Maniphest T56483

Particle instance modifier actually copies, not instantiates objects
Closed, Archived
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Assigned To
Brecht Van Lommel (brecht)
Authored By
Yegor (Yegor)
Aug 21 2018, 5:39 PM
Tags
  • BF Blender
Subscribers
Brecht Van Lommel (brecht)
Yegor (Yegor)
Yevgeny Makarov (jenkm)

Description

System Information
Debian testing, Nvidia GTX 1080ti

Blender Version
Broken: 2.79b, latest from master

Short description of error
Seems to be that particle instance modifier actually copies, not instantiates objects.
There is a significant memory usage and performance drop while using the particle instance modifier and subsurf.
If we use the hair particle system with the same dupli object in it, we don't get this behavior.

Dupli-object in the hair particle system with subsurf: ~7Mb
Particle instance modifier : ~312Mb

Exact steps for others to reproduce the error

  • Open the attached file
  • Hit render - get 312Mb wasted
  • Uncheck particle instance modifies render and viewport visibility on the Pin object
  • Check Plane -> Particle system -> Render -> Object -> Pin to make dupliobjects on the plane
  • Render - get 7Mb wasted

blender_particle_instance.blend1 MBDownload

Related Objects

Event Timeline

Yegor (Yegor) created this task.Aug 21 2018, 5:39 PM
Yevgeny Makarov (jenkm) added a subscriber: Yevgeny Makarov (jenkm).Aug 21 2018, 5:57 PM

The Particle Instance modifier edits the mesh of an object,
rather than creating copies/instances of that object.

T54277

Yegor (Yegor) added a comment.Aug 21 2018, 6:16 PM

So we cannot dynamically deform instances as hairs in memory efficient way... That is sad.

Brecht Van Lommel (brecht) changed the task status from Unknown Status to Unknown Status.Aug 21 2018, 10:53 PM
Brecht Van Lommel (brecht) claimed this task.
Brecht Van Lommel (brecht) added a subscriber: Brecht Van Lommel (brecht).

That's correct, modifiers don't do instancing, that's not considered a bug but more a design limitation.