This commit provides useful functionality for path tracing rendering core.
1) Graphic3d_RenderingParams class was extended with additional AdaptiveScreenSampling option (disabled by default).
If this option is enabled, path tracing tries to adjust the number of samples for different screen areas.
In this way, the more complex areas (from the point of light conditions) are sampled more intensively,
while the simple areas are sampled very rarely.
For example, caustics and glossy reflections are typical candidates for more precise sampling.
In general, this allows to equalize image convergence and not to waste resources for already converged areas.
It is also possible to visualize sampling densities by enabling ShowSamplingTiles option
(activating and deactivating this option does not affect on the accumulated image).
2) Mixing OpenGL and ray-tracing output has been changed.
Now blending is performed using OpenGL functionality, while ray-tracing shaders only output correct Z-value.
Test case bugs vis bug27083 has been updated,
since the alpha value is now correctly set by Ray-Tracing to 1, opaque.
OpenGl_CappingAlgo::RenderCapping() now updates clipping state in Shader Manager.
OpenGl_View::render() clipping state setup has been moved to OpenGl_View::renderScene().
OpenGl_ShaderManager now converts position to homogeneous coordinates within clipping code GLSL.
This fixes capping plane rendering with clipping planes applied.
Fixed possible Clipping planes misconfiguration when FFP is used;
error-prone OpenGl_Clipping::AddWorldLazy() method has been dropped.
In frames of this issue binary BVH tree produced by building algorithms was collapsed into 4-ary BVH (QBVH).
The BVH traversal code in GLSL was modified to process such trees correctly.
This allows to implore thread coherence, decrease BVH memory consumption (~2 times), and use traversal stack of the half size.
As a result, ray tracing scalability is improved, as well as rendering performance. For various setups, speedup is 12-18%.
For FSAA mode we now store the depth values from first sample in myRaytraceFBO1 and do not modify it while collecting the rest of samples.
When all samples are gathered we fetch color from myRaytraceFBO2 and depth from myRaytraceFBO1 and display it to the current FBO.
Test bugs vis bug27337 added.
View-projection matrix was added to raytrace shaders (as uniform) in order to compute correct depth values for OpenGL.
For path tracing the additional depth buffer sampler was added to Display.fs program. It allows propagation of depth values from internal FBO to resulting FBO.
The old approach of mixing of OpenGL and ray-tracing graphics was kept in order to keep correct blending of transparent ray-traced objects with non-transparent OpenGL objects.
OpenGl_Clipping - do not setup clipping planes using FFP when it is disabled.
OpenGl_ShaderManager - apply 2d texture coordinates transformation in GLSL programs.
OpenGl_Context::SetTextureMatrix() - move texture matrix assignment from OpenGl_Workspace::setTextureParams() to OpenGl_Context.
Add test case demo/samples/dimensionsglsl with FFP turned OFF.
Add test case v3d/glsl/texture_trsf applying texture transformation.
Small correction of test case for issue CR26122
Replace 64-bit handles of bindless textures by uvec2 type in GLSL code for compatibility with AMD drivers.
OpenGl_View::initProgram() - fix NULL-dereference.
Automatic upgrade of OCCT code by command "occt_upgrade . -nocdl":
- WOK-generated header files from inc and sources from drv are moved to src
- CDL files removed
- All packages are converted to nocdlpack
Backside triangles are handled correctly by implementing two-sided lighting model. Ray-tracing shader was optimized (up to 25% performance increase).
Test case for CR25833
This patch eliminates 3 samplers used in ray-tracing mode:
//! Texture buffer of data records of bottom-level BVH nodes.
Handle(OpenGl_TextureBufferArb) myObjectNodeInfoTexture;
//! Texture buffer of minimum points of bottom-level BVH nodes.
Handle(OpenGl_TextureBufferArb) myObjectMinPointTexture;
//! Texture buffer of maximum points of bottom-level BVH nodes.
Handle(OpenGl_TextureBufferArb) myObjectMaxPointTexture;
Serialized data contained in corresponding texture buffers were added to global scene buffers:
//! Texture buffer of data records of high-level BVH nodes.
Handle(OpenGl_TextureBufferArb) mySceneNodeInfoTexture;
//! Texture buffer of minimum points of high-level BVH nodes.
Handle(OpenGl_TextureBufferArb) mySceneMinPointTexture;
//! Texture buffer of maximum points of high-level BVH nodes.
Handle(OpenGl_TextureBufferArb) mySceneMaxPointTexture;
This modifications leads also to small performance improvement (~2%) due to higher texture cache efficiency. Some modifications in traversal function (GLSL code) also improve performance (~3%).
Enumerations Visual3d_TypeOfModel, V3d_TypeOfShadingModel.
- Remove unused values V3d_MULTICOLOR, V3d_HIDDEN, Visual3d_TOM_INTERP_COLOR.
- Add per-pixel shading mode - V3d_PHONG, Visual3d_TOM_FRAGMENT.
Draw Harness command vrenderparams.
Add option -shadingModel to setup Shading Model.
OpenGl_Caps::ffpEnable - new option to switch FFP/built-in GLSL programs.
OpenGl_ShaderManager - add built-in GLSL programs.
Draw Harness command vcaps.
- Fix command syntax to meet coding rules.
- Add option -ffp to activate/disable built-in GLSL programs.
GLSL API changes.
- Rename vertex attribute occColor -> occVertColor.
- Introduce vec4 occColor uniform variable for light-less shaders.
- Introduce float occPointSize uniform variable for marker programs.
OpenGl_VertexBuffer::bindAttribute() - activate normalization for non-GL_FLOAT types,
since color attribute is defined as 32-bit vector of 4 unsigned byte values.
OpenGl_Context - add methods SetColor4fv() and SetPointSize()
for parameters redirection to active GLSL program
(as alternative to glColor4fv() and glPointSize()).
OpenGl_ShaderProgram - define default precision for float types
in Fragment Shader within OpenGL ES 2.0+ context.
OpenGl_AspectMarker, initialize Aspect_TOM_O_POINT display list
in the same way as sprite texture.
OpenGl_Texture, do not use sized internal formats on OpenGL ES.
Inherit NCollection_Buffer from Standard_Transient, do not use incomplete NCollection_Handle.
OpenGl_Context, add methods ActiveProgram(),BindProgram()
to manage currently active GLSL program.
Add method ::ToUseVbo().
OpenGl_ShaderProgram, setup locations of pre-defined vertex attributes
occVertex, occNormal, occTexCoord, occColor before linkage.
Remove methods OpenGl_ShaderProgram::Bind(), ::BindWithVariables()
and ::Unbind() - OpenGl_Context::BindProgram() should be used instead.
Introduce class OpenGl_VertexBufferCompat, which emulates VBO
behavior on systems without VBO (compatibility with broken OpenGL drivers on Windows).
OpenGl_PrimitiveArray - use OpenGl_VertexBufferCompat when VBO is unavailable,
remove duplicated code. Use OpenGl_VertexBuffer::HasNormalAttribute()
method to activate lighting.
OpenGl_Text - use OpenGl_VertexBufferCompat, eliminate duplicated code.
Changes in OpenGl_VertexBuffer, drop methods BindFixed()/UnbindFixed().
Superseded by new methods BindAllAttributes()/UnbindAllAttributes()
which handle active GLSL program, when it is set.
OpenGl_GraphicDriver::Redraw() - do not recompute structures more than required
OpenGl_Workspace::Raytrace() - bind proper FBO before clearing it
Visual3d_View::Redraw() - perform automatic 2nd redraw on device lost
Refraction index passed to raytrace shader.
For transparent objects implemented ray refraction according to refraction index.
Transparent materials modified to look better with refractions.
License statement text corrected; compiler warnings caused by Bison 2.41 disabled for MSVC; a few other compiler warnings on 54-bit Windows eliminated by appropriate type cast
Wrong license statements corrected in several files.
Copyright and license statements added in XSD and GLSL files.
Copyright year updated in some files.
Obsolete documentation files removed from DrawResources.
