Fix cut-out transparency in Principled material

apps/common/ospray_testing/builders/test_pt_principled_tex.cpp

@@ -141,9 +141,22 @@ std::vector<cpp::Material> PtPrincipledTex::buildMaterials(
     setTexture<float>(materials.back(), "backlight", texR, 2.f);
   }
 
-  materials.push_back(cpp::Material("principled"));
-  materials.back().setParam("baseColor", vec3f(1.f, 0.8f, 0.7f));
-  setTexture<vec3f>(materials.back(), "emissiveColor", texRGBA);
+  {
+    // emissive
+    materials.push_back(cpp::Material("principled"));
+    materials.back().setParam("baseColor", vec3f(1.f, 0.8f, 0.7f));
+    setTexture<vec3f>(materials.back(), "emissiveColor", texRGBA);
+
+    // transparency
+    materials.push_back(cpp::Material("principled"));
+    materials.back().setParam("baseColor", vec3f(0.860f, 0.0258f, 0.0536f));
+    setTexture<vec3f>(materials.back(), "baseColor", texRGBA);
+
+    // opacity
+    materials.push_back(cpp::Material("principled"));
+    materials.back().setParam("baseColor", vec3f(0.860f, 0.0258f, 0.0536f));
+    setTexture<float>(materials.back(), "opacity", texR);
+  }
 
   return materials;
 }

apps/common/ospray_testing/builders/test_pt_tex.h

@@ -54,7 +54,7 @@ static cpp::Texture makeCheckerboardTextureRGBA8()
   index_sequence_2D idx(vec2i(width, height));
   for (auto i : idx) {
     uint8_t v = ((i.x & 2) ^ (i.y & 2)) * 255;
-    dbyte[idx.flatten(i)] = vec4uc(v, v, v, 255);
+    dbyte[idx.flatten(i)] = vec4uc(v, v, v, 128 + v / 2);
   }
 
   // Create texture object
@@ -202,8 +202,10 @@ inline cpp::World PtTex::buildWorld() const
   cpp::Texture texRGBA = makeCheckerboardTextureRGBA8();
 
   std::vector<cpp::Material> materials = buildMaterials(texR, texRGBA);
-  const int dimCount = sqrtf(materials.size());
-  const int dimSize = dimCount - 1;
+  size_t dimCount = sqrtf(materials.size());
+  if (dimCount * dimCount < materials.size())
+    dimCount++;
+  const size_t dimSize = dimCount - 1;
 
   cpp::Geometry sphereGeometry = makeSphereMesh(25, 50);
 
@@ -212,10 +214,12 @@ inline cpp::World PtTex::buildWorld() const
   box3f bbox(empty);
   index_sequence_2D numSpheres(dimCount);
   for (auto i : numSpheres) {
+    const auto idx = numSpheres.flatten(i);
+    if (idx >= materials.size())
+      break;
     // Construct GeometricModel for each instance
     cpp::GeometricModel model(sphereGeometry);
-    model.setParam(
-        "material", cpp::CopiedData(materials[numSpheres.flatten(i)]));
+    model.setParam("material", cpp::CopiedData(materials[idx]));
     model.commit();
 
     // Construct Group for each instance

modules/cpu/render/materials/Principled.ispc

@@ -415,7 +415,8 @@ SYCL_EXTERNAL const varying BSDF *uniform Principled_getBSDF(
   }
 
   // cut-out transparency
-  if (1.f - self->opacity > EPS) {
+  if (1.f - self->opacity > EPS || valid(self->opacityMap)
+      || hasAlpha(self->baseColorMap)) {
     const float transparency = 1.f - opacity;
     Transmission_Constructor(
         &bsdf->transmission, frame, make_vec3f(transparency));

test_image_data/baseline/AVX2/FromOsprayTesting_TestScenesPtMaterials_test_scenes_14.png.md5

@@ -1 +1 @@
-87a2eff0c9ec4aeb40263168aa2c1d81
+41ddb4e5febf2144fec35803a200103e

test_image_data/baseline/AVX2/FromOsprayTesting_TestScenesPtMaterials_test_scenes_5.png.md5

@@ -1 +1 @@
-b1eae3b5638b160aa9ab8d9fc1342ea2
+c268dbb557f08c8184fdf69bfe51d4e1

test_image_data/baseline/AVX512SKX/FromOsprayTesting_TestScenesPtMaterials_test_scenes_14.png.md5

@@ -1 +1 @@
-87a2eff0c9ec4aeb40263168aa2c1d81
+41ddb4e5febf2144fec35803a200103e

test_image_data/baseline/AVX512SKX/FromOsprayTesting_TestScenesPtMaterials_test_scenes_5.png.md5

@@ -1 +1 @@
-b1eae3b5638b160aa9ab8d9fc1342ea2
+c268dbb557f08c8184fdf69bfe51d4e1