[Bf-blender-cvs] [ca69a303e15] ui-asset-view-template: Fix T86172: check if attribute is actually accessible

[Jacques Lucke]

Commit: ca69a303e1588211e406534e4381cd4ea122c49e
Author: Jacques Lucke
Date:   Tue Mar 2 13:29:01 2021 +0100
Branches: ui-asset-view-template
https://developer.blender.org/rBca69a303e1588211e406534e4381cd4ea122c49e

Fix T86172: check if attribute is actually accessible

The crash happened when the density in the Point Distribute node was
above zero but so small, that no point was generated. In this case, there
was a point cloud component, but the point cloud was empty, making some
attributes unavailable.

One could also make more attributes available in this case, but that can
be done separately if necessary.

===================================================================

M	source/blender/blenkernel/intern/attribute_access.cc
M	source/blender/nodes/geometry/nodes/node_geo_point_scale.cc

===================================================================

diff --git a/source/blender/blenkernel/intern/attribute_access.cc b/source/blender/blenkernel/intern/attribute_access.cc
index 8974190d0e3..aeb7fba47e8 100644
--- a/source/blender/blenkernel/intern/attribute_access.cc
+++ b/source/blender/blenkernel/intern/attribute_access.cc
@@ -1886,7 +1886,7 @@ OutputAttributePtr GeometryComponent::attribute_try_get_for_output(const StringR
   if (!attribute) {
     this->attribute_try_create(attribute_name, domain, data_type);
     attribute = this->attribute_try_get_for_write(attribute_name);
-    if (default_value != nullptr) {
+    if (attribute && default_value != nullptr) {
       void *data = attribute->get_span_for_write_only().data();
       cpp_type->fill_initialized(default_value, data, attribute->size());
       attribute->apply_span();
diff --git a/source/blender/nodes/geometry/nodes/node_geo_point_scale.cc b/source/blender/nodes/geometry/nodes/node_geo_point_scale.cc
index e28013a8bfc..9df103ff057 100644
--- a/source/blender/nodes/geometry/nodes/node_geo_point_scale.cc
+++ b/source/blender/nodes/geometry/nodes/node_geo_point_scale.cc
@@ -47,6 +47,9 @@ static void execute_on_component(GeoNodeExecParams params, GeometryComponent &co
   static const float3 scale_default = float3(1.0f);
   OutputAttributePtr scale_attribute = component.attribute_try_get_for_output(
       "scale", ATTR_DOMAIN_POINT, CD_PROP_FLOAT3, &scale_default);
+  if (!scale_attribute) {
+    return;
+  }
   ReadAttributePtr attribute = params.get_input_attribute(
       "Factor", component, ATTR_DOMAIN_POINT, CD_PROP_FLOAT3, nullptr);
   if (!attribute) {