Blender Foundation: Blender 2.x BF release: Detail: 26212 ParticleSystem.particles issues

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[#26212] ParticleSystem.particles issues

Date:
2011-02-24 23:48 Priority:
3

State:
Closed

Submitted by:
Doug Hammond (dougal2) Assigned to:
Janne Karhu (jhk)

Category:
None Status:
Fixed / Closed

Relates to: Duplicates:

Patches:

Summary:
ParticleSystem.particles issues

Detailed description

I've come up against several issues when trying to export Hair particle systems.

I'm accessing particles via object.particle_systems[i].particles

The main issues so far are:

1)
I've tried various baking options and I cannot get the list of particles to return anything other than the data present in the first frame in the scene. This is a problem when the hair system uses Hair Dynamics.

2)
The list of particles returned corresponds to the Display %, and not the full 100% needed for rendering.

Followup

Message

Date: 2011-02-25 14:42
Sender: Doug Hammond
Hi Janne,

I know we talked about similar behaviour with other particles before. Could it be possible that the API could get a new method similar to create_dupli_list (create_particle_list ?) which constructs a temporary list of particles to use for export?

Date: 2011-03-23 11:59
Sender: Janne Karhu
I've now committed a fix for the firs problem in r35721. There's now a new value in the hair keys called "co_dynamic", which contains the data from the hair dynamics.

The second issue is the same one (although even a bit more complicated for hair) than the previous one we discussed. The only workaround I see is to call a separate script to set the particle display percentages before actual rendering is started and call it again after rendering to restore the percentages.

The underlying problem is that rendering thread and ui drawing thread use the same scene data, so updating something while rendering can crash very easily (this is why changing stuff from python is blocked during rendering currently). This is a much bigger problem than just the problem it causes for exporting and hopefully it will be solved in the near future. If/hopefully when the write restrictions during render are lifted you can use the same workaround of manually setting the view percentages, tagging the objects for update and doing a scene.update() call.

I'll close this report for now, since this will hopefully become a non-issue once the underlying thread conflict is fixed.

Attached Files:

No Files Currently Attached

Changes:

Field	Old Value	Date	By

status_id	Open	2011-03-23 11:59	jhk
close_date	None	2011-03-23 11:59	jhk
Status	New	2011-03-23 11:59	jhk
assigned_to	none	2011-02-25 02:38	campbellbarton