Merge pull request #108664 from clayjohn/TAA-motion-vectors-alpha

Never overwrite motion vectors in the transparent pass

servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp

@@ -2359,10 +2359,8 @@ void RenderForwardClustered::_render_scene(RenderDataRD *p_render_data, const Co
 
 	{
 		uint32_t transparent_color_pass_flags = (color_pass_flags | uint32_t(COLOR_PASS_FLAG_TRANSPARENT)) & ~uint32_t(COLOR_PASS_FLAG_SEPARATE_SPECULAR);
-		if (using_motion_pass) {
-			// Motion vectors on transparent draw calls are not required when using the reactive mask.
-			transparent_color_pass_flags &= ~uint32_t(COLOR_PASS_FLAG_MOTION_VECTORS);
-		}
+		// Motion vectors should not be overwritten by transparent objects.
+		transparent_color_pass_flags &= ~uint32_t(COLOR_PASS_FLAG_MOTION_VECTORS);
 
 		RID alpha_framebuffer = rb_data.is_valid() ? rb_data->get_color_pass_fb(transparent_color_pass_flags) : color_only_framebuffer;
 		RenderListParameters render_list_params(render_list[RENDER_LIST_ALPHA].elements.ptr(), render_list[RENDER_LIST_ALPHA].element_info.ptr(), render_list[RENDER_LIST_ALPHA].elements.size(), reverse_cull, PASS_MODE_COLOR, transparent_color_pass_flags, rb_data.is_null(), p_render_data->directional_light_soft_shadows, rp_uniform_set, get_debug_draw_mode() == RS::VIEWPORT_DEBUG_DRAW_WIREFRAME, Vector2(), p_render_data->scene_data->lod_distance_multiplier, p_render_data->scene_data->screen_mesh_lod_threshold, p_render_data->scene_data->view_count, 0, base_specialization);