Ray-Tracing now handles IBL and background cubemaps in similar way as PBR.
Ambient light source is handled by Ray-Tracing in similar way as PBR,
e.g. as coefficient for environment map (IBL) or as constant light source.
Test script generating PBR spheres has been moved to Samples
and now shared by PBR and Path-Tracing tests.
Added new class RWGltf_CafWriter for exporting XCAF document into glTF file
as well as Draw Harness command WriteGltf.
Added auxiliary method OSD_Path::FileNameAndExtension() splitting file name into Name and Extension.
Metallic-Roughness shading model Graphic3d_TOSM_PBR has been implemented.
New materials descriptors Graphic3d_PBRMaterial have been added to Graphic3d_MaterialAspect.
PBR shading model requires OpenGL 3.0+ or OpenGL ES 3.0+ hardware.
Environment cubemap is expected to be provided for realistic look of metallic materials.
occLight_IsHeadlight() now returns bool instead of int.
Avoid using lowp for enumerations to workaround occLight_IsHeadlight()
ignorance on Adreno 308 caused by some GLSL optimizator bugs.
OpenGl_Texture::EstimatedDataSize() - fixed estimation for Cubemap textures.
OpenGl_Sampler::applySamplerParams() - fixed uninitialized GL_TEXTURE_WRAP_R in case of GL_TEXTURE_CUBE_MAP target.
