source/blender/draw/engines/workbench/shaders/infos/workbench_prepass_info.hh

@@ -40,8 +40,7 @@ GPU_SHADER_CREATE_INFO(workbench_next_mesh)
     .vertex_in(2, Type::VEC4, "ac")
     .vertex_in(3, Type::VEC2, "au")
     .vertex_source("workbench_prepass_vert.glsl")
-    .additional_info("draw_modelmat_new")
-    .additional_info("draw_resource_handle_new");
+    .additional_info("draw_modelmat_new_with_custom_id", "draw_resource_handle_new");
 
 GPU_SHADER_CREATE_INFO(workbench_next_curves)
     /* TODO Adding workbench_next_mesh to avoid shader compilation errors */

source/blender/draw/engines/workbench/shaders/workbench_prepass_vert.glsl

@@ -16,8 +16,12 @@ void main()
 
   normal_interp = normalize(normal_object_to_view(nor));
 
+  object_id = int(uint(resource_id) & 0xFFFFu) + 1;
+#ifdef WORKBENCH_NEXT
+  workbench_material_data_get(
+      int(drw_CustomID), ac.rgb, color_interp, alpha_interp, _roughness, metallic);
+#else
   workbench_material_data_get(
       resource_handle, ac.rgb, color_interp, alpha_interp, _roughness, metallic);
-
-  object_id = int(uint(resource_handle) & 0xFFFFu) + 1;
+#endif
 }

source/blender/draw/engines/workbench/workbench_engine.cc

@@ -68,6 +68,7 @@ class Instance {
                                  resolution,
                                  GPU_TEXTURE_USAGE_SHADER_READ | GPU_TEXTURE_USAGE_ATTACHMENT |
                                      GPU_TEXTURE_USAGE_MIP_SWIZZLE_VIEW);
+    resources.material_buf.clear();
 
     opaque_ps.sync(scene_state, resources);
     transparent_ps.sync(scene_state, resources);
@@ -202,12 +203,8 @@ class Instance {
             if (batches[i] == nullptr) {
               continue;
             }
-            /* TODO(fclem): This create a cull-able instance for each sub-object. This is done
-             * for simplicity to reduce complexity. But this increase the overhead per object.
-             * Instead, we should use an indirection buffer to the material buffer. */
-            ResourceHandle _handle = i == 0 ? handle : manager.resource_handle(ob_ref);
 
-            Material &mat = resources.material_buf.get_or_resize(_handle.resource_index());
+            Material mat;
 
             if (::Material *_mat = BKE_object_material_get_eval(ob_ref.object, i + 1)) {
               mat = Material(*_mat);
@@ -225,7 +222,7 @@ class Instance {
               get_material_image(ob_ref.object, i + 1, image, iuser, sampler_state);
             }
 
-            draw_mesh(ob_ref, mat, batches[i], _handle, image, sampler_state, iuser);
+            draw_mesh(ob_ref, mat, batches[i], handle, image, sampler_state, iuser);
           }
         }
       }
@@ -247,7 +244,7 @@ class Instance {
         }
 
         if (batch) {
-          Material &mat = resources.material_buf.get_or_resize(handle.resource_index());
+          Material mat;
 
           if (object_state.color_type == V3D_SHADING_OBJECT_COLOR) {
             mat = Material(*ob_ref.object);
@@ -291,9 +288,11 @@ class Instance {
                  ImageUser *iuser = nullptr)
   {
     const bool in_front = (ob_ref.object->dtx & OB_DRAW_IN_FRONT) != 0;
+    resources.material_buf.append(material);
+    int material_index = resources.material_buf.size() - 1;
 
     auto draw = [&](MeshPass &pass) {
-      pass.draw(ob_ref, batch, handle, image, sampler_state, iuser);
+      pass.draw(ob_ref, batch, handle, material_index, image, sampler_state, iuser);
     };
 
     if (scene_state.xray_mode || material.is_transparent()) {

source/blender/draw/engines/workbench/workbench_mesh_passes.cc

@@ -18,6 +18,7 @@ bool MeshPass::is_empty() const
 
 void MeshPass::init_pass(SceneResources &resources, DRWState state, int clip_planes)
 {
+  use_custom_ids = true;
   is_empty_ = true;
   PassMain::init();
   state_set(state, clip_planes);
@@ -57,6 +58,7 @@ void MeshPass::init_subpasses(ePipelineType pipeline,
 void MeshPass::draw(ObjectRef &ref,
                     GPUBatch *batch,
                     ResourceHandle handle,
+                    uint material_index,
                     ::Image *image /* = nullptr */,
                     eGPUSamplerState sampler_state /* = GPU_SAMPLER_DEFAULT */,
                     ImageUser *iuser /* = nullptr */)
@@ -95,11 +97,11 @@ void MeshPass::draw(ObjectRef &ref,
       };
 
       texture_subpass_map_.lookup_or_add_cb(TextureSubPassKey(texture, geometry_type), add_cb)
-          ->draw(batch, handle);
+          ->draw(batch, handle, material_index);
       return;
     }
   }
-  passes_[int(geometry_type)][int(eShaderType::MATERIAL)]->draw(batch, handle);
+  passes_[int(geometry_type)][int(eShaderType::MATERIAL)]->draw(batch, handle, material_index);
 }
 
 /** \} */

source/blender/draw/engines/workbench/workbench_private.hh

@@ -184,6 +184,7 @@ class MeshPass : public PassMain {
   void draw(ObjectRef &ref,
             GPUBatch *batch,
             ResourceHandle handle,
+            uint material_index,
             ::Image *image = nullptr,
             eGPUSamplerState sampler_state = eGPUSamplerState::GPU_SAMPLER_DEFAULT,
             ImageUser *iuser = nullptr);

source/blender/draw/intern/draw_command.cc

@@ -600,14 +600,13 @@ void DrawCommandBuf::bind(RecordingState &state,
 }
 
 void DrawMultiBuf::bind(RecordingState &state,
-                        Vector<Header, 0> &headers,
-                        Vector<Undetermined, 0> &commands,
+                        Vector<Header, 0> & /*headers*/,
+                        Vector<Undetermined, 0> & /*commands*/,
                         VisibilityBuf &visibility_buf,
                         int visibility_word_per_draw,
-                        int view_len)
+                        int view_len,
+                        bool use_custom_ids)
 {
-  UNUSED_VARS(headers, commands);
-
   GPU_debug_group_begin("DrawMultiBuf.bind");
 
   resource_id_count_ = 0u;
@@ -636,7 +635,7 @@ void DrawMultiBuf::bind(RecordingState &state,
   group_buf_.push_update();
   prototype_buf_.push_update();
   /* Allocate enough for the expansion pass. */
-  resource_id_buf_.get_or_resize(resource_id_count_);
+  resource_id_buf_.get_or_resize(resource_id_count_ * (use_custom_ids ? 2 : 1));
   /* Two command per group. */
   command_buf_.get_or_resize(group_count_ * 2);
 
@@ -646,6 +645,7 @@ void DrawMultiBuf::bind(RecordingState &state,
     GPU_shader_uniform_1i(shader, "prototype_len", prototype_count_);
     GPU_shader_uniform_1i(shader, "visibility_word_per_draw", visibility_word_per_draw);
     GPU_shader_uniform_1i(shader, "view_shift", log2_ceil_u(view_len));
+    GPU_shader_uniform_1b(shader, "use_custom_ids", use_custom_ids);
     GPU_storagebuf_bind(group_buf_, GPU_shader_get_ssbo_binding(shader, "group_buf"));
     GPU_storagebuf_bind(visibility_buf, GPU_shader_get_ssbo_binding(shader, "visibility_buf"));
     GPU_storagebuf_bind(prototype_buf_, GPU_shader_get_ssbo_binding(shader, "prototype_buf"));

source/blender/draw/intern/draw_command.hh

@@ -433,7 +433,8 @@ class DrawCommandBuf {
                    uint instance_len,
                    uint vertex_len,
                    uint vertex_first,
-                   ResourceHandle handle)
+                   ResourceHandle handle,
+                   uint /*custom_id*/)
   {
     vertex_first = vertex_first != -1 ? vertex_first : 0;
     instance_len = instance_len != -1 ? instance_len : 1;
@@ -533,7 +534,8 @@ class DrawMultiBuf {
                    uint instance_len,
                    uint vertex_len,
                    uint vertex_first,
-                   ResourceHandle handle)
+                   ResourceHandle handle,
+                   uint custom_id)
   {
     /* Custom draw-calls cannot be batched and will produce one group per draw. */
     const bool custom_group = ((vertex_first != 0 && vertex_first != -1) || vertex_len != -1);
@@ -555,6 +557,7 @@ class DrawMultiBuf {
 
     DrawPrototype &draw = prototype_buf_.get_or_resize(prototype_count_++);
     draw.resource_handle = handle.raw;
+    draw.custom_id = custom_id;
     draw.instance_len = instance_len;
     draw.group_id = group_id;
 
@@ -594,7 +597,8 @@ class DrawMultiBuf {
             Vector<Undetermined, 0> &commands,
             VisibilityBuf &visibility_buf,
             int visibility_word_per_draw,
-            int view_len);
+            int view_len,
+            bool use_custom_ids);
 };
 
 /** \} */

source/blender/draw/intern/draw_command_shared.hh

@@ -72,9 +72,10 @@ struct DrawPrototype {
   uint group_id;
   /* Resource handle associated with this call. Also reference visibility. */
   uint resource_handle;
+  /* Custom extra value to be used by the engines. */
+  uint custom_id;
   /* Number of instances. */
   uint instance_len;
-  uint _pad0;
 };
 BLI_STATIC_ASSERT_ALIGN(DrawPrototype, 16)
 

source/blender/draw/intern/draw_manager.cc

@@ -186,7 +186,8 @@ void Manager::submit(PassMain &pass, View &view)
                                pass.commands_,
                                view.get_visibility_buffer(),
                                view.visibility_word_per_draw(),
-                               view.view_len_);
+                               view.view_len_,
+                               pass.use_custom_ids);
 
   resource_bind();
 

source/blender/draw/intern/draw_pass.hh

@@ -135,6 +135,8 @@ class PassBase {
  public:
   const char *debug_name;
 
+  bool use_custom_ids;
+
   PassBase(const char *name,
            DrawCommandBufType &draw_command_buf,
            SubPassVector<PassBase<DrawCommandBufType>> &sub_passes,
@@ -142,7 +144,8 @@ class PassBase {
       : draw_commands_buf_(draw_command_buf),
         sub_passes_(sub_passes),
         shader_(shader),
-        debug_name(name){};
+        debug_name(name),
+        use_custom_ids(false){};
 
   /**
    * Reset the pass command pool.
@@ -224,13 +227,14 @@ class PassBase {
             uint instance_len = -1,
             uint vertex_len = -1,
             uint vertex_first = -1,
-            ResourceHandle handle = {0});
+            ResourceHandle handle = {0},
+            uint custom_id = 0);
 
   /**
    * Shorter version for the common case.
    * \note Implemented in derived class. Not a virtual function to avoid indirection.
    */
-  void draw(GPUBatch *batch, ResourceHandle handle);
+  void draw(GPUBatch *batch, ResourceHandle handle, uint custom_id = 0);
 
   /**
    * Record a procedural draw call. Geometry is **NOT** source from a GPUBatch.
@@ -240,7 +244,8 @@ class PassBase {
                        uint instance_len,
                        uint vertex_len,
                        uint vertex_first = -1,
-                       ResourceHandle handle = {0});
+                       ResourceHandle handle = {0},
+                       uint custom_id = 0);
 
   /**
    * Indirect variants.
@@ -654,20 +659,25 @@ template<class T> std::string PassBase<T>::serialize(std::string line_prefix) co
  * \{ */
 
 template<class T>
-inline void PassBase<T>::draw(
-    GPUBatch *batch, uint instance_len, uint vertex_len, uint vertex_first, ResourceHandle handle)
+inline void PassBase<T>::draw(GPUBatch *batch,
+                              uint instance_len,
+                              uint vertex_len,
+                              uint vertex_first,
+                              ResourceHandle handle,
+                              uint custom_id)
 {
   if (instance_len == 0 || vertex_len == 0) {
     return;
   }
   BLI_assert(shader_);
   draw_commands_buf_.append_draw(
-      headers_, commands_, batch, instance_len, vertex_len, vertex_first, handle);
+      headers_, commands_, batch, instance_len, vertex_len, vertex_first, handle, custom_id);
 }
 
-template<class T> inline void PassBase<T>::draw(GPUBatch *batch, ResourceHandle handle)
+template<class T>
+inline void PassBase<T>::draw(GPUBatch *batch, ResourceHandle handle, uint custom_id)
 {
-  this->draw(batch, -1, -1, -1, handle);
+  this->draw(batch, -1, -1, -1, handle, custom_id);
 }
 
 template<class T>
@@ -675,9 +685,11 @@ inline void PassBase<T>::draw_procedural(GPUPrimType primitive,
                                          uint instance_len,
                                          uint vertex_len,
                                          uint vertex_first,
-                                         ResourceHandle handle)
+                                         ResourceHandle handle,
+                                         uint custom_id)
 {
-  this->draw(procedural_batch_get(primitive), instance_len, vertex_len, vertex_first, handle);
+  this->draw(
+      procedural_batch_get(primitive), instance_len, vertex_len, vertex_first, handle, custom_id);
 }
 
 /** \} */

source/blender/draw/intern/shaders/draw_command_generate_comp.glsl

@@ -108,7 +108,14 @@ void main()
       uint view_index = i * 32u;
       while (word != 0u) {
         if ((word & 1u) != 0u) {
-          resource_id_buf[dst_index++] = view_index | (resource_index << view_shift);
+          if (use_custom_ids) {
+            resource_id_buf[dst_index * 2] = view_index | (resource_index << view_shift);
+            resource_id_buf[dst_index * 2 + 1] = proto.custom_id;
+          }
+          else {
+            resource_id_buf[dst_index] = view_index | (resource_index << view_shift);
+          }
+          dst_index++;
         }
         view_index++;
         word >>= 1u;
@@ -117,7 +124,13 @@ void main()
   }
   else {
     for (uint i = dst_index; i < dst_index + visible_instance_len; i++) {
-      resource_id_buf[i] = resource_index;
+      if (use_custom_ids) {
+        resource_id_buf[i * 2] = resource_index;
+        resource_id_buf[i * 2 + 1] = proto.custom_id;
+      }
+      else {
+        resource_id_buf[i] = resource_index;
+      }
     }
   }
 }

source/blender/draw/intern/shaders/draw_view_info.hh

@@ -189,6 +189,7 @@ GPU_SHADER_CREATE_INFO(draw_command_generate)
     .push_constant(Type::INT, "prototype_len")
     .push_constant(Type::INT, "visibility_word_per_draw")
     .push_constant(Type::INT, "view_shift")
+    .push_constant(Type::BOOL, "use_custom_ids")
     .compute_source("draw_command_generate_comp.glsl");
 
 /** \} */
@@ -200,9 +201,18 @@ GPU_SHADER_CREATE_INFO(draw_command_generate)
 
 GPU_SHADER_CREATE_INFO(draw_resource_id_new)
     .define("UNIFORM_RESOURCE_ID_NEW")
+    /* TODO (Miguel Pozo): This is an int for compatibility.
+     * It should become uint once the "Next" ports are complete. */
     .storage_buf(DRW_RESOURCE_ID_SLOT, Qualifier::READ, "int", "resource_id_buf[]")
     .define("drw_ResourceID", "resource_id_buf[gpu_BaseInstance + gl_InstanceID]");
 
+GPU_SHADER_CREATE_INFO(draw_resource_with_custom_id_new)
+    .define("UNIFORM_RESOURCE_ID_NEW")
+    .define("WITH_CUSTOM_IDS")
+    .storage_buf(DRW_RESOURCE_ID_SLOT, Qualifier::READ, "int2", "resource_id_buf[]")
+    .define("drw_ResourceID", "resource_id_buf[gpu_BaseInstance + gl_InstanceID].x")
+    .define("drw_CustomID", "resource_id_buf[gpu_BaseInstance + gl_InstanceID].y");
+
 /**
  * Workaround the lack of gl_BaseInstance by binding the resource_id_buf as vertex buf.
  */
@@ -210,6 +220,13 @@ GPU_SHADER_CREATE_INFO(draw_resource_id_fallback)
     .define("UNIFORM_RESOURCE_ID_NEW")
     .vertex_in(15, Type::INT, "drw_ResourceID");
 
+GPU_SHADER_CREATE_INFO(draw_resource_with_custom_id_fallback)
+    .define("UNIFORM_RESOURCE_ID_NEW")
+    .define("WITH_CUSTOM_IDS")
+    .vertex_in(15, Type::IVEC2, "vertex_in_drw_ResourceID")
+    .define("drw_ResourceID", "vertex_in_drw_ResourceID.x")
+    .define("drw_CustomID", "vertex_in_drw_ResourceID.y");
+
 /** TODO mask view id bits. */
 GPU_SHADER_CREATE_INFO(draw_resource_handle_new).define("resource_handle", "drw_ResourceID");
 
@@ -219,14 +236,19 @@ GPU_SHADER_CREATE_INFO(draw_resource_handle_new).define("resource_handle", "drw_
 /** \name Draw Object Resources
  * \{ */
 
-GPU_SHADER_CREATE_INFO(draw_modelmat_new)
+GPU_SHADER_CREATE_INFO(draw_modelmat_new_common)
     .typedef_source("draw_shader_shared.h")
     .storage_buf(DRW_OBJ_MAT_SLOT, Qualifier::READ, "ObjectMatrices", "drw_matrix_buf[]")
     .define("drw_ModelMatrixInverse", "drw_matrix_buf[resource_id].model_inverse")
     .define("drw_ModelMatrix", "drw_matrix_buf[resource_id].model")
     /* TODO For compatibility with old shaders. To be removed. */
     .define("ModelMatrixInverse", "drw_ModelMatrixInverse")
-    .define("ModelMatrix", "drw_ModelMatrix")
-    .additional_info("draw_resource_id_new");
+    .define("ModelMatrix", "drw_ModelMatrix");
+
+GPU_SHADER_CREATE_INFO(draw_modelmat_new)
+    .additional_info("draw_modelmat_new_common", "draw_resource_id_new");
+
+GPU_SHADER_CREATE_INFO(draw_modelmat_new_with_custom_id)
+    .additional_info("draw_modelmat_new_common", "draw_resource_with_custom_id_new");
 
 /** \} */

source/blender/gpu/intern/gpu_shader_create_info.cc

@@ -317,6 +317,7 @@ void gpu_shader_create_info_init()
   /* WORKAROUND: Replace the use of gpu_BaseInstance by an instance attribute. */
   if (GPU_shader_draw_parameters_support() == false) {
     draw_resource_id_new = draw_resource_id_fallback;
+    draw_resource_with_custom_id_new = draw_resource_with_custom_id_fallback;
   }
 
 #ifdef WITH_METAL_BACKEND

source/blender/gpu/opengl/gl_vertex_array.cc

@@ -121,12 +121,18 @@ void GLVertArray::update_bindings(const GLuint vao,
 
   if (batch->resource_id_buf) {
     const ShaderInput *input = interface->attr_get("drw_ResourceID");
+    int component_len = 1;
+    if (input == nullptr) {
+      /* Uses Custom IDs */
+      input = interface->attr_get("vertex_in_drw_ResourceID_");
+      component_len = 2;
+    }
     if (input) {
       dynamic_cast<GLStorageBuf *>(unwrap(batch->resource_id_buf))->bind_as(GL_ARRAY_BUFFER);
       glEnableVertexAttribArray(input->location);
       glVertexAttribDivisor(input->location, 1);
       glVertexAttribIPointer(
-          input->location, 1, to_gl(GPU_COMP_I32), sizeof(uint32_t), (GLvoid *)nullptr);
+          input->location, component_len, to_gl(GPU_COMP_I32), 0, (GLvoid *)nullptr);
       attr_mask &= ~(1 << input->location);
     }
   }