depsgraph object instance 'matrix_world' always returns identity matrix #60580

New Issue

Jonathan Dent · 2019-01-16T23:18:56+01:00

Jonathan Dent commented

2019-01-16 23:18:56 +01:00

Steps to reproduce:

Open a default scene
Open the Python console, type

for obj in C.depsgraph.object_instances:
    obj.matrix_world

You'll get back three identity matrices:

1 0 0 0
0 1 0 0
0 0 1 0
0 0 0 1

This behavior is duplicated in rendering as well.

Steps to reproduce: Open a default scene Open the Python console, type ``` for obj in C.depsgraph.object_instances: obj.matrix_world ``` You'll get back three identity matrices: 1 0 0 0 0 1 0 0 0 0 1 0 0 0 0 1 This behavior is duplicated in rendering as well.

Jonathan Dent commented

2019-01-16 23:18:56 +01:00

Added subscriber: @jdent02

Philipp Oeser commented

2019-01-17 11:08:34 +01:00

Added subscribers: @mont29, @lichtwerk

Philipp Oeser commented

2019-01-17 11:08:34 +01:00

Isnt this meant for duplis / instances?
(checking is_instance on ob will tell you if this is the case)

Looking at the code seems to suggest this:

static void rna_DepsgraphObjectInstance_matrix_world_get(PointerRNA *ptr, float *mat)
{
	BLI_Iterator *iterator = ptr->data;
	DEGObjectIterData *deg_iter = (DEGObjectIterData *)iterator->data;
	if (deg_iter->dupli_object_current != NULL) {
		copy_m4_m4((float(*)[4])mat, deg_iter->dupli_object_current->mat);
	}
	else {
		unit_m4((float(*)[4])mat);
	}
}

Not sure if I understand DepsgraphObjectInstance correct though, maybe @mont29 could share his wisdom?

Isnt this meant for duplis / instances? (checking `is_instance` on `ob` will tell you if this is the case) Looking at the code seems to suggest this: ``` static void rna_DepsgraphObjectInstance_matrix_world_get(PointerRNA *ptr, float *mat) { BLI_Iterator *iterator = ptr->data; DEGObjectIterData *deg_iter = (DEGObjectIterData *)iterator->data; if (deg_iter->dupli_object_current != NULL) { copy_m4_m4((float(*)[4])mat, deg_iter->dupli_object_current->mat); } else { unit_m4((float(*)[4])mat); } } ``` Not sure if I understand `DepsgraphObjectInstance` correct though, maybe @mont29 could share his wisdom?

blender-admin commented

2019-01-17 12:28:50 +01:00

This issue was referenced by d86991ef37

This issue was referenced by d86991ef378cb9220dfb8e9e6cbbd734e81de052

Bastien Montagne self-assigned this 2019-01-17 12:32:38 +01:00

Bastien Montagne commented

2019-01-17 12:32:38 +01:00

This is indeed not a bug, for non-instance items, people should typically only access the 'object' member.

But there is no good reasons (beside very strict consistency) to not fill matrix_world from that object in RNA... This is exact same data for both dupliinstances and objects here (and think it's the only one).

This is indeed not a bug, for non-instance items, people should typically only access the 'object' member. But there is no good reasons (beside very strict consistency) to not fill matrix_world from that object in RNA... This is exact same data for both dupliinstances and objects here (and think it's the only one).

Bastien Montagne commented

2019-01-17 12:36:59 +01:00

Changed status from 'Open' to: 'Resolved'

Bastien Montagne closed this issue

2019-01-17 12:36:59 +01:00

Jonathan Dent commented

2019-01-17 13:07:07 +01:00

If that’s the case I would suggest you guys update the Python API docs for DepsgraphObjectInstance. As you can see below there’s no indication at all that it only applies to duplis.

matrix_world
Generated transform matrix in world space

Type: float multi-dimensional array of 4 * 4 items in [-inf, inf], default ((0.0, 0.0, 0.0, 0.0), (0.0, 0.0, 0.0, 0.0), (0.0, 0.0, 0.0, 0.0), (0.0, 0.0, 0.0, 0.0)), (readonly)

If that’s the case I would suggest you guys update the Python API docs for DepsgraphObjectInstance. As you can see below there’s no indication at all that it only applies to duplis. matrix_world Generated transform matrix in world space Type: float multi-dimensional array of 4 * 4 items in [-inf, inf], default ((0.0, 0.0, 0.0, 0.0), (0.0, 0.0, 0.0, 0.0), (0.0, 0.0, 0.0, 0.0), (0.0, 0.0, 0.0, 0.0)), (readonly)

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depsgraph object instance 'matrix_world' always returns identity matrix #60580