer(primaryFbo);
  
@@ -159,6 +160,8 @@ void DrawOpaqueDeferred::run(const SceneContextPointer& sceneContext, const Rend
 
     RenderArgs* args = renderContext->args;
     gpu::Batch batch;
+    batch.setViewportTransform(args->_viewport);
+    batch.setStateScissorRect(args->_viewport);
     args->_batch = &batch;
 
     renderContext->_numDrawnOpaqueItems = inItems.size();
@@ -188,6 +191,8 @@ void DrawTransparentDeferred::run(const SceneContextPointer& sceneContext, const
 
     RenderArgs* args = renderContext->args;
     gpu::Batch batch;
+    batch.setViewportTransform(args->_viewport);
+    batch.setStateScissorRect(args->_viewport);
     args->_batch = &batch;
     
     renderContext->_numDrawnTransparentItems = inItems.size();
@@ -247,30 +252,42 @@ void DrawOverlay3D::run(const SceneContextPointer& sceneContext, const RenderCon
     renderContext->_numFeedOverlay3DItems = inItems.size();
     renderContext->_numDrawnOverlay3DItems = inItems.size();
 
-    RenderArgs* args = renderContext->args;
-    gpu::Batch batch;
-    args->_batch = &batch;
-    args->_whiteTexture = DependencyManager::get<TextureCache>()->getWhiteTexture();
-
-    glm::mat4 projMat;
-    Transform viewMat;
-    args->_viewFrustum->evalProjectionMatrix(projMat);
-    args->_viewFrustum->evalViewTransform(viewMat);
-
-    batch.setProjectionTransform(projMat);
-    batch.setViewTransform(viewMat);
-    batch.setViewportTransform(args->_viewport);
-    batch.setStateScissorRect(args->_viewport);
-
-    batch.setPipeline(getOpaquePipeline());
-    batch.setResourceTexture(0, args->_whiteTexture);
-
     if (!inItems.empty()) {
-        batch.clearFramebuffer(gpu::Framebuffer::BUFFER_DEPTH, glm::vec4(), 1.f, 0, true);
+        RenderArgs* args = renderContext->args;
-        renderItems(sceneContext, renderContext, inItems, renderContext->_maxDrawnOverlay3DItems);
-    }
 
-    args->_context->render((*args->_batch));
+        // Clear the framebuffer without stereo
-    args->_batch = nullptr;
+        // Needs to be distinct from the other batch because using the clear call 
-    args->_whiteTexture.reset();
+        // while stereo is enabled triggers a warning
+        {
+            gpu::Batch batch;
+            batch.enableStereo(false);
+            batch.clearFramebuffer(gpu::Framebuffer::BUFFER_DEPTH, glm::vec4(), 1.f, 0, true);
+            args->_context->render(batch);
+        }
+
+        // Render the items
+        {
+            gpu::Batch batch;
+            args->_batch = &batch;
+            args->_whiteTexture = DependencyManager::get<TextureCache>()->getWhiteTexture();
+
+            glm::mat4 projMat;
+            Transform viewMat;
+            args->_viewFrustum->evalProjectionMatrix(projMat);
+            args->_viewFrustum->evalViewTransform(viewMat);
+
+            batch.setProjectionTransform(projMat);
+            batch.setViewTransform(viewMat);
+            batch.setViewportTransform(args->_viewport);
+            batch.setStateScissorRect(args->_viewport);
+
+            batch.setPipeline(getOpaquePipeline());
+            batch.setResourceTexture(0, args->_whiteTexture);
+            renderItems(sceneContext, renderContext, inItems, renderContext->_maxDrawnOverlay3DItems);
+
+            args->_context->render((*args->_batch));
+            args->_batch = nullptr;
+            args->_whiteTexture.reset();
+        }
+    }
 }

libraries/render/src/render/DrawStatus.cpp

@@ -161,8 +161,5 @@ void DrawStatus::run(const SceneContextPointer& sceneContext, const RenderContex
         batch.draw(gpu::TRIANGLES, 24, 0);
     }
 
-    // Before rendering the batch make sure we re in sync with gl state
+    args->_context->render(batch);
-    args->_context->syncCache();
-    renderContext->args->_context->syncCache();
-    args->_context->render((batch));
 }

libraries/render/src/render/DrawTask.cpp

@@ -258,6 +258,9 @@ void DrawBackground::run(const SceneContextPointer& sceneContext, const RenderCo
     }
     RenderArgs* args = renderContext->args;
     gpu::Batch batch;
+    batch.enableSkybox(true);
+    batch.setViewportTransform(args->_viewport);
+    batch.setStateScissorRect(args->_viewport);
     args->_batch = &batch;
 
     glm::mat4 projMat;
@@ -271,9 +274,6 @@ void DrawBackground::run(const SceneContextPointer& sceneContext, const RenderCo
     renderItems(sceneContext, renderContext, inItems);
     args->_context->render((*args->_batch));
     args->_batch = nullptr;
-
-    // Force the context sync
-    args->_context->syncCache();
 }
 
 void ItemMaterialBucketMap::insert(const ItemID& id, const model::MaterialKey& key) {