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Export instance geometries to Sketchup
Open, Confirmed, LowPublic

Description

Hi,

according with this page Sketchup needs <instance_node> and <library_nodes> section for instancing geometries.

Blender Collada Exporter does different and when I import in Sketchup the geometries are not instances anymore.

Is there a way to improve the export between the two softwares?

Thank you.

Details

Type
Design

Event Timeline

This sounds like a reasonable request.

I know it is easy to setup, but still it would help me a lot if you can add a simple model (blend file) so i have something to look at and be sure we talk about the same thing.
Also can you indicate in detail what you expect to see in the dae file and how it differs from what Blender does at the moment?

This would let me get started a lot faster :)

thanks

Hi Gaia,

Please find attached the blend file, the collada file exported from Blender (cube.dae) and the file modified by me (cube_mod.dae) which works as I expect. In the modified file I added few comments to show what I changed.

Thank you so much,

Luca

Sergey Sharybin (sergey) triaged this task as Normal priority.Jun 9 2017, 11:08 AM
Gaia Clary (gaiaclary) changed Type from Bug to Design.Jan 31 2018, 6:26 PM
Gaia Clary (gaiaclary) lowered the priority of this task from Normal to Confirmed, Low.Jan 31 2018, 6:55 PM

According to Collada the Node library is used for organizing scenes with many objects into manageable subgroups (see citations at bottom of page). If i understand correct, then your request introduces one library Node per instance_geometry. This adds one level of hierarchy to the exported data:

visual_scene:node -> instance_node -> library:node -> instance_geometry

compared to what we have today:

visual_scene:node -> instance_geometry

The only solution i can see here is to add an export option for switching between "Export with instance_geometry" and "Export with instance_node". BTW the collada importer can handle both variants.

I have marked this report as "Design" and put it into my "feature request basket". Please let me know if you agree.

cheers,
Gaia

from the collada specification 1.4 (library_nodes):
As data sets become larger and more complex, they become harder to manipulate within a single
container. One approach to manage this complexity is to divide the data into smaller pieces organized by
some criteria. These modular pieces can then be stored in separate resources as libraries.

from the collada specification 1.4 (instance_node):
An <instance_node> creates an instance of an object described by a <node> element. Each instance
of a <node> element refers to an element in the <node> hierarchy that has its own local coordinate
system defined for placing objects in the scene.

from the collada specification 1.4 (instance_geometry):
The <instance_geometry> element instantiates an object described by a <geometry> element. A
geometry object is instantiated within the local coordinate system of its parent <node> or <shape> and
that determines its position, orientation, and scale.

Hi Gaia,

Nice to hear from you.

You are correct: the node library is useful when there are repeated subgrups of objects: for example a repeated window on a facade.
I suppose that the solution you proposed can solve the problem.

Cheers,

Luca