Particle Info Node Does Not Consider Time Remapping
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Description

System Information
Operating system:version: 2.90 (sub 0), branch: master, commit date: 2020-05-08 16:22, hash: 6f985574b775, type: Release
build date: 2020-05-08, 21:30:40
Graphics card: gtx660

Blender Version
Broken: (example: 2.80, edbf15d3c044, master, 2018-11-28, as found on the splash screen)
Worked: (newest version of Blender that worked as expected)

Short description of error
Particle Age Attribute Is Wrong When Time Is Remapped

Exact steps for others to reproduce the error
Open the attached file and activate Rendered viewport shading (Cycles).
Scrub the timeline and you'll see the the particles inherit colors based upon their age.
Press F12 and you will discover that all particles are rendered green. This is because the OLD field in the time remapping section is not equal to the NEW field.
If you set the NEW value equal to the OLD value, the colors render correctly.

The attributes presented by the particle info node should take into account the time remapping values.

Better yet, why don't we have a Timeline info node that provides basic information about the start, end frame, fps and time remapping? If this node existed more complicated node graphs could be crafted.

Particles2 - Copy.blend48 MBDownload

Revisions and Commits

rB Blender
	D12239	rB23132fcdc136 Fix T77307: Particle Info Node Does Not Consider Time Remapping

Event Timeline

Atomic (atomic) created this task.Jun 3 2020, 3:14 PM

Philipp Oeser (lichtwerk) changed the task status from Needs Triage to Confirmed.Jun 3 2020, 3:45 PM

Philipp Oeser (lichtwerk) updated the task description. (Show Details)

Philipp Oeser (lichtwerk) added projects: Render & Cycles, Nodes.

I tried looking into this a bit and noticed a couple of things:

rendering is wrong, yes
I think the remapping values are actually taken into account [if you have old<>new 100<>50, and compare scrubbing to 400 instead of 200 the results are actually the same]
however, there is something weird going on with updating here
when in the timeline scrubbing, pressing the mouse (not releasing!) somewhere in the timeline will most certainly yield to "wrong" (green -- same as rendering) results, yet when you release chances are good that result return back to the correct result.

This might help tracking down where the updates in the timeline as well as rendering might go wrong, needs further investigation...
note: change_frame_applyis done in both modal as well as confirming when scrubbing in the timeline

If this was just about particles, I would not hold my breath here [since particle nodes are around the corner], but this might also be an issue with setting CFRA (current frame) elsewhere?

when in the timeline scrubbing, pressing the mouse (not releasing!) somewhere in the timeline will most certainly yield to "wrong" (green -- same as rendering) results, yet when you release chances are good that result return back to the correct result.

Can confirm on Blender 2.83.

Philipp Oeser (lichtwerk) added a project: Nodes & Physics.Jun 8 2020, 10:05 AM