From 8d5f01e58cc3c55681cc077216628c625fb333ba Mon Sep 17 00:00:00 2001
From: Michael Migliore <mcmigliore@gmail.com>
Date: Wed, 5 Jun 2024 17:21:48 +0200
Subject: [PATCH] PBR Neutral tone mapper
---
.../release/dev/pbr-neutral-tone-mapping.md | 4 ++++
.../Testing/Cxx/TestToneMappingPass.cxx | 22 ++++++++++---------
.../Baseline/TestToneMappingPass.png.sha512 | 2 +-
Rendering/OpenGL2/vtkToneMappingPass.cxx | 19 ++++++++++++++++
Rendering/OpenGL2/vtkToneMappingPass.h | 5 +++--
5 files changed, 39 insertions(+), 13 deletions(-)
create mode 100644 Documentation/release/dev/pbr-neutral-tone-mapping.md
diff --git a/Documentation/release/dev/pbr-neutral-tone-mapping.md b/Documentation/release/dev/pbr-neutral-tone-mapping.md
new file mode 100644
index 00000000000..c0e85f5a760
--- /dev/null
+++ b/Documentation/release/dev/pbr-neutral-tone-mapping.md
@@ -0,0 +1,4 @@
+## PBR Neutral tone mapping
+
+A new alternative tone mapping method has been added to `vtkToneMappingPass`.
+It's based on the reference implementation of Khronos PBR Neutral.
diff --git a/Rendering/OpenGL2/Testing/Cxx/TestToneMappingPass.cxx b/Rendering/OpenGL2/Testing/Cxx/TestToneMappingPass.cxx
index 164cc2d6a0e..04a375d1fee 100644
--- a/Rendering/OpenGL2/Testing/Cxx/TestToneMappingPass.cxx
+++ b/Rendering/OpenGL2/Testing/Cxx/TestToneMappingPass.cxx
@@ -14,6 +14,7 @@
#include "vtkOpaquePass.h"
#include "vtkOpenGLRenderer.h"
#include "vtkPolyDataMapper.h"
+#include "vtkProperty.h"
#include "vtkRenderPassCollection.h"
#include "vtkRenderWindow.h"
#include "vtkRenderWindowInteractor.h"
@@ -24,7 +25,7 @@
int TestToneMappingPass(int argc, char* argv[])
{
vtkNew<vtkRenderWindow> renWin;
- renWin->SetSize(400, 800);
+ renWin->SetSize(900, 900);
vtkNew<vtkRenderWindowInteractor> iren;
iren->SetRenderWindow(renWin);
@@ -33,8 +34,7 @@ int TestToneMappingPass(int argc, char* argv[])
sphere->SetThetaResolution(20);
sphere->SetPhiResolution(20);
- double y = 0.0;
- for (int i = 0; i < 8; i++)
+ for (int i = 0; i < 9; i++)
{
vtkNew<vtkRenderer> renderer;
@@ -84,19 +84,20 @@ int TestToneMappingPass(int argc, char* argv[])
toneMappingP->SetGenericFilmicUncharted2Presets();
toneMappingP->SetUseACES(false);
break;
+ case 8:
+ toneMappingP->SetToneMappingType(vtkToneMappingPass::NeutralPBR);
+ break;
}
toneMappingP->SetDelegatePass(cameraP);
vtkOpenGLRenderer::SafeDownCast(renderer)->SetPass(toneMappingP);
- double x = 0.5 * (i & 1);
- if (i)
- {
- y += 1 / 4.f * !(i & 1);
- }
+ double oneThird = 1.0 / 3.0;
+
+ double x = (i % 3) * oneThird;
+ double y = (i / 3) * oneThird;
- renderer->SetViewport(x, y, x + 0.5, y + 1 / 4.f);
- renderer->SetBackground(0.5, 0.5, 0.5);
+ renderer->SetViewport(x, y, x + oneThird, y + oneThird);
renWin->AddRenderer(renderer);
// add one light in front of the object
@@ -141,6 +142,7 @@ int TestToneMappingPass(int argc, char* argv[])
vtkNew<vtkActor> actor;
actor->SetMapper(mapper);
+ actor->GetProperty()->SetInterpolationToPBR();
renderer->AddActor(actor);
renderer->ResetCamera();
diff --git a/Rendering/OpenGL2/Testing/Data/Baseline/TestToneMappingPass.png.sha512 b/Rendering/OpenGL2/Testing/Data/Baseline/TestToneMappingPass.png.sha512
index 741f700d08e..ab82260e07c 100644
--- a/Rendering/OpenGL2/Testing/Data/Baseline/TestToneMappingPass.png.sha512
+++ b/Rendering/OpenGL2/Testing/Data/Baseline/TestToneMappingPass.png.sha512
@@ -1 +1 @@
-4595f98960d268ccf75b17b50761f5559aab38e975f0c74fb61687ea1ca0ef8d1260661bb317d074dc8824f3d4e8aee0378d3dd538c038bcf06a59bdde042ad3
+af28d7481039a61d908c16db917bf1655c3b8931b2ab771b7f6dcd39825efc6c3ee5072b52301a4d6c1795597f1305eccee1556afff45e71b681eca50ce40418
diff --git a/Rendering/OpenGL2/vtkToneMappingPass.cxx b/Rendering/OpenGL2/vtkToneMappingPass.cxx
index 9aa77c9adb7..d4f6c127abc 100644
--- a/Rendering/OpenGL2/vtkToneMappingPass.cxx
+++ b/Rendering/OpenGL2/vtkToneMappingPass.cxx
@@ -188,6 +188,25 @@ void vtkToneMappingPass::Render(const vtkRenderState* s)
" toned = clamp(toned, vec3(0.f), vec3(1.f));\n"
"//VTK::FSQ::Impl");
break;
+ case NeutralPBR:
+ // adapted from Khronos reference implementation:
+ // https://github.com/KhronosGroup/ToneMapping/blob/main/PBR_Neutral/pbrNeutral.glsl
+ vtkShaderProgram::Substitute(FSSource, "//VTK::FSQ::Impl",
+ " const float startCompression = 0.8 - 0.04;\n"
+ " const float desaturation = 0.15;\n"
+ " float x = min(color.r, min(color.g, color.b));\n"
+ " float offset = x < 0.08 ? x - 6.25 * x * x : 0.04;\n"
+ " vec3 toned = color - vec3(offset);\n"
+ " float peak = max(toned.r, max(toned.g, toned.b));\n"
+ " if (peak >= startCompression)\n"
+ " {\n"
+ " const float d = 1. - startCompression;\n"
+ " float newPeak = 1. - d * d / (peak + d - startCompression);\n"
+ " toned *= newPeak / peak;\n"
+ " float g = 1. - 1. / (desaturation * (peak - newPeak) + 1.);\n"
+ " toned = mix(toned, newPeak * vec3(1, 1, 1), g);\n"
+ " }\n"
+ "//VTK::FSQ::Impl");
}
// Recorrect gamma and output
diff --git a/Rendering/OpenGL2/vtkToneMappingPass.h b/Rendering/OpenGL2/vtkToneMappingPass.h
index c0f1a5dcf37..67139b259ee 100644
--- a/Rendering/OpenGL2/vtkToneMappingPass.h
+++ b/Rendering/OpenGL2/vtkToneMappingPass.h
@@ -68,7 +68,8 @@ public:
Clamp = 0,
Reinhard = 1,
Exponential = 2,
- GenericFilmic = 3
+ GenericFilmic = 3,
+ NeutralPBR = 4
};
///@{
@@ -76,7 +77,7 @@ public:
* Get/Set the tone mapping type.
* Default is GenericFilmic
*/
- vtkSetClampMacro(ToneMappingType, int, 0, 3);
+ vtkSetClampMacro(ToneMappingType, int, 0, 4);
vtkGetMacro(ToneMappingType, int);
///@}
--
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