1 files changed, 24 insertions, 6 deletions

diff --git a/scene/3d/mesh_instance_3d.cpp b/scene/3d/mesh_instance_3d.cpp
index d4f60503c2..10f3ab5c79 100644
--- a/scene/3d/mesh_instance_3d.cpp
+++ b/scene/3d/mesh_instance_3d.cpp
@@ -33,6 +33,8 @@
 #include "collision_shape_3d.h"
 #include "core/core_string_names.h"
 #include "physics_body_3d.h"
+#include "scene/resources/concave_polygon_shape_3d.h"
+#include "scene/resources/convex_polygon_shape_3d.h"
 
 bool MeshInstance3D::_set(const StringName &p_name, const Variant &p_value) {
 	//this is not _too_ bad performance wise, really. it only arrives here if the property was not set anywhere else.
@@ -50,11 +52,22 @@ bool MeshInstance3D::_set(const StringName &p_name, const Variant &p_value) {
 
 	if (p_name.operator String().begins_with("surface_material_override/")) {
 		int idx = p_name.operator String().get_slicec('/', 1).to_int();
-		if (idx >= surface_override_materials.size() || idx < 0) {
+
+		// This is a bit of a hack to ensure compatibility with older material
+		// overrides that start indexing at 0.
+		// We assume that idx 0 is always read first, if its not, this won't work.
+		if (idx == 0) {
+			old_surface_index = true;
+		}
+		if (old_surface_index) {
+			idx++;
+		}
+
+		if (idx > surface_override_materials.size() || idx < 0) {
 			return false;
 		}
 
-		set_surface_override_material(idx, p_value);
+		set_surface_override_material(idx - 1, p_value);
 		return true;
 	}
 
@@ -73,7 +86,7 @@ bool MeshInstance3D::_get(const StringName &p_name, Variant &r_ret) const {
 	}
 
 	if (p_name.operator String().begins_with("surface_material_override/")) {
-		int idx = p_name.operator String().get_slicec('/', 1).to_int();
+		int idx = p_name.operator String().get_slicec('/', 1).to_int() - 1;
 		if (idx >= surface_override_materials.size() || idx < 0) {
 			return false;
 		}
@@ -96,7 +109,7 @@ void MeshInstance3D::_get_property_list(List<PropertyInfo> *p_list) const {
 	}
 
 	if (mesh.is_valid()) {
-		for (int i = 0; i < mesh->get_surface_count(); i++) {
+		for (int i = 1; i <= mesh->get_surface_count(); i++) {
 			p_list->push_back(PropertyInfo(Variant::OBJECT, vformat("%s/%d", PNAME("surface_material_override"), i), PROPERTY_HINT_RESOURCE_TYPE, "BaseMaterial3D,ShaderMaterial", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_DEFERRED_SET_RESOURCE));
 		}
 	}
@@ -224,7 +237,7 @@ Node *MeshInstance3D::create_trimesh_collision_node() {
 		return nullptr;
 	}
 
-	Ref<Shape3D> shape = mesh->create_trimesh_shape();
+	Ref<ConcavePolygonShape3D> shape = mesh->create_trimesh_shape();
 	if (shape.is_null()) {
 		return nullptr;
 	}
@@ -254,7 +267,7 @@ Node *MeshInstance3D::create_convex_collision_node(bool p_clean, bool p_simplify
 		return nullptr;
 	}
 
-	Ref<Shape3D> shape = mesh->create_convex_shape(p_clean, p_simplify);
+	Ref<ConvexPolygonShape3D> shape = mesh->create_convex_shape(p_clean, p_simplify);
 	if (shape.is_null()) {
 		return nullptr;
 	}
@@ -320,6 +333,11 @@ void MeshInstance3D::_notification(int p_what) {
 		case NOTIFICATION_ENTER_TREE: {
 			_resolve_skeleton_path();
 		} break;
+		case NOTIFICATION_TRANSLATION_CHANGED: {
+			if (mesh.is_valid()) {
+				mesh->notification(NOTIFICATION_TRANSLATION_CHANGED);
+			}
+		} break;
 	}
 }