EEVEE-Next: UI: Make Vector pass greyed out when motion blur is enabled

Also clears the render result to 0 to avoid invalid motion vectors.

2 files changed, 13 insertions, 1 deletions

diff --git a/release/scripts/startup/bl_ui/properties_view_layer.py b/release/scripts/startup/bl_ui/properties_view_layer.py
index 01bd0adc8df..78aec096510 100644
--- a/release/scripts/startup/bl_ui/properties_view_layer.py
+++ b/release/scripts/startup/bl_ui/properties_view_layer.py
@@ -79,6 +79,7 @@ class VIEWLAYER_PT_eevee_next_layer_passes_data(ViewLayerButtonsPanel, Panel):
         layout.use_property_split = True
         layout.use_property_decorate = False
 
+        scene = context.scene
         view_layer = context.view_layer
 
         col = layout.column()
@@ -87,7 +88,9 @@ class VIEWLAYER_PT_eevee_next_layer_passes_data(ViewLayerButtonsPanel, Panel):
         col.prop(view_layer, "use_pass_mist")
         col.prop(view_layer, "use_pass_normal")
         col.prop(view_layer, "use_pass_position")
-        col.prop(view_layer, "use_pass_vector")
+        sub = col.column()
+        sub.active = not scene.eevee.use_motion_blur
+        sub.prop(view_layer, "use_pass_vector")
 
 
 class VIEWLAYER_PT_eevee_layer_passes_light(ViewLayerButtonsPanel, Panel):
diff --git a/source/blender/draw/engines/eevee_next/eevee_instance.cc b/source/blender/draw/engines/eevee_next/eevee_instance.cc
index fe347eed7b1..70b5cb7d98f 100644
--- a/source/blender/draw/engines/eevee_next/eevee_instance.cc
+++ b/source/blender/draw/engines/eevee_next/eevee_instance.cc
@@ -242,6 +242,15 @@ void Instance::render_read_result(RenderLayer *render_layer, const char *view_na
       }
     }
   }
+
+  /* The vector pass is initialized to weird values. Set it to neutral value if not rendered. */
+  if ((pass_bits & EEVEE_RENDER_PASS_VECTOR) == 0) {
+    const char *vector_pass_name = Film::pass_to_render_pass_name(EEVEE_RENDER_PASS_VECTOR);
+    RenderPass *vector_rp = RE_pass_find_by_name(render_layer, vector_pass_name, view_name);
+    if (vector_rp) {
+      memset(vector_rp->rect, 0, sizeof(float) * 4 * vector_rp->rectx * vector_rp->recty);
+    }
+  }
 }
 
 /** \} */