Enable backface culling by default.

Disable only for geom types that need it (planes and triangles).

PiperOrigin-RevId: 914211570
Change-Id: Id95e32924122789111f561d922110128b3f56c77

src/experimental/filament/assets/pbr.mat

@@ -15,7 +15,6 @@
 material {
     name : pbr,
     shadingModel : lit,
-    culling: none,
     flipUV: false,
     parameters : [
         { type : sampler2d, name : BaseColor },

src/experimental/filament/assets/pbr_packed.mat

@@ -15,7 +15,6 @@
 material {
     name : pbr_packed,
     shadingModel : lit,
-    culling: none,
     flipUV: false,
     parameters : [
         { type : sampler2d, name : BaseColor },

src/experimental/filament/assets/phong_2d.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_2d,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     parameters : [
         { type : float4, name : BaseColorFactor },

src/experimental/filament/assets/phong_2d_fade.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_2d_fade,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     blending: fade,
     parameters : [

src/experimental/filament/assets/phong_2d_reflect.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_2d_reflect,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     parameters : [
         { type : float4, name : BaseColorFactor },

src/experimental/filament/assets/phong_2d_uv.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_2d_uv,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     parameters : [
         { type : float4, name : BaseColorFactor },

src/experimental/filament/assets/phong_2d_uv_fade.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_2d_uv_fade,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     blending: fade,
     parameters : [

src/experimental/filament/assets/phong_2d_uv_reflect.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_2d_uv_reflect,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     parameters : [
         { type : float4, name : BaseColorFactor },

src/experimental/filament/assets/phong_color.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_color,
     shadingModel : specularGlossiness,
-    culling: none,
     parameters : [
         { type : float4, name : BaseColorFactor },
         { type : float, name : SpecularFactor },

src/experimental/filament/assets/phong_color_fade.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_color_fade,
     shadingModel : specularGlossiness,
-    culling: none,
     blending: fade,
     parameters : [
         { type : float4, name : BaseColorFactor },

src/experimental/filament/assets/phong_color_reflect.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_color_reflect,
     shadingModel : specularGlossiness,
-    culling: none,
     parameters : [
         { type : float4, name : BaseColorFactor },
         { type : float, name : SpecularFactor },

src/experimental/filament/assets/phong_cube.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_cube,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     parameters : [
         { type : float4, name : BaseColorFactor },

src/experimental/filament/assets/phong_cube_fade.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_cube_fade,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     blending: fade,
     parameters : [

src/experimental/filament/assets/phong_cube_reflect.mat

@@ -15,7 +15,6 @@
 material {
     name : phong_cube_reflect,
     shadingModel : specularGlossiness,
-    culling : none,
     flipUV : false,
     parameters : [
         { type : float4, name : BaseColorFactor },

src/experimental/filament/assets/unlit_decor.mat

@@ -15,7 +15,6 @@
 material {
     name : unlit_decor,
     shadingModel : unlit,
-    culling: none,
     parameters : [
         { type : float4, name : BaseColorFactor }
     ]

src/experimental/filament/assets/unlit_depth.mat

@@ -16,7 +16,6 @@ material {
     name : unlit_depth,
     shadingModel : unlit,
     blending : opaque,
-    culling: none,
     depthWrite: true
 }
 

src/experimental/filament/assets/unlit_segmentation.mat

@@ -15,7 +15,6 @@
 material {
     name : unlit_segmentation,
     shadingModel : unlit,
-    culling: none,
     parameters : [
         { type : float4, name : SegmentationColor }
     ]

src/experimental/filament/filament/renderable.cc

@@ -77,6 +77,11 @@ void Renderable::SetMesh(const Mesh* mesh, int elem_offset, int elem_count) {
   if (mesh == nullptr) {
     mju_error("Cannot set mesh to nullptr.");
   }
+
+  // We use MESH, even though it could be any mesh-like geom type, e.g.
+  // heightfields, flex, skin, sdf, etc.
+  geom_type_ = mjGEOM_MESH;
+
   filament::VertexBuffer* vertex_buffer = mesh->GetFilamentVertexBuffer();
   if (vertex_buffer == nullptr) {
     mju_error("Invalid (null) vertex buffer.");
@@ -234,6 +239,10 @@ void Renderable::AssignMaterial(mjrDrawMode mode,
   }
   if (material) {
     instances_[index] = material->createInstance();
+    if (geom_type_ == mjGEOM_PLANE || geom_type_ == mjGEOM_TRIANGLE) {
+      instances_[index]->setCullingMode(
+          filament::MaterialInstance::CullingMode::NONE);
+    }
   }
 }
 
@@ -407,6 +416,7 @@ ObjectManager::MaterialType Renderable::GetColorMaterialType() const {
 
 void Renderable::SetGeomMesh(mjtGeom type, int nstack, int nslice, int nquad) {
   Builtins* builtins = object_mgr_->GetBuiltins(nstack, nslice, nquad);
+  geom_type_ = type;
 
   switch (type) {
     case mjGEOM_PLANE:

src/experimental/filament/filament/renderable.h

@@ -130,6 +130,7 @@ class Renderable : public mjrRenderable {
   ObjectManager* object_mgr_;
   mjrRenderableParams params_;
   filament::MaterialInstance* instances_[mjNUM_DRAW_MODES] = {nullptr};
+  mjtGeom geom_type_ = mjGEOM_NONE;
   mjrMaterial material_;
   mjrDrawMode draw_mode_ = mjDRAW_MODE_COLOR;
   filament::Scene* assigned_scene_ = nullptr;

src/experimental/filament/filament/scene_view.cc

@@ -141,6 +141,7 @@ SceneView::SceneView(FilamentContext* ctx, const mjrSceneParams& params)
   reflect_view_->setCamera(reflect_camera_);
   reflect_view_->setShadowingEnabled(false);
   reflect_view_->setPostProcessingEnabled(false);
+  reflect_view_->setFrontFaceWindingInverted(true);
   reflect_view_->setVisibleLayers(0xff, params.reflection_layer_mask);
 
   // Disable post processing for the depth and segmentation views to preserve