Experiment on the volume rendering shaders from Radium.

src/libRender/RadiumNBR/Passes/VolumePass.cpp

@@ -178,6 +178,9 @@ void VolumeLightingPass::execute( const Ra::Engine::Data::ViewingParameters& vie
     GL_ASSERT( glDisable( GL_BLEND ) );
 }
 
+// for now, Radium shaders need a light source with the right emission power. Volume gets
+// dark when rendered with headlight. So, we use or own shaders that multitply by 100 the source color
+//#define USE_RADIUM_VOLUMETRIC_SHADERS
 bool VolumeLightingPass::buildRenderTechnique( const Ra::Engine::Rendering::RenderObject* ro,
                                                Ra::Engine::Rendering::RenderTechnique& rt ) const {
     std::string resourcesRootDir = getResourcesDir();
@@ -185,6 +188,10 @@ bool VolumeLightingPass::buildRenderTechnique( const Ra::Engine::Rendering::Rend
     // Only volumes are used by this pass
     if ( mat->getMaterialAspect() != Ra::Engine::Data::Material::MaterialAspect::MAT_DENSITY )
     { return false; }
+#ifdef USE_RADIUM_VOLUMETRIC_SHADERS
+    auto passconfig = Ra::Engine::Data::ShaderConfigurationFactory::getConfiguration( "Volumetric" );
+    rt.setConfiguration( *passconfig, passIndex() );
+#else
     if ( auto cfg = Ra::Engine::Data::ShaderConfigurationFactory::getConfiguration(
              {"VolumeLightingPass::" + mat->getMaterialName()} ) )
     { rt.setConfiguration( *cfg, passIndex() ); }
@@ -205,6 +212,7 @@ bool VolumeLightingPass::buildRenderTechnique( const Ra::Engine::Rendering::Rend
         // Add to the RenderTechniq
         rt.setConfiguration( theConfig, passIndex() );
     }
+#endif
     rt.setParametersProvider( mat, passIndex() );
 
     return true;

src/libRender/RadiumNBR/Passes/VolumePass.hpp

@@ -25,9 +25,6 @@ namespace RadiumNBR {
 class VolumeLightingPass : public RenderPass
 {
   public:
-    using RGBSpectrum    = std::array<float, 3>; // pbrt::Spectrum
-    using TransferMatrix = std::vector<RGBSpectrum>;
-
     VolumeLightingPass( const std::vector<RenderObjectPtr>* objectsToRender,
                         const Ra::Core::Utils::Index& idx );
     ~VolumeLightingPass() override;

src/libRender/RadiumNBR/Shaders/VolumeLightingPass/volume.frag.glsl

@@ -121,7 +121,7 @@ vec3 inscatter(Material volume, vec3 p, vec3 dir, Light l) {
     vec3 dirLight = getLightDirection(l, p);
     return Inv4Pi*volume.sigma_s.rgb * phaseHG(dot(dir, dirLight), volume.g) * lightColor(volume, p, l);
 }
-    #endif
+#endif
 
 /* ---------------------------------------------------------------------------------------- */
 /*
@@ -201,6 +201,7 @@ void main() {
     }
     // compute the light information in canonical space
     Light l = transformLight(light, material.modelToDensity * world2model );
+    l.color.rgb *= 100;
     switch (light.type) {
         case 0: break;
         case 1: l.point.position/= texSize;