diff --git a/Documentation/release/dev/fix-shadowmap-light.md b/Documentation/release/dev/fix-shadowmap-light.md
new file mode 100644
index 0000000000000000000000000000000000000000..e22d1d3d77878b465290c7f58cce2060e42fa43d
--- /dev/null
+++ b/Documentation/release/dev/fix-shadowmap-light.md
@@ -0,0 +1,9 @@
+## Fix light transforms when computing shadow maps
+
+The `vtkShadowMapBakerPass` computes shadow maps for each light by simulating a `vtkCamera` for each
+light and compositing the rendered images. However, an unintentional side-effect of this was that
+the original light's transforms were being affected by this. In other words, the lights would be
+corrupt after the shadow map computation. To circumvent this, we cache the light
+transforms prior to the shadow map computation and then reset them after.
+
+
diff --git a/Rendering/OpenGL2/Testing/Cxx/TestShadowMapBakerPass.cxx b/Rendering/OpenGL2/Testing/Cxx/TestShadowMapBakerPass.cxx
index 27c1f1a8b849287c0458ca049cdf697b5e6935ec..8c5dc323ab10c80f8780bab4c8cb2b4ebfe9af28 100644
--- a/Rendering/OpenGL2/Testing/Cxx/TestShadowMapBakerPass.cxx
+++ b/Rendering/OpenGL2/Testing/Cxx/TestShadowMapBakerPass.cxx
@@ -51,7 +51,6 @@ int TestShadowMapBakerPass(int argc, char* argv[])
delete[] fileName;
mapper->SetInputConnection(reader->GetOutputPort());
- // mapper->SetInputConnection(norms->GetOutputPort());
actor->SetMapper(mapper);
actor->GetProperty()->SetAmbientColor(0.2, 0.2, 1.0);
actor->GetProperty()->SetDiffuseColor(1.0, 0.65, 0.7);
diff --git a/Rendering/OpenGL2/Testing/Cxx/TestShadowMapPass.cxx b/Rendering/OpenGL2/Testing/Cxx/TestShadowMapPass.cxx
index 4c6d8d620fe475c553b43eb145d92babd26ee207..2b82e9a9c8d409d3c9f84c45306a0cf1274c454d 100644
--- a/Rendering/OpenGL2/Testing/Cxx/TestShadowMapPass.cxx
+++ b/Rendering/OpenGL2/Testing/Cxx/TestShadowMapPass.cxx
@@ -41,20 +41,29 @@ int TestShadowMapPass(int argc, char* argv[])
vtkNew<vtkRenderWindowInteractor> iren;
iren->SetRenderWindow(renderWindow);
+ // Add a couple of additional lights
vtkNew<vtkLight> light1;
- light1->SetFocalPoint(0, 0, 0);
+ light1->SetFocalPoint(1, 0, 1);
light1->SetPosition(0, 1, 0.2);
light1->SetColor(0.95, 0.97, 1.0);
light1->SetIntensity(0.8);
renderer->AddLight(light1);
vtkNew<vtkLight> light2;
- light2->SetFocalPoint(0, 0, 0);
- light2->SetPosition(1.0, 1.0, 1.0);
+ light2->SetFocalPoint(0, 0, 1);
+ light2->SetPosition(0.2, 0.5, 0.5);
light2->SetColor(1.0, 0.8, 0.7);
- light2->SetIntensity(0.3);
+ light2->SetIntensity(0.5);
renderer->AddLight(light2);
+ vtkNew<vtkLight> light3;
+ light3->SetFocalPoint(-0.1, -0.5, -0.5);
+ light3->SetPosition(0.2, 0.5, 0.5);
+ light3->SetColor(1.0, 0.8, 0.7);
+ light3->SetPositional(true);
+ light3->SetIntensity(0.3);
+ renderer->AddLight(light3);
+
const char* fileName = vtkTestUtilities::ExpandDataFileName(argc, argv, "Data/dragon.ply");
vtkNew<vtkPLYReader> reader;
reader->SetFileName(fileName);
diff --git a/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapBakerPass.png.sha512 b/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapBakerPass.png.sha512
index 0767af628c04d84c37dd774f1bac3026c9bf22b7..bb16a9c29dff48e34f8f8051c310bece5cd06b9b 100644
--- a/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapBakerPass.png.sha512
+++ b/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapBakerPass.png.sha512
@@ -1 +1 @@
-8e1cdfe8edc9fbe88c027fca7521e8f6c2dadb16d9b3c99baef2b093bfb42fc3aa56e251f3d5b02ee66a67f5c86cf4e92a9b0901cfb4cbd9e58f04b7f5e1a333
+a33be4c89e9eb6a282ac4ed7b14d3cd9fa8b90f3e493937c1c022faddfa678a5efb466b48f0951a1f880325f0234cfbd99c0c1c64d4a410eb4e64c8888a9f29c
diff --git a/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapPass.png.sha512 b/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapPass.png.sha512
index 19128806d8104609b9d73cec0932b48e882f8e40..f83f09d5228a056f684cdfb26530e468a7ce70c4 100644
--- a/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapPass.png.sha512
+++ b/Rendering/OpenGL2/Testing/Data/Baseline/TestShadowMapPass.png.sha512
@@ -1 +1 @@
-e9402f528869f5f3e6367b479e062aa1cfa63a781697f45fc89efd23cf6feb8a5e12a0b7ff1ebcd1b751515eca38945c710afc30ba225b847b3d7f851d270f06
+9412ed54080c7a972d786a269538a3dbd56a5aa070f2b35ba448dfd3cca211e7e4b4d196e07c8ff2d56ff4bb7b0855e5584758c09457d3d6f3c760ee47a4dded
diff --git a/Rendering/OpenGL2/vtkShadowMapBakerPass.cxx b/Rendering/OpenGL2/vtkShadowMapBakerPass.cxx
index 9ca97a4bd619c467fd427e86e8bc0c86f2b65eea..dfc4ec742e18ab2955e1d6a3b5a8a4229ad58676 100644
--- a/Rendering/OpenGL2/vtkShadowMapBakerPass.cxx
+++ b/Rendering/OpenGL2/vtkShadowMapBakerPass.cxx
@@ -10,6 +10,7 @@
#include "vtkLightCollection.h"
#include "vtkLightsPass.h"
#include "vtkMath.h"
+#include "vtkMatrix4x4.h"
#include "vtkNew.h"
#include "vtkObjectFactory.h"
#include "vtkOpaquePass.h"
@@ -453,6 +454,29 @@ void vtkShadowMapBakerPass::Render(const vtkRenderState* s)
first = false;
}
+ // Rendering a map for each light requires creating a camera from that
+ // light's perspective and doing an opaque rendering pass. That opaque
+ // rendering pass, in turn, updates the light transforms relative to that
+ // particular light camera. When it comes time to create a camera for
+ // a subsequent light, we need to restore it to its original light
+ // transform. We cache them here so we can restore them later.
+ std::map<vtkLight*, vtkSmartPointer<vtkMatrix4x4>> cachedLightTransforms;
+ lights->InitTraversal();
+ l = lights->GetNextItem();
+ while (l != nullptr)
+ {
+ if (!l->GetSwitch() || !this->LightCreatesShadow(l) || l->GetTransformMatrix() == nullptr)
+ {
+ cachedLightTransforms[l] = nullptr;
+ }
+ else
+ {
+ cachedLightTransforms[l] = vtkNew<vtkMatrix4x4>();
+ cachedLightTransforms[l]->DeepCopy(l->GetTransformMatrix());
+ }
+ l = lights->GetNextItem();
+ }
+
lights->InitTraversal();
l = lights->GetNextItem();
this->CurrentLightIndex = 0;
@@ -464,6 +488,19 @@ void vtkShadowMapBakerPass::Render(const vtkRenderState* s)
{
if (l->GetSwitch() && this->LightCreatesShadow(l))
{
+ // Restore the light's original matrix.
+ vtkMatrix4x4* cachedTransform = cachedLightTransforms.at(l);
+ if (cachedTransform != nullptr)
+ {
+ // Restore values without tweaking modified time.
+ vtkMatrix4x4::DeepCopy(*l->GetTransformMatrix()->Element, *cachedTransform->Element);
+ }
+ else
+ {
+ // This may be redundant; it is unlikely if the light didn't
+ // originally have a transform that it would pick one up.
+ l->SetTransformMatrix(nullptr);
+ }
vtkTextureObject* map = (*this->ShadowMaps)[this->CurrentLightIndex];
if (map == nullptr)
{