0031279: Visualization, TKOpenGl - environment background is misplaced within Ray-Tracing

Fixed problem with misplacing background texture in Ray-Tracing.

An environment background is always drawn using a perspective matrix.

src/OpenGl/OpenGl_View_Raytrace.cxx

@@ -2545,6 +2545,20 @@ Standard_Boolean OpenGl_View::setUniformState (const Standard_Integer        the
                   aDirects,
                   aViewPrjMat,
                   anUnviewMat);
+
+    if (myRenderParams.UseEnvironmentMapBackground
+     || myRaytraceParameters.CubemapForBack)
+    {
+      OpenGl_Mat4 aTempMat;
+      OpenGl_Mat4 aTempInvMat;
+      updatePerspCameraPT (myCamera->OrientationMatrixF(),
+                           aCntxProjectionState.Current(),
+                           theProjection,
+                           aTempMat,
+                           aTempInvMat,
+                           theWinSizeX,
+                           theWinSizeY);
+    }
   }
   else
   {

src/Shaders/RaytraceBase.fs

@@ -1023,6 +1023,7 @@ vec4 Radiance (in SRay theRay, in vec3 theInverse)
   int aTrsfId;
 
   float aRaytraceDepth = MAXFLOAT;
+  float aRefractionIdx = 0.0;
 
   for (int aDepth = 0; aDepth < NB_BOUNCES; ++aDepth)
   {
@@ -1034,11 +1035,30 @@ vec4 Radiance (in SRay theRay, in vec3 theInverse)
     {
       vec4 aColor = vec4 (0.0);
 
-      if (bool(uEnvMapForBack) || aWeight.w == 0.0f /* reflection */)
+      if (bool(uEnvMapForBack) || aWeight.w == 0.0 /* reflection */)
       {
-        float aTime = IntersectSphere (theRay, uSceneRadius);
+        float aRadius = uSceneRadius;
+        vec3 aTexCoord = vec3 (0.0);
 
-        aColor = FetchEnvironment (theRay.Direct * aTime + theRay.Origin, uSceneRadius, aWeight.w != 0.0);
+        if (aDepth == 0 || (aRefractionIdx == 1.0 && aWeight.w != 0.0))
+        {
+          vec2 aPixel = uEyeSize * (vPixel - vec2 (0.5)) * 2.0;
+          vec2 anAperturePnt = sampleUniformDisk() * uApertureRadius;
+          vec3 aLocalDir = normalize (vec3 (aPixel * uFocalPlaneDist - anAperturePnt, uFocalPlaneDist));
+          vec3 aDirect = uEyeView * aLocalDir.z +
+                         uEyeSide * aLocalDir.x +
+                         uEyeVert * aLocalDir.y;
+          
+          aTexCoord = aDirect * uSceneRadius;
+          aRadius = length (aTexCoord);
+        }
+        else
+        {
+          float aTime = IntersectSphere (theRay, uSceneRadius);
+          aTexCoord = theRay.Direct * aTime + theRay.Origin;
+        }
+
+        aColor = FetchEnvironment (aTexCoord, aRadius, aWeight.w != 0.0);
       }
       else
       {
@@ -1167,6 +1187,7 @@ vec4 Radiance (in SRay theRay, in vec3 theInverse)
     if (aOpacity.x != 1.0f)
     {
       aWeight *= aOpacity.y;
+      aRefractionIdx = aOpacity.z;
 
       if (aOpacity.z != 1.0f)
       {

src/Shaders/Shaders_RaytraceBase_fs.pxx

@@ -1026,6 +1026,7 @@ static const char Shaders_RaytraceBase_fs[] =
   "  int aTrsfId;\n"
   "\n"
   "  float aRaytraceDepth = MAXFLOAT;\n"
+  "  float aRefractionIdx = 0.0;\n"
   "\n"
   "  for (int aDepth = 0; aDepth < NB_BOUNCES; ++aDepth)\n"
   "  {\n"
@@ -1037,11 +1038,30 @@ static const char Shaders_RaytraceBase_fs[] =
   "    {\n"
   "      vec4 aColor = vec4 (0.0);\n"
   "\n"
-  "      if (bool(uEnvMapForBack) || aWeight.w == 0.0f /* reflection */)\n"
+  "      if (bool(uEnvMapForBack) || aWeight.w == 0.0 /* reflection */)\n"
   "      {\n"
-  "        float aTime = IntersectSphere (theRay, uSceneRadius);\n"
+  "        float aRadius = uSceneRadius;\n"
+  "        vec3 aTexCoord = vec3 (0.0);\n"
   "\n"
-  "        aColor = FetchEnvironment (theRay.Direct * aTime + theRay.Origin, uSceneRadius, aWeight.w != 0.0);\n"
+  "        if (aDepth == 0 || (aRefractionIdx == 1.0 && aWeight.w != 0.0))\n"
+  "        {\n"
+  "          vec2 aPixel = uEyeSize * (vPixel - vec2 (0.5)) * 2.0;\n"
+  "          vec2 anAperturePnt = sampleUniformDisk() * uApertureRadius;\n"
+  "          vec3 aLocalDir = normalize (vec3 (aPixel * uFocalPlaneDist - anAperturePnt, uFocalPlaneDist));\n"
+  "          vec3 aDirect = uEyeView * aLocalDir.z +\n"
+  "                         uEyeSide * aLocalDir.x +\n"
+  "                         uEyeVert * aLocalDir.y;\n"
+  "          \n"
+  "          aTexCoord = aDirect * uSceneRadius;\n"
+  "          aRadius = length (aTexCoord);\n"
+  "        }\n"
+  "        else\n"
+  "        {\n"
+  "          float aTime = IntersectSphere (theRay, uSceneRadius);\n"
+  "          aTexCoord = theRay.Direct * aTime + theRay.Origin;\n"
+  "        }\n"
+  "\n"
+  "        aColor = FetchEnvironment (aTexCoord, aRadius, aWeight.w != 0.0);\n"
   "      }\n"
   "      else\n"
   "      {\n"
@@ -1170,6 +1190,7 @@ static const char Shaders_RaytraceBase_fs[] =
   "    if (aOpacity.x != 1.0f)\n"
   "    {\n"
   "      aWeight *= aOpacity.y;\n"
+  "      aRefractionIdx = aOpacity.z;\n"
   "\n"
   "      if (aOpacity.z != 1.0f)\n"
   "      {\n"

tests/v3d/raytrace/bug31279

@@ -0,0 +1,18 @@
+puts "============"
+puts "0031279: Visualization, TKOpenGl - environment background is misplaced within Ray-Tracing"
+puts "============"
+puts ""
+
+source $env(CSF_OCCTSamplesPath)/tcl/raytrace.tcl
+vrenderparams -env
+vcamera -persp
+vviewparams -scale 1.3 -proj 0.57 -0.57 0.57 -up -0.4 0.4 0.8 -at -62 -111 -15
+vtextureenv on 1
+
+if { [vreadpixel 100 100 rgb name] == "BLACK" } { puts "ERROR: background is misplaced" }
+
+vcamera -persp
+vdump $imagedir/${casename}_persp.png
+
+vcamera -ortho
+vdump $imagedir/${casename}_ortho.png