Circle drawn with camera orientation as its normal for lookatIndicator.

interface/src/Application.cpp

@@ -1676,6 +1676,8 @@ void Application::initMenu() {
     _renderFrameTimerOn->setChecked(false);
     (_renderLookatOn = renderMenu->addAction("Lookat Vectors"))->setCheckable(true);
     _renderLookatOn->setChecked(false);
+    (_renderLookatIndicatorOn = renderMenu->addAction("Lookat Indicator"))->setCheckable(true);
+    _renderLookatIndicatorOn->setChecked(true);
     (_manualFirstPerson = renderMenu->addAction(
         "First Person", this, SLOT(setRenderFirstPerson(bool)), Qt::Key_P))->setCheckable(true);
     (_manualThirdPerson = renderMenu->addAction(
@@ -1887,7 +1889,7 @@ bool Application::isLookingAtOtherAvatar(glm::vec3& mouseRayOrigin, glm::vec3& m
             glm::vec3 headPosition = avatar->getHead().getPosition();
             if (rayIntersectsSphere(mouseRayOrigin, mouseRayDirection, headPosition, HEAD_SPHERE_RADIUS)) {
                 eyePosition = avatar->getHead().getEyeLevelPosition();
-                renderLookatIndicator(headPosition);
+                _lookatOtherPosition = headPosition;
                 return true;
             }
         }
@@ -1895,24 +1897,19 @@ bool Application::isLookingAtOtherAvatar(glm::vec3& mouseRayOrigin, glm::vec3& m
     return false;
 }
 
-void Application::renderLookatIndicator(glm::vec3& pointOfInterest) {
-    // Render a circle between me and the avatar in question.
+void Application::renderLookatIndicator(glm::vec3 pointOfInterest, Camera& whichCamera) {
 
-    // I need a vector that is perpendicular to the vector from my camera position to the head position.
-    // Start by locating point on vector that will be the center of the circle.
-    glm::vec3 direction = glm::normalize(pointOfInterest - _myCamera.getPosition());
+    glm::vec3 direction = glm::normalize(pointOfInterest - whichCamera.getPosition());
     const float DISTANCE_FROM_HEAD_SPHERE = 0.1f;
     glm::vec3 indicatorOrigin = pointOfInterest - DISTANCE_FROM_HEAD_SPHERE * direction;
-    // Then find a perpendicular vector/point
-    // const float ARB_X = 1.0f;
-    // const float ARB_Y = 1.0f;
 
-    // float z = - (direction.x * ARB_X + direction.y * ARB_Y) / direction.z;
-    // glm::vec3 perpendicular(ARB_X, ARB_Y, z);
-    // perpendicular = glm::normalize(perpendicular);
-    // glm::vec3 startingVertex = indicatorOrigin + perpendicular;
-    renderCircle(indicatorOrigin, 0.1, direction, 30);
+    // glm::vec3 haloOrigin(pointOfInterest.x, pointOfInterest.y + DISTANCE_FROM_HEAD_SPHERE, pointOfInterest.z);
 
+    glColor3f(1.0f, 0.0f, 0.0f);
+    // renderCircle(haloOrigin, 0.1f, glm::vec3(0.0f, 1.0f, 0.0f), 30);
+    // glm::vec3 normal;
+    // _viewFrustum.computeNormalToNearClipPlane(normal);
+    renderCircle(indicatorOrigin, 0.1f, _viewFrustum.getDirection(), 30);
 }
 
 void Application::update(float deltaTime) {
@@ -2605,6 +2602,10 @@ void Application::displaySide(Camera& whichCamera) {
         } 
         _myAvatar.render(_lookingInMirror->isChecked(), _renderAvatarBalls->isChecked());
         _myAvatar.setDisplayingLookatVectors(_renderLookatOn->isChecked());
+
+        if (_renderLookatIndicatorOn->isChecked() && _isLookingAtOtherAvatar) {
+            renderLookatIndicator(_lookatOtherPosition, whichCamera);
+        }
     }
 
     if (TESTING_PARTICLE_SYSTEM) {

interface/src/Application.h

@@ -195,6 +195,7 @@ private:
     
     void update(float deltaTime);
     bool isLookingAtOtherAvatar(glm::vec3& mouseRayOrigin, glm::vec3& mouseRayDirection, glm::vec3& eyePosition);
+    void renderLookatIndicator(glm::vec3 pointOfInterest, Camera& whichCamera);
     void updateAvatar(float deltaTime);
     void loadViewFrustum(Camera& camera, ViewFrustum& viewFrustum);
     
@@ -250,6 +251,7 @@ private:
     QAction* _renderStatsOn;         // Whether to show onscreen text overlay with stats
     QAction* _renderFrameTimerOn;    // Whether to show onscreen text overlay with stats
     QAction* _renderLookatOn;        // Whether to show lookat vectors from avatar eyes if looking at something
+    QAction* _renderLookatIndicatorOn;
     QAction* _manualFirstPerson;     // Whether to force first-person mode
     QAction* _manualThirdPerson;     // Whether to force third-person mode
     QAction* _logOn;                 // Whether to show on-screen log
@@ -365,6 +367,7 @@ private:
     bool _justEditedVoxel;        // set when we've just added/deleted/colored a voxel
 
     bool _isLookingAtOtherAvatar;
+    glm::vec3 _lookatOtherPosition;
     
     bool _paintOn;                // Whether to paint voxels as you fly around
     unsigned char _dominantColor; // The dominant color of the voxel we're painting

libraries/voxels/src/ViewFrustum.cpp

@@ -364,7 +364,10 @@ bool ViewFrustum::matches(const ViewFrustum& compareTo, bool debug) const {
     return result;
 }
 
-
+void ViewFrustum::computeNormalToNearClipPlane(glm::vec3& normal) const {
+    Plane nearClipPlane(_nearTopLeft, _nearTopRight, _nearBottomLeft);
+    normal = nearClipPlane.getNormal();
+}
 
 void ViewFrustum::computePickRay(float x, float y, glm::vec3& origin, glm::vec3& direction) const {
     origin = _nearTopLeft + x*(_nearTopRight - _nearTopLeft) + y*(_nearBottomLeft - _nearTopLeft);

libraries/voxels/src/ViewFrustum.h

@@ -83,6 +83,8 @@ public:
     bool matches(const ViewFrustum& compareTo, bool debug = false) const;
     bool matches(const ViewFrustum* compareTo, bool debug = false) const { return matches(*compareTo, debug); };
 
+    void computeNormalToNearClipPlane(glm::vec3& normal) const;
+
     void computePickRay(float x, float y, glm::vec3& origin, glm::vec3& direction) const;
 
     void computeOffAxisFrustum(float& left, float& right, float& bottom, float& top, float& near, float& far,