Shadows don't update when changing blend shape values

[RedMser]

Shadows don't update when changing blend shape values

[clayjohn]

This will need a bit of investigation to track down. But I think there is one of three things to look for:

1. We may need to notify the dependency system that the variable changed like we do for skeletons:
   

   godot/servers/rendering/renderer_rd/storage_rd/mesh_storage.cpp

   Line 2293 in c4279fe

   skeleton->dependency.changed_notify(Dependency::DEPENDENCY_CHANGED_SKELETON_BONES);

2. We may need to set the instance to dirty some other way when updating blend shapes. Maybe here:
   

   godot/servers/rendering/renderer_rd/storage_rd/mesh_storage.cpp

   Lines 917 to 924 in c4279fe

   	void MeshStorage::mesh_instance_set_blend_shape_weight(RID p_mesh_instance, int p_shape, float p_weight) {
   	MeshInstance *mi = mesh_instance_owner.get_or_null(p_mesh_instance);
   	ERR_FAIL_NULL(mi);
   	ERR_FAIL_INDEX(p_shape, (int)mi->blend_weights.size());
   	mi->blend_weights[p_shape] = p_weight;
   	mi->weights_dirty = true;
   	//will be eventually updated
   	}

For context instance_set_blend_shape_weight() will try to update the instance if it is already dirty.

godot/servers/rendering/renderer_scene_cull.cpp

Lines 950 to 961 in c4279fe

	void RendererSceneCull::instance_set_blend_shape_weight(RID p_instance, int p_shape, float p_weight) {
	Instance *instance = instance_owner.get_or_null(p_instance);
	ERR_FAIL_NULL(instance);
	if (instance->update_item.in_list()) {
	_update_dirty_instance(instance);
	}
	if (instance->mesh_instance.is_valid()) {
	RSG::mesh_storage->mesh_instance_set_blend_shape_weight(instance->mesh_instance, p_shape, p_weight);
	}
	}

If the instance is flagged as dirty, then we will mark the shadows as dirty. But we could also do it manually when blend shapes are modified:

godot/servers/rendering/renderer_scene_cull.cpp

Lines 884 to 889 in c4279fe

	if (geom->can_cast_shadows) {
	for (HashSet<RendererSceneCull::Instance *>::Iterator I = geom->lights.begin(); I != geom->lights.end(); ++I) {
	InstanceLightData *light = static_cast<InstanceLightData *>((*I)->base_data);
	light->make_shadow_dirty();
	}
	}