Switching Grease Pencil material slot link to Object and back to Data corrupts material #64896

New Issue

matc · 2019-05-20T20:15:55+02:00

matc commented

2019-05-20 20:15:55 +02:00

Blender Version
Broken: 9efe117535, master, 2018-05-20

Short description of error
For normal objects switching a material slot link to Object and back to Data will result in the material to reappear in the slot. For Grease Pencil objects the material in the slot will point to 0xcccc.... This causes blender to crash while rendering the viewport.

Exact steps for others to reproduce the error

File -> New -> 2D Animation
Switch Link of material slot to Object (Bottom right button in material slot selector.)
Switch Link of same material slot back to Data
Blender crashes on viewport render

**Blender Version** Broken: 9efe117535c6, master, 2018-05-20 **Short description of error** For normal objects switching a material slot link to Object and back to Data will result in the material to reappear in the slot. For Grease Pencil objects the material in the slot will point to `0xcccc...`. This causes blender to crash while rendering the viewport. **Exact steps for others to reproduce the error** - File -> New -> 2D Animation - Switch **Link** of material slot to **Object** (Bottom right button in material slot selector.) - Switch **Link** of same material slot back to **Data** - Blender crashes on viewport render

matc commented

2019-05-20 20:15:55 +02:00

Added subscriber: @matc

Antonio Vazquez was assigned by Brecht Van Lommel

2019-05-29 02:45:36 +02:00

Antonio Vazquez commented

2019-05-29 10:36:30 +02:00

Added subscriber: @brecht

Antonio Vazquez commented

2019-05-29 10:36:30 +02:00

@brecht I have been doing debug and I have seen the problem is when retry the material.

The material is recovered using

give_current_material(ob, ob->actcol);

You can find the code in BKE_gpencil_object_material_get_from_brush()

IIRC you told me the function give_current_material() Is used to get the mat for Data and for Objet mode, but in this case, the function is returning NaN. I have checked and the Object parameter is correct and the ob->actcol=1, so not sure why this is not working... at least the function could return NULL intead of garbage data.

Any idea?

@brecht I have been doing debug and I have seen the problem is when retry the material. The material is recovered using ``` give_current_material(ob, ob->actcol); ``` You can find the code in BKE_gpencil_object_material_get_from_brush() IIRC you told me the function give_current_material() Is used to get the mat for Data and for Objet mode, but in this case, the function is returning NaN. I have checked and the Object parameter is correct and the ob->actcol=1, so not sure why this is not working... at least the function could return NULL intead of garbage data. Any idea?

Antonio Vazquez commented

2019-05-29 10:44:16 +02:00

I have seen this in the console, not sure if related or not:

find_node_operation: Failed for (MATERIAL_UPDATE, '')
add_relation(Material -> GP Data) - Could not find op_from (OperationKey(type: SHADING, component name: '', operation code: MATERIAL_UPDATE))
add_relation(Material -> GP Data) - Failed, but op_to (ComponentKey(GDStroke, GEOMETRY)) was ok

I have seen this in the console, not sure if related or not: ``` find_node_operation: Failed for (MATERIAL_UPDATE, '') add_relation(Material -> GP Data) - Could not find op_from (OperationKey(type: SHADING, component name: '', operation code: MATERIAL_UPDATE)) add_relation(Material -> GP Data) - Failed, but op_to (ComponentKey(GDStroke, GEOMETRY)) was ok ```

matc commented

2019-06-01 00:43:04 +02:00

Could be that the problem is in DepsgraphNodeBuilder::build_object_data_geometry where only materials are handled which are returned by give_current_material. When setting a link to Object, then the material in ob->data is ignored. But I'm not sure how this wouldn't have caused problems with the default cube.

This would fix the problem:

diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
index 93e5dd14ae0..acdf08b7f32 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc
@@ -1191,9 +1191,19 @@ void DepsgraphNodeBuilder::build_object_data_geometry(Object *object, bool is_ob
       function_bind(BKE_object_eval_uber_data, _1, scene_cow, object_cow));
   op_node->set_as_exit();
   /* Materials. */
-  if (object->totcol != 0) {
-    for (int a = 1; a <= object->totcol; a++) {
-      Material *ma = give_current_material(object, a);
+  if (object->totcol) {
+    for (int a = 0; a < object->totcol; a++) {
+      Material *ma = object->mat[a];
+      if (ma != NULL) {
+        build_material(ma);
+      }
+    }
+  }
+  short *totcolp = give_totcolp(object);
+  if (*totcolp) {
+    Material ***matarar = give_matarar(object);
+    for (int a = 0; a < *totcolp; a++) {
+      Material *ma = (*matarar)[a];
       if (ma != NULL) {
         build_material(ma);
       }
diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
index 54d5223497e..117b1fd6d19 100644
--- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
+++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc
@@ -1918,8 +1918,18 @@ void DepsgraphRelationBuilder::build_object_data_geometry(Object *object)
   }
   /* Materials. */
   if (object->totcol) {
-    for (int a = 1; a <= object->totcol; a++) {
-      Material *ma = give_current_material(object, a);
+    for (int a = 0; a < object->totcol; a++) {
+      Material *ma = object->mat[a];
+      if (ma != NULL) {
+        build_material(ma);
+      }
+    }
+  }
+  short *totcolp = give_totcolp(object);
+  if (*totcolp) {
+    Material ***matarar = give_matarar(object);
+    for (int a = 0; a < *totcolp; a++) {
+      Material *ma = (*matarar)[a];
       if (ma != NULL) {
         build_material(ma);
       }

Could be that the problem is in `DepsgraphNodeBuilder::build_object_data_geometry` where only materials are handled which are returned by `give_current_material`. When setting a link to Object, then the material in `ob->data` is ignored. But I'm not sure how this wouldn't have caused problems with the default cube. This would fix the problem: ``` diff --git a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc index 93e5dd14ae0..acdf08b7f32 100644 --- a/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc +++ b/source/blender/depsgraph/intern/builder/deg_builder_nodes.cc @@ -1191,9 +1191,19 @@ void DepsgraphNodeBuilder::build_object_data_geometry(Object *object, bool is_ob function_bind(BKE_object_eval_uber_data, _1, scene_cow, object_cow)); op_node->set_as_exit(); /* Materials. */ - if (object->totcol != 0) { - for (int a = 1; a <= object->totcol; a++) { - Material *ma = give_current_material(object, a); + if (object->totcol) { + for (int a = 0; a < object->totcol; a++) { + Material *ma = object->mat[a]; + if (ma != NULL) { + build_material(ma); + } + } + } + short *totcolp = give_totcolp(object); + if (*totcolp) { + Material ***matarar = give_matarar(object); + for (int a = 0; a < *totcolp; a++) { + Material *ma = (*matarar)[a]; if (ma != NULL) { build_material(ma); } diff --git a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc index 54d5223497e..117b1fd6d19 100644 --- a/source/blender/depsgraph/intern/builder/deg_builder_relations.cc +++ b/source/blender/depsgraph/intern/builder/deg_builder_relations.cc @@ -1918,8 +1918,18 @@ void DepsgraphRelationBuilder::build_object_data_geometry(Object *object) } /* Materials. */ if (object->totcol) { - for (int a = 1; a <= object->totcol; a++) { - Material *ma = give_current_material(object, a); + for (int a = 0; a < object->totcol; a++) { + Material *ma = object->mat[a]; + if (ma != NULL) { + build_material(ma); + } + } + } + short *totcolp = give_totcolp(object); + if (*totcolp) { + Material ***matarar = give_matarar(object); + for (int a = 0; a < *totcolp; a++) { + Material *ma = (*matarar)[a]; if (ma != NULL) { build_material(ma); } ```

Antonio Vazquez commented

2019-09-13 13:26:26 +02:00

Added subscriber: @lichtwerk

Antonio Vazquez commented

2019-09-13 13:26:26 +02:00

@lichtwerk I don't know what to do here... maybe you need reassign to someone that knows how to fix it, because it looks something outside Gpencil code.

Antonio Vazquez was unassigned by Philipp Oeser

2019-09-13 13:49:10 +02:00

Philipp Oeser commented

2019-09-13 13:49:10 +02:00

Added subscriber: @antoniov

Antonio Vazquez commented

2020-01-23 19:23:59 +01:00

Closed as duplicate of #63757

Antonio Vazquez closed this issue

2020-01-23 19:23:59 +01:00

Antonio Vazquez commented

2020-01-23 19:25:54 +01:00

Closed by error. This has been fixed in #66293

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Switching Grease Pencil material slot link to Object and back to Data corrupts material #64896