Option for software skinning in MeshInstance

Option in MeshInstance to enable software skinning, in order to test
against the current USE_SKELETON_SOFTWARE path which causes problems
with bad performance.

Co-authored-by: lawnjelly <[email protected]>

doc/classes/MeshInstance.xml

@@ -30,6 +30,15 @@
 				This helper creates a [StaticBody] child node with a [ConcavePolygonShape] collision shape calculated from the mesh geometry. It's mainly used for testing.
 			</description>
 		</method>
+		<method name="get_active_material" qualifiers="const">
+			<return type="Material">
+			</return>
+			<argument index="0" name="surface" type="int">
+			</argument>
+			<description>
+				Returns the [Material] that will be used by the [Mesh] when drawing. This can return the [member GeometryInstance.material_override], the surface override [Material] defined in this [MeshInstance], or the surface [Material] defined in the [Mesh]. For example, if [member GeometryInstance.material_override] is used, all surfaces will return the override material.
+			</description>
+		</method>
 		<method name="get_surface_material" qualifiers="const">
 			<return type="Material">
 			</return>
@@ -68,6 +77,10 @@
 		<member name="skin" type="Skin" setter="set_skin" getter="get_skin">
 			Sets the skin to be used by this instance.
 		</member>
+		<member name="software_skinning_transform_normals" type="bool" setter="set_software_skinning_transform_normals" getter="is_software_skinning_transform_normals_enabled" default="true">
+			If [code]true[/code], normals are transformed when software skinning is used. Set to [code]false[/code] when normals are not needed for better performance.
+			See [member ProjectSettings.rendering/quality/skinning/software_skinning_fallback] for details about how software skinning is enabled.
+		</member>
 	</members>
 	<constants>
 	</constants>

doc/classes/ProjectSettings.xml

@@ -1177,6 +1177,16 @@
 		<member name="rendering/quality/shadows/filter_mode.mobile" type="int" setter="" getter="" default="0">
 			Lower-end override for [member rendering/quality/shadows/filter_mode] on mobile devices, due to performance concerns or driver support.
 		</member>
+		<member name="rendering/quality/skinning/software_skinning_fallback" type="bool" setter="" getter="" default="true">
+			Allows [MeshInstance] to perform skinning on the CPU when the hardware doesn't support the default GPU skinning process with GLES2.
+			If [code]false[/code], an alternative skinning process on the GPU is used in this case (slower in most cases).
+			See also [member rendering/quality/skinning/force_software_skinning].
+			[b]Note:[/b] When the software skinning fallback is triggered, custom vertex shaders will behave in a different way, because the bone transform will be already applied to the modelview matrix.
+		</member>
+		<member name="rendering/quality/skinning/force_software_skinning" type="bool" setter="" getter="" default="false">
+			Forces [MeshInstance] to always perform skinning on the CPU (applies to both GLES2 and GLES3).
+			See also [member rendering/quality/skinning/software_skinning_fallback].
+		</member>
 		<member name="rendering/quality/spatial_partitioning/render_tree_balance" type="float" setter="" getter="" default="0.17">
 			The rendering octree balance can be changed to favor smaller ([code]0[/code]), or larger ([code]1[/code]) branches.
 			Larger branches can increase performance significantly in some projects.

doc/classes/VisualServer.xml

@@ -1679,7 +1679,8 @@
 			<argument index="0" name="feature" type="String">
 			</argument>
 			<description>
-				Returns [code]true[/code] if the OS supports a certain feature. Features might be [code]s3tc[/code], [code]etc[/code], [code]etc2[/code] and [code]pvrtc[/code].
+				Returns [code]true[/code] if the OS supports a certain feature. Features might be [code]s3tc[/code], [code]etc[/code], [code]etc2[/code], [code]pvrtc[/code] and [code]skinning_fallback[/code].
+				When rendering with GLES2, returns [code]true[/code] with [code]skinning_fallback[/code] in case the hardware doesn't support the default GPU skinning process.
 			</description>
 		</method>
 		<method name="immediate_begin">

drivers/gles2/rasterizer_storage_gles2.cpp

@@ -1473,6 +1473,8 @@ void RasterizerStorageGLES2::_update_shader(Shader *p_shader) const {
 			p_shader->spatial.uses_screen_texture = false;
 			p_shader->spatial.uses_depth_texture = false;
 			p_shader->spatial.uses_vertex = false;
+			p_shader->spatial.uses_tangent = false;
+			p_shader->spatial.uses_ensure_correct_normals = false;
 			p_shader->spatial.writes_modelview_or_projection = false;
 			p_shader->spatial.uses_world_coordinates = false;
 
@@ -1497,6 +1499,8 @@ void RasterizerStorageGLES2::_update_shader(Shader *p_shader) const {
 
 			shaders.actions_scene.render_mode_flags["world_vertex_coords"] = &p_shader->spatial.uses_world_coordinates;
 
+			shaders.actions_scene.render_mode_flags["ensure_correct_normals"] = &p_shader->spatial.uses_ensure_correct_normals;
+
 			shaders.actions_scene.usage_flag_pointers["ALPHA"] = &p_shader->spatial.uses_alpha;
 			shaders.actions_scene.usage_flag_pointers["ALPHA_SCISSOR"] = &p_shader->spatial.uses_alpha_scissor;
 
@@ -1506,6 +1510,11 @@ void RasterizerStorageGLES2::_update_shader(Shader *p_shader) const {
 			shaders.actions_scene.usage_flag_pointers["DEPTH_TEXTURE"] = &p_shader->spatial.uses_depth_texture;
 			shaders.actions_scene.usage_flag_pointers["TIME"] = &p_shader->spatial.uses_time;
 
+			// Use of any of these BUILTINS indicate the need for transformed tangents.
+			// This is needed to know when to transform tangents in software skinning.
+			shaders.actions_scene.usage_flag_pointers["TANGENT"] = &p_shader->spatial.uses_tangent;
+			shaders.actions_scene.usage_flag_pointers["NORMALMAP"] = &p_shader->spatial.uses_tangent;
+
 			shaders.actions_scene.write_flag_pointers["MODELVIEW_MATRIX"] = &p_shader->spatial.writes_modelview_or_projection;
 			shaders.actions_scene.write_flag_pointers["PROJECTION_MATRIX"] = &p_shader->spatial.writes_modelview_or_projection;
 			shaders.actions_scene.write_flag_pointers["VERTEX"] = &p_shader->spatial.uses_vertex;
@@ -1897,6 +1906,36 @@ bool RasterizerStorageGLES2::material_casts_shadows(RID p_material) {
 	return casts_shadows;
 }
 
+bool RasterizerStorageGLES2::material_uses_tangents(RID p_material) {
+	Material *material = material_owner.get(p_material);
+	ERR_FAIL_COND_V(!material, false);
+
+	if (!material->shader) {
+		return false;
+	}
+
+	if (material->shader->dirty_list.in_list()) {
+		_update_shader(material->shader);
+	}
+
+	return material->shader->spatial.uses_tangent;
+}
+
+bool RasterizerStorageGLES2::material_uses_ensure_correct_normals(RID p_material) {
+	Material *material = material_owner.get(p_material);
+	ERR_FAIL_COND_V(!material, false);
+
+	if (!material->shader) {
+		return false;
+	}
+
+	if (material->shader->dirty_list.in_list()) {
+		_update_shader(material->shader);
+	}
+
+	return material->shader->spatial.uses_ensure_correct_normals;
+}
+
 void RasterizerStorageGLES2::material_add_instance_owner(RID p_material, RasterizerScene::InstanceBase *p_instance) {
 
 	Material *material = material_owner.getornull(p_material);
@@ -5769,6 +5808,9 @@ bool RasterizerStorageGLES2::has_os_feature(const String &p_feature) const {
 	if (p_feature == "etc")
 		return config.etc1_supported;
 
+	if (p_feature == "skinning_fallback")
+		return config.use_skeleton_software;
+
 	return false;
 }
 

drivers/gles2/rasterizer_storage_gles2.h

@@ -503,6 +503,8 @@ class RasterizerStorageGLES2 : public RasterizerStorage {
 			bool uses_screen_texture;
 			bool uses_depth_texture;
 			bool uses_time;
+			bool uses_tangent;
+			bool uses_ensure_correct_normals;
 			bool writes_modelview_or_projection;
 			bool uses_vertex_lighting;
 			bool uses_world_coordinates;
@@ -607,6 +609,8 @@ class RasterizerStorageGLES2 : public RasterizerStorage {
 
 	virtual bool material_is_animated(RID p_material);
 	virtual bool material_casts_shadows(RID p_material);
+	virtual bool material_uses_tangents(RID p_material);
+	virtual bool material_uses_ensure_correct_normals(RID p_material);
 
 	virtual void material_add_instance_owner(RID p_material, RasterizerScene::InstanceBase *p_instance);
 	virtual void material_remove_instance_owner(RID p_material, RasterizerScene::InstanceBase *p_instance);

drivers/gles3/rasterizer_storage_gles3.cpp

@@ -2342,6 +2342,8 @@ void RasterizerStorageGLES3::_update_shader(Shader *p_shader) const {
 			p_shader->spatial.uses_screen_texture = false;
 			p_shader->spatial.uses_depth_texture = false;
 			p_shader->spatial.uses_vertex = false;
+			p_shader->spatial.uses_tangent = false;
+			p_shader->spatial.uses_ensure_correct_normals = false;
 			p_shader->spatial.writes_modelview_or_projection = false;
 			p_shader->spatial.uses_world_coordinates = false;
 
@@ -2366,6 +2368,8 @@ void RasterizerStorageGLES3::_update_shader(Shader *p_shader) const {
 
 			shaders.actions_scene.render_mode_flags["world_vertex_coords"] = &p_shader->spatial.uses_world_coordinates;
 
+			shaders.actions_scene.render_mode_flags["ensure_correct_normals"] = &p_shader->spatial.uses_ensure_correct_normals;
+
 			shaders.actions_scene.usage_flag_pointers["ALPHA"] = &p_shader->spatial.uses_alpha;
 			shaders.actions_scene.usage_flag_pointers["ALPHA_SCISSOR"] = &p_shader->spatial.uses_alpha_scissor;
 
@@ -2375,6 +2379,11 @@ void RasterizerStorageGLES3::_update_shader(Shader *p_shader) const {
 			shaders.actions_scene.usage_flag_pointers["DEPTH_TEXTURE"] = &p_shader->spatial.uses_depth_texture;
 			shaders.actions_scene.usage_flag_pointers["TIME"] = &p_shader->spatial.uses_time;
 
+			// Use of any of these BUILTINS indicate the need for transformed tangents.
+			// This is needed to know when to transform tangents in software skinning.
+			shaders.actions_scene.usage_flag_pointers["TANGENT"] = &p_shader->spatial.uses_tangent;
+			shaders.actions_scene.usage_flag_pointers["NORMALMAP"] = &p_shader->spatial.uses_tangent;
+
 			shaders.actions_scene.write_flag_pointers["MODELVIEW_MATRIX"] = &p_shader->spatial.writes_modelview_or_projection;
 			shaders.actions_scene.write_flag_pointers["PROJECTION_MATRIX"] = &p_shader->spatial.writes_modelview_or_projection;
 			shaders.actions_scene.write_flag_pointers["VERTEX"] = &p_shader->spatial.uses_vertex;
@@ -2726,6 +2735,36 @@ bool RasterizerStorageGLES3::material_casts_shadows(RID p_material) {
 	return casts_shadows;
 }
 
+bool RasterizerStorageGLES3::material_uses_tangents(RID p_material) {
+	Material *material = material_owner.get(p_material);
+	ERR_FAIL_COND_V(!material, false);
+
+	if (!material->shader) {
+		return false;
+	}
+
+	if (material->shader->dirty_list.in_list()) {
+		_update_shader(material->shader);
+	}
+
+	return material->shader->spatial.uses_tangent;
+}
+
+bool RasterizerStorageGLES3::material_uses_ensure_correct_normals(RID p_material) {
+	Material *material = material_owner.get(p_material);
+	ERR_FAIL_COND_V(!material, false);
+
+	if (!material->shader) {
+		return false;
+	}
+
+	if (material->shader->dirty_list.in_list()) {
+		_update_shader(material->shader);
+	}
+
+	return material->shader->spatial.uses_ensure_correct_normals;
+}
+
 void RasterizerStorageGLES3::material_add_instance_owner(RID p_material, RasterizerScene::InstanceBase *p_instance) {
 
 	Material *material = material_owner.get(p_material);

drivers/gles3/rasterizer_storage_gles3.h

@@ -499,6 +499,8 @@ class RasterizerStorageGLES3 : public RasterizerStorage {
 			bool uses_screen_texture;
 			bool uses_depth_texture;
 			bool uses_time;
+			bool uses_tangent;
+			bool uses_ensure_correct_normals;
 			bool writes_modelview_or_projection;
 			bool uses_vertex_lighting;
 			bool uses_world_coordinates;
@@ -606,6 +608,8 @@ class RasterizerStorageGLES3 : public RasterizerStorage {
 
 	virtual bool material_is_animated(RID p_material);
 	virtual bool material_casts_shadows(RID p_material);
+	virtual bool material_uses_tangents(RID p_material);
+	virtual bool material_uses_ensure_correct_normals(RID p_material);
 
 	virtual void material_add_instance_owner(RID p_material, RasterizerScene::InstanceBase *p_instance);
 	virtual void material_remove_instance_owner(RID p_material, RasterizerScene::InstanceBase *p_instance);