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0030476: Visualization, Path Tracing - Adaptive Screen Sampling leads to unstable results

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OpenGl_View::runPathtrace() has been extended with alternative multi-pass
Adaptive Screen Sampling mode, not relying on atomic floating point operations.
Although atomic operations on floats allows single-pass rendering,
such operations leads to instability in case of different calculation order.
Atomic float operations are also currently supported only by single GPU vendor.

Fixed GLSL compilation on Intel drivers (follow ARB_shader_image_load_store
specs rather than EXT_shader_image_load_store).

Graphic3d_RenderingParams::AdaptiveScreenSamplingAtomic option has been added
to activate 1-pass Adaptive Screen Sampling mode when supported by hardware.

vfps command has been extended with -duration argument allowing to limit command execution time.
vactivate command has been extended with -noUpdate argument.
This commit is contained in:
kgv
2019-02-11 18:00:35 +03:00
committed by apn
parent 66d1cdc65d
commit e084dbbc20
18 changed files with 488 additions and 147 deletions
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92
src/OpenGl/OpenGl_TileSampler.cxx
View File

@@ -18,6 +18,9 @@
#include <Graphic3d_RenderingParams.hxx>
#include <TCollection_ExtendedString.hxx>
// define to debug algorithm values
//#define RAY_TRACE_PRINT_DEBUG_INFO
//=======================================================================
//function : OpenGl_TileSampler
//purpose :
@@ -68,6 +71,8 @@ void OpenGl_TileSampler::GrabVarianceMap (const Handle(OpenGl_Context)& theConte
for (Standard_Size aRowIter = 0; aRowIter < myVarianceMap.SizeY; ++aRowIter)
{
const int aRawValue = myVarianceRaw.Value (aRowIter, aColIter);
Standard_RangeError_Raise_if (aRawValue < 0, "Internal Error: signed integer overflow within OpenGl_TileSampler");
float& aTile = myVarianceMap.ChangeValue (aRowIter, aColIter);
aTile = aFactor * float(aRawValue);
aTile *= 1.0f / tileArea ((int )aColIter, (int )aRowIter); // average error over the tile
@@ -87,6 +92,29 @@ void OpenGl_TileSampler::GrabVarianceMap (const Handle(OpenGl_Context)& theConte
myMarginalMap[aX] += myMarginalMap[aX - 1];
}
}
#ifdef RAY_TRACE_PRINT_DEBUG_INFO
dumpMap (std::cerr, myVarianceRaw, "OpenGl_TileSampler, Variance map");
#endif
}
//=======================================================================
//function : dumpMap
//purpose :
//=======================================================================
void OpenGl_TileSampler::dumpMap (std::ostream& theStream,
const Image_PixMapTypedData<int>& theMap,
const char* theTitle) const
{
theStream << theTitle << " " << theMap.SizeX << "x" << theMap.SizeY << " (tile " << myTileSize << "x" << myTileSize << ")" << ":\n";
for (Standard_Size aRowIter = 0; aRowIter < theMap.SizeY; ++aRowIter)
{
for (Standard_Size aColIter = 0; aColIter < theMap.SizeX; ++aColIter)
{
theStream << " [" << theMap.Value (aRowIter, aColIter) << "]";
}
theStream << "\n";
}
}
//=======================================================================
@@ -148,6 +176,10 @@ void OpenGl_TileSampler::SetSize (const Graphic3d_RenderingParams& theParams,
myTiles.Init (anAlloc, aNbTilesX, aNbTilesY);
myTiles.Init (1);
myTileSamples.SetTopDown (true);
myTileSamples.Init (myTiles.Allocator(), aNbTilesX, aNbTilesY);
myTileSamples.Init (1);
myVarianceMap.SetTopDown (true);
myVarianceMap.Init (myTiles.Allocator(), myTiles.SizeX, myTiles.SizeY);
myVarianceMap.Init (0.0f);
@@ -185,18 +217,28 @@ void OpenGl_TileSampler::SetSize (const Graphic3d_RenderingParams& theParams,
}
//=======================================================================
//function : UploadOffsets
//function : upload
//purpose :
//=======================================================================
bool OpenGl_TileSampler::UploadOffsets (const Handle(OpenGl_Context)& theContext,
const Handle(OpenGl_Texture)& theOffsetsTexture,
const bool theAdaptive)
bool OpenGl_TileSampler::upload (const Handle(OpenGl_Context)& theContext,
const Handle(OpenGl_Texture)& theSamplesTexture,
const Handle(OpenGl_Texture)& theOffsetsTexture,
const bool theAdaptive)
{
if (myTiles.IsEmpty())
{
return false;
}
// Fill in myTiles map with a number of passes (samples) per tile.
// By default, all tiles receive 1 sample, but basing on visual error level (myVarianceMap),
// this amount is re-distributed from tiles having smallest error take 0 samples to tiles having larger error.
// This redistribution is smoothed by Halton sampler.
//
// myOffsets map is filled as redirection of currently rendered tile to another one
// so that tiles having smallest error level have 0 tiles redirected from,
// while tiles with great error level might be rendered more than 1.
// This map is used within single-pass rendering method requiring atomic float operation support from hardware.
myTiles.Init (0);
Image_PixMapTypedData<Graphic3d_Vec2i>& anOffsets = theAdaptive ? myOffsetsShrunk : myOffsets;
anOffsets.Init (Graphic3d_Vec2i (-1, -1));
@@ -210,7 +252,49 @@ bool OpenGl_TileSampler::UploadOffsets (const Handle(OpenGl_Context)& theContext
}
}
#ifdef RAY_TRACE_PRINT_DEBUG_INFO
dumpMap (std::cerr, myTiles, "OpenGl_TileSampler, Samples");
#endif
// Fill in myTileSamples map from myTiles with an actual number of Samples per Tile as multiple of Tile Area
// (e.g. tile that should be rendered ones will have amount of samples equal to its are 4x4=16).
// This map is used for discarding tile fragments having <=0 of samples left within multi-pass rendering.
myTileSamples.Init (0);
for (Standard_Size aRowIter = 0; aRowIter < myTiles.SizeY; ++aRowIter)
{
for (Standard_Size aColIter = 0; aColIter < myTiles.SizeX; ++aColIter)
{
myTileSamples.ChangeValue (aRowIter, aColIter) = tileArea ((int )aColIter, (int )aRowIter) * myTiles.Value (aRowIter, aColIter);
}
}
bool hasErrors = false;
if (!theSamplesTexture.IsNull())
{
theSamplesTexture->Bind (theContext);
theContext->core11fwd->glPixelStorei (GL_UNPACK_ALIGNMENT, 1);
#if !defined(GL_ES_VERSION_2_0)
theContext->core11fwd->glPixelStorei (GL_UNPACK_ROW_LENGTH, 0);
#endif
if (theSamplesTexture->SizeX() == (int )myTileSamples.SizeX
&& theSamplesTexture->SizeY() == (int )myTileSamples.SizeY)
{
theContext->core11fwd->glTexSubImage2D (GL_TEXTURE_2D, 0, 0, 0, (int )myTileSamples.SizeX, (int )myTileSamples.SizeY, GL_RED_INTEGER, GL_INT, myTileSamples.Data());
if (theContext->core11fwd->glGetError() != GL_NO_ERROR)
{
hasErrors = true;
theContext->PushMessage (GL_DEBUG_SOURCE_APPLICATION, GL_DEBUG_TYPE_ERROR, 0, GL_DEBUG_SEVERITY_MEDIUM,
"Error! Failed to upload tile samples map on the GPU");
}
}
else
{
hasErrors = true;
}
theSamplesTexture->Unbind (theContext);
}
if (!theOffsetsTexture.IsNull())
{
if (theOffsetsTexture->SizeX() != (int )anOffsets.SizeX