diff --git a/interface/resources/shaders/SkyFromAtmosphere.frag b/interface/resources/shaders/SkyFromAtmosphere.frag index 37d26ba40a..b640f5f952 100644 --- a/interface/resources/shaders/SkyFromAtmosphere.frag +++ b/interface/resources/shaders/SkyFromAtmosphere.frag @@ -1,48 +1,106 @@ -#version 120 - -// -// For licensing information, see http://http.developer.nvidia.com/GPUGems/gpugems_app01.html: -// -// NVIDIA Statement on the Software -// -// The source code provided is freely distributable, so long as the NVIDIA header remains unaltered and user modifications are -// detailed. -// -// No Warranty -// -// THE SOFTWARE AND ANY OTHER MATERIALS PROVIDED BY NVIDIA ON THE ENCLOSED CD-ROM ARE PROVIDED "AS IS." NVIDIA DISCLAIMS ALL -// WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF TITLE, MERCHANTABILITY, -// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. -// -// Limitation of Liability -// -// NVIDIA SHALL NOT BE LIABLE TO ANY USER, DEVELOPER, DEVELOPER'S CUSTOMERS, OR ANY OTHER PERSON OR ENTITY CLAIMING THROUGH OR -// UNDER DEVELOPER FOR ANY LOSS OF PROFITS, INCOME, SAVINGS, OR ANY OTHER CONSEQUENTIAL, INCIDENTAL, SPECIAL, PUNITIVE, DIRECT -// OR INDIRECT DAMAGES (WHETHER IN AN ACTION IN CONTRACT, TORT OR BASED ON A WARRANTY), EVEN IF NVIDIA HAS BEEN ADVISED OF THE -// POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS SHALL APPLY NOTWITHSTANDING ANY FAILURE OF THE ESSENTIAL PURPOSE OF ANY -// LIMITED REMEDY. IN NO EVENT SHALL NVIDIA'S AGGREGATE LIABILITY TO DEVELOPER OR ANY OTHER PERSON OR ENTITY CLAIMING THROUGH -// OR UNDER DEVELOPER EXCEED THE AMOUNT OF MONEY ACTUALLY PAID BY DEVELOPER TO NVIDIA FOR THE SOFTWARE OR ANY OTHER MATERIALS. -// - -// -// Atmospheric scattering fragment shader -// -// Author: Sean O'Neil -// -// Copyright (c) 2004 Sean O'Neil -// - -uniform vec3 v3LightPos; -uniform float g; -uniform float g2; - -varying vec3 v3Direction; - - -void main (void) -{ - float fCos = dot(v3LightPos, v3Direction) / length(v3Direction); - float fMiePhase = 1.5 * ((1.0 - g2) / (2.0 + g2)) * (1.0 + fCos*fCos) / pow(1.0 + g2 - 2.0*g*fCos, 1.5); - gl_FragColor = gl_Color + fMiePhase * gl_SecondaryColor; - gl_FragColor.a = gl_FragColor.b; -} +#version 120 + +// +// For licensing information, see http://http.developer.nvidia.com/GPUGems/gpugems_app01.html: +// +// NVIDIA Statement on the Software +// +// The source code provided is freely distributable, so long as the NVIDIA header remains unaltered and user modifications are +// detailed. +// +// No Warranty +// +// THE SOFTWARE AND ANY OTHER MATERIALS PROVIDED BY NVIDIA ON THE ENCLOSED CD-ROM ARE PROVIDED "AS IS." NVIDIA DISCLAIMS ALL +// WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF TITLE, MERCHANTABILITY, +// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +// +// Limitation of Liability +// +// NVIDIA SHALL NOT BE LIABLE TO ANY USER, DEVELOPER, DEVELOPER'S CUSTOMERS, OR ANY OTHER PERSON OR ENTITY CLAIMING THROUGH OR +// UNDER DEVELOPER FOR ANY LOSS OF PROFITS, INCOME, SAVINGS, OR ANY OTHER CONSEQUENTIAL, INCIDENTAL, SPECIAL, PUNITIVE, DIRECT +// OR INDIRECT DAMAGES (WHETHER IN AN ACTION IN CONTRACT, TORT OR BASED ON A WARRANTY), EVEN IF NVIDIA HAS BEEN ADVISED OF THE +// POSSIBILITY OF SUCH DAMAGES. THESE LIMITATIONS SHALL APPLY NOTWITHSTANDING ANY FAILURE OF THE ESSENTIAL PURPOSE OF ANY +// LIMITED REMEDY. IN NO EVENT SHALL NVIDIA'S AGGREGATE LIABILITY TO DEVELOPER OR ANY OTHER PERSON OR ENTITY CLAIMING THROUGH +// OR UNDER DEVELOPER EXCEED THE AMOUNT OF MONEY ACTUALLY PAID BY DEVELOPER TO NVIDIA FOR THE SOFTWARE OR ANY OTHER MATERIALS. +// + +// +// Atmospheric scattering fragment shader +// +// Author: Sean O'Neil +// +// Copyright (c) 2004 Sean O'Neil +// + +uniform vec3 v3CameraPos; // The camera's current position +uniform vec3 v3InvWavelength; // 1 / pow(wavelength, 4) for the red, green, and blue channels +uniform float fInnerRadius; // The inner (planetary) radius +uniform float fKrESun; // Kr * ESun +uniform float fKmESun; // Km * ESun +uniform float fKr4PI; // Kr * 4 * PI +uniform float fKm4PI; // Km * 4 * PI +uniform float fScale; // 1 / (fOuterRadius - fInnerRadius) +uniform float fScaleDepth; // The scale depth (i.e. the altitude at which the atmosphere's average density is found) +uniform float fScaleOverScaleDepth; // fScale / fScaleDepth + +const int nSamples = 2; +const float fSamples = 2.0; + +uniform vec3 v3LightPos; +uniform float g; +uniform float g2; + +varying vec3 position; + +float scale(float fCos) +{ + float x = 1.0 - fCos; + return fScaleDepth * exp(-0.00287 + x*(0.459 + x*(3.83 + x*(-6.80 + x*5.25)))); +} + +void main (void) +{ + // Get the ray from the camera to the vertex, and its length (which is the far point of the ray passing through the atmosphere) + vec3 v3Pos = position; + vec3 v3Ray = v3Pos - v3CameraPos; + float fFar = length(v3Ray); + v3Ray /= fFar; + + // Calculate the ray's starting position, then calculate its scattering offset + vec3 v3Start = v3CameraPos; + float fHeight = length(v3Start); + float fDepth = exp(fScaleOverScaleDepth * (fInnerRadius - fHeight)); + float fStartAngle = dot(v3Ray, v3Start) / fHeight; + float fStartOffset = fDepth * scale(fStartAngle); + + // Initialize the scattering loop variables + //gl_FrontColor = vec4(0.0, 0.0, 0.0, 0.0); + float fSampleLength = fFar / fSamples; + float fScaledLength = fSampleLength * fScale; + vec3 v3SampleRay = v3Ray * fSampleLength; + vec3 v3SamplePoint = v3Start + v3SampleRay * 0.5; + + // Now loop through the sample rays + vec3 v3FrontColor = vec3(0.0, 0.0, 0.0); + for(int i=0; i