feat(architecture): support alpha as coverage

ISceneGraphRepoDp->bsdfMaterialRepo add getAlphaCutoff;
fix get_hit_shading_data.glsl;
fix UpdatePathTracingCPJobEntity->_buildAndSetBSDFMaterialBufferData;

Author: yyc-git

src/construct/application_layer/scene/BSDFMaterialApService.re

@@ -52,6 +52,10 @@ let getSpecularMapImageId = material => {
   OperateBSDFMaterialDoService.getSpecularMapImageId(material);
 };
 
+let getAlphaCutoff = material => {
+  OperateBSDFMaterialDoService.getAlphaCutoff(material);
+};
+
 let isSame = (material1, material2) => {
   OperateBSDFMaterialDoService.isSame(material1, material2);
 };

src/construct/domain_layer/dependency/interface/engine/ISceneGraphRepoDp.re

@@ -63,6 +63,8 @@ type bsdfMaterialRepo = {
   getNormalMapImageId: bsdfMaterial => option(ImageRepoType.id),
   getTransmissionMapImageId: bsdfMaterial => option(ImageRepoType.id),
   getSpecularMapImageId: bsdfMaterial => option(ImageRepoType.id),
+  // isUseAlphaBlend: bsdfMaterial => bool,
+  getAlphaCutoff: bsdfMaterial => float,
   isSame: (bsdfMaterial, bsdfMaterial) => bool,
   getId: bsdfMaterial => int,
 };

src/construct/domain_layer/domain/scene/scene_graph/service/bsdf_material/OperateBSDFMaterialDoService.re

@@ -79,6 +79,12 @@ let getSpecularMapImageId = material =>
   )
   ->OptionSt.map(ImageIdVO.create);
 
+let getAlphaCutoff = material =>
+  DpContainer.unsafeGetBSDFMaterialRepoDp().getAlphaCutoff(
+    material->BSDFMaterialEntity.value,
+  )
+  ->AlphaCutoffVO.create;
+
 let isSame = (material1, material2) => {
   DpContainer.unsafeGetBSDFMaterialRepoDp().isSame(
     material1->BSDFMaterialEntity.value,

src/construct/domain_layer/domain/scene/scene_graph/value_object/AlphaCutoffVO.re

@@ -0,0 +1,9 @@
+type t =
+  | AlphaCutoff(float);
+
+let create = value => AlphaCutoff(value);
+
+let value = alphaCutoff =>
+  switch (alphaCutoff) {
+  | AlphaCutoff(value) => value
+  };

src/construct/external_layer/api/domain/BSDFMaterialRunAPI.re

@@ -50,6 +50,10 @@ let getSpecularMapImageId = material => {
   BSDFMaterialApService.getSpecularMapImageId(material);
 };
 
+let getAlphaCutoff = material => {
+  BSDFMaterialApService.getAlphaCutoff(material);
+};
+
 let isSame = (material1, material2) => {
   BSDFMaterialApService.isSame(material1, material2);
 };

src/run/domain_layer/domain/pipeline/pipeline/entity/jobs/update/UpdatePathTracingCPJobEntity.re

@@ -480,6 +480,9 @@ let _buildAndSetBSDFMaterialBufferData = (device, allRenderBSDFMaterials) => {
         let diffuse =
           BSDFMaterialRunAPI.getDiffuseColor(bsdfMaterial)
           ->DiffuseVO.getPrimitiveValue;
+        let alphaCutoff =
+          BSDFMaterialRunAPI.getAlphaCutoff(bsdfMaterial)
+          ->AlphaCutoffVO.value;
         let specularColor =
           BSDFMaterialRunAPI.getSpecularColor(bsdfMaterial)
           ->SpecularColorVO.getPrimitiveValue;
@@ -530,6 +533,11 @@ let _buildAndSetBSDFMaterialBufferData = (device, allRenderBSDFMaterials) => {
             ) => {
             ListResult.mergeResults([
               TypeArrayCPRepoUtils.setFloat3(offset + 0, diffuse, bufferData),
+              TypeArrayCPRepoUtils.setFloat1(
+                offset + 3,
+                alphaCutoff,
+                bufferData,
+              ),
               TypeArrayCPRepoUtils.setFloat3(
                 offset + 4,
                 specularColor,

src/run/domain_layer/domain/shader/ray_tracing/get_hit_shading_data.glsl

@@ -25,7 +25,7 @@ struct PointIndexData {
 };
 
 struct BSDFMaterial {
-  vec4 diffuse;
+  vec4 diffuseAndAlphaCutoff;
 
   vec4 specularColor;
 
@@ -140,6 +140,10 @@ struct HitShadingData {
   float materialIOR;
 };
 
+bool _isUseAlphaAsCoverageInsteadOfTransmission(float alphaCutoff) {
+  return alphaCutoff > 0.0;
+}
+
 HitShadingData getHitShadingData(uint instanceIndex, uint primitiveIndex) {
   InstanceData instanceData = _getInstanceData(instanceIndex);
 
@@ -184,15 +188,22 @@ HitShadingData getHitShadingData(uint instanceIndex, uint primitiveIndex) {
 
   HitShadingData data;
 
+  float alphaCutoff = mat.diffuseAndAlphaCutoff.w;
+  float alpha = 1.0;
+
   if (_hasMap(diffuseMapLayerIndex)) {
+    vec4 diffuseMapData =
+        texture(sampler2DArray(textureArray, textureSampler),
+                vec3(uv * mat.diffuseMapScale, diffuseMapLayerIndex));
+
     data.materialDiffuse =
-        convertSRGBToLinear(
-            texture(sampler2DArray(textureArray, textureSampler),
-                    vec3(uv * mat.diffuseMapScale, diffuseMapLayerIndex))
-                .rgb) +
-        vec3(mat.diffuse);
+        convertSRGBToLinear(diffuseMapData.rgb) + mat.diffuseAndAlphaCutoff.xyz;
+
+    alpha = diffuseMapData.a;
   } else {
-    data.materialDiffuse = vec3(mat.diffuse);
+    data.materialDiffuse = mat.diffuseAndAlphaCutoff.xyz;
+
+    alpha = 1.0;
   }
 
   if (_hasMap(specularMapLayerIndex)) {
@@ -245,18 +256,24 @@ HitShadingData getHitShadingData(uint instanceIndex, uint primitiveIndex) {
     data.materialRoughness = mat.roughness;
   }
 
-  if (_hasMap(transmissionMapLayerIndex)) {
-    data.materialTransmission =
-        texture(sampler2DArray(textureArray, textureSampler),
-                vec3(uv * mat.transmissionMapScale, transmissionMapLayerIndex))
-            .r *
-        mat.transmission;
+  if (_isUseAlphaAsCoverageInsteadOfTransmission(alphaCutoff)) {
+    data.materialTransmission = alpha >= alphaCutoff ? 0.0 : 1.0 - alpha;
+    data.materialIOR = 1.0;
   } else {
-    data.materialTransmission = mat.transmission;
+    if (_hasMap(transmissionMapLayerIndex)) {
+      data.materialTransmission =
+          texture(
+              sampler2DArray(textureArray, textureSampler),
+              vec3(uv * mat.transmissionMapScale, transmissionMapLayerIndex))
+              .r *
+          mat.transmission;
+    } else {
+      data.materialTransmission = mat.transmission;
+    }
+
+    data.materialIOR = mat.ior;
   }
 
-  data.materialIOR = mat.ior;
-
   const vec3 p0 = v0.position.xyz, p1 = v1.position.xyz, p2 = v2.position.xyz;
 
   vec3 localPos = _blerp(attribs.xy, p0.xyz, p1.xyz, p2.xyz);

src/run/external_layer/api/dependency/SceneGraphRepoDpCPAPI.re

@@ -38,6 +38,7 @@ let set =
     getNormalMapImageId,
     getTransmissionMapImageId,
     getSpecularMapImageId,
+    getAlphaCutoff,
     isSame: isSameBSDFMaterial,
     getId: getBSDFMaterialId,
   }: SceneGraphRepoDpCPType.bsdfMaterialRepo = bsdfMaterialRepo;
@@ -130,6 +131,7 @@ let set =
         getSpecularMapImageId: bsdfMaterial => {
           getSpecularMapImageId(bsdfMaterial)->OptionSt.fromNullable;
         },
+        getAlphaCutoff,
       },
       geometryRepo: {
         isSame: isSameGeometry,

src/run/external_layer/api/dependency/vo/SceneGraphRepoDpCPType.re

@@ -47,6 +47,7 @@ type bsdfMaterialRepo = {
   getNormalMapImageId: bsdfMaterial => Js.Nullable.t(ImageRepoType.id),
   getTransmissionMapImageId: bsdfMaterial => Js.Nullable.t(ImageRepoType.id),
   getSpecularMapImageId: bsdfMaterial => Js.Nullable.t(ImageRepoType.id),
+  getAlphaCutoff: bsdfMaterial => float,
   isSame: (bsdfMaterial, bsdfMaterial) => bool,
   getId: bsdfMaterial => int,
 };

test/construct/tool/SceneGraphRepoDependencyTool.re

@@ -139,6 +139,7 @@ let buildBSDFMaterialRepo =
       ~getMetalness=createEmptyStub(refJsObjToSandbox(sandbox^)),
       ~getTransmission=createEmptyStub(refJsObjToSandbox(sandbox^)),
       ~getIOR=createEmptyStub(refJsObjToSandbox(sandbox^)),
+      ~getAlphaCutoff=createEmptyStub(refJsObjToSandbox(sandbox^)),
       ~getDiffuseMapImageId=createEmptyStub(refJsObjToSandbox(sandbox^)),
       ~getChannelRoughnessMetallicMapImageId=createEmptyStub(
                                                refJsObjToSandbox(sandbox^),
@@ -167,6 +168,7 @@ let buildBSDFMaterialRepo =
   getNormalMapImageId,
   getTransmissionMapImageId,
   getSpecularMapImageId,
+  getAlphaCutoff,
 };
 
 let buildGeometryRepo =

test/run/integration/updatePathTracingCPJob_test.re

@@ -1272,7 +1272,7 @@ let _ =
           )
         });
         testPromise(
-          "set each render bsdfMaterial's diffuse, specular, specularColor, roughness, metalness, transmission, ior, diffuseMapLayerIndex, channelRoughnessMetallicMapLayerIndex, emissionMapLayerIndex, normalMapLayerIndex, transmissionMapLayerIndex, specularMapLayerIndex, diffuseMapScale, channelRoughnessMetallicScaleScale, emissionMapScale, normalMapScale, transmissionMapScale, specularMapScale to buffer data",
+          "set each render bsdfMaterial's diffuse, alphaCutoff, specular, specularColor, roughness, metalness, transmission, ior, diffuseMapLayerIndex, channelRoughnessMetallicMapLayerIndex, emissionMapLayerIndex, normalMapLayerIndex, transmissionMapLayerIndex, specularMapLayerIndex, diffuseMapScale, channelRoughnessMetallicScaleScale, emissionMapScale, normalMapScale, transmissionMapScale, specularMapScale to buffer data",
           () => {
             open ImageRepoType;
             let (
@@ -1333,7 +1333,7 @@ let _ =
                        0.,
                        1.,
                        0.,
-                       0.,
+                       0.5,
                        0.5,
                        1.,
                        0.,

test/run/tool/BSDFMaterialCPTool.re

@@ -6,6 +6,8 @@ let buildRepoWithTwoMaterialsAndMapData = sandbox => {
 
   let diffuseColor1 = (1., 0., 0.);
   let diffuseColor2 = (0., 1., 0.);
+  let alphaCutoff1 = 0.0;
+  let alphaCutoff2 = 0.5;
   let specular1 = 0.5;
   let specular2 = 1.0;
   let specularColor1 = (0.5, 0., 0.);
@@ -92,6 +94,12 @@ let buildRepoWithTwoMaterialsAndMapData = sandbox => {
             | material when material == material1 => diffuseColor1
             | material when material == material2 => diffuseColor2
             },
+        ~getAlphaCutoff=
+          material =>
+            switch (material) {
+            | material when material == material1 => alphaCutoff1
+            | material when material == material2 => alphaCutoff2
+            },
         ~getSpecular=
           material =>
             switch (material) {