Alembic Import Motion Blur Blender Particles / Points #108038

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2023-05-18 17:14:00 +02:00

labels 2023-05-18 15:03:28 +02:00

Sterling Osment commented

Add a plane, rotate it 90 on x, add a particle system, set the gravity to zero, add a wind and turbulence, set the strength to 5 on each, check it in 50000 particles, then set it to 1million, and bake. Export the particle system via alembic with only selected.

New scene, import abc, add a cube and enable geometry node for that object, drag the particle abc import into the GN node space. As object info/relative.

Joins geo, set position, mesh to points, set point radius.
Add noise texture, vector math subtract, vector math scale and join to offset. After set point radius add set material and apply principled bsdf.

Render panel, check motion blur, set it to 1.

Add a plane, rotate it 90 on x, add a particle system, set the gravity to zero, add a wind and turbulence, set the strength to 5 on each, check it in 50000 particles, then set it to 1million, and bake. Export the particle system via alembic with only selected. New scene, import abc, add a cube and enable geometry node for that object, drag the particle abc import into the GN node space. As object info/relative. Joins geo, set position, mesh to points, set point radius. Add noise texture, vector math subtract, vector math scale and join to offset. After set point radius add set material and apply principled bsdf. Render panel, check motion blur, set it to 1.

Iliya Katushenock added

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2023-05-19 01:50:22 +02:00

labels 2023-05-18 17:19:13 +02:00

Sterling Osment commented

I have been reading other threads on this issue and its seem Blender particles on abc export dont attach a vector or velocity attribute. tested in 3.3.3 and 3.3.6

Iliya Katushenock commented

2023-05-19 23:18:26 +02:00

Can you reproduce this in 3.6?

Richard Antalik commented

2023-05-24 06:40:51 +02:00

I have been reading other threads on this issue and its seem Blender particles on abc export dont attach a vector or velocity attribute. tested in 3.3.3 and 3.3.6

I think there was quite similar repot to this, but can't find it. Now I am not sure whether this should be supported or not.

> I have been reading other threads on this issue and its seem Blender particles on abc export dont attach a vector or velocity attribute. tested in 3.3.3 and 3.3.6 I think there was quite similar repot to this, but can't find it. Now I am not sure whether this should be supported or not.

Sterling Osment commented

2023-05-24 11:59:09 +02:00

@iss well I guess, its a tricky one as Simulation nodes are on the cusp - the hard part is how long the grey area will be for users. This technique was working fine in older versions, not sure why it was dropped.

The ability to run particle systems quickly and bootstrap them to geometry nodes is super powerful.

If your not week to week on the pulse for Geometry Nodes - it can be very difficult to find good learning reference for a particular shot or method.

It becomes an RandD session sifting thorough 100's of videos picking things out and correlating workflows to use. There's no Geometry Nodes cookbook. Plus Blender seems to forget to add Presets or setups by default.

Building things from scratch is very tiring and makes it difficult to pitch timeframes. I refer to Houdini's shelf setups, they offer some launchpad for Fluids and Smoke sims etc.

So if you do decide to add alembic cycle workflow it would be fully appreciated - and motion vectors on export would also be amazing.

@iss well I guess, its a tricky one as Simulation nodes are on the cusp - the hard part is how long the grey area will be for users. This technique was working fine in older versions, not sure why it was dropped. The ability to run particle systems quickly and bootstrap them to geometry nodes is super powerful. If your not week to week on the pulse for Geometry Nodes - it can be very difficult to find good learning reference for a particular shot or method. It becomes an RandD session sifting thorough 100's of videos picking things out and correlating workflows to use. There's no Geometry Nodes cookbook. Plus Blender seems to forget to add Presets or setups by default. Building things from scratch is very tiring and makes it difficult to pitch timeframes. I refer to Houdini's shelf setups, they offer some launchpad for Fluids and Smoke sims etc. So if you do decide to add alembic cycle workflow it would be fully appreciated - and motion vectors on export would also be amazing.

Sterling Osment commented

2023-05-24 12:01:11 +02:00

Can you reproduce this in 3.6?

@mod_moder Yes same result. no motion blur.

> Can you reproduce this in 3.6? @mod_moder Yes same result. no motion blur.

Richard Antalik commented

2023-05-25 03:31:19 +02:00

@Sterling-Osment So if I understand this correctly - when you export particles made with old system as ABC, there is no issue, but with geo nodes there is? Or is the issue, that geo nodes on imported particles will cause motion blur to not work?

Richard Antalik added

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2023-05-25 14:58:11 +02:00

labels 2023-05-25 03:33:35 +02:00

Sterling Osment commented

@mod_moder sorry mis read your comment, haven’t tried 3.6

Sterling Osment commented

2023-05-25 15:08:36 +02:00

@iss well the old particle system doesn’t strap the vector abc data to the points and geometry nodes doesn’t have the data to read on the way out for motion blur. I guess I will have to try 3.6 but as I’m using 3.3.6 LTS for production, I have a preference to use this version hoping the performance would be clean.

Side note caching in 3.3.6 is very buggy. Literally have to physically save as to engage a cache every time. Not ctrl-s. Otherwise the cache just slips and doesn’t write to disk.

I understand that GN is moving to sim nodes but LTS should have a tidy workflow for legacy processes.

@iss well the old particle system doesn’t strap the vector abc data to the points and geometry nodes doesn’t have the data to read on the way out for motion blur. I guess I will have to try 3.6 but as I’m using 3.3.6 LTS for production, I have a preference to use this version hoping the performance would be clean. Side note caching in 3.3.6 is very buggy. Literally have to physically save as to engage a cache every time. Not ctrl-s. Otherwise the cache just slips and doesn’t write to disk. I understand that GN is moving to sim nodes but LTS should have a tidy workflow for legacy processes.

Richard Antalik commented

2023-05-26 06:42:58 +02:00

@Sterling-Osment I am still quite unsure about workflow there, can you provide steps for minimal reproducible case?

As for LTS, it's purpose is to provide critical bugfixes for crashes and such. It has nothing to do with how features are polished. For reporting bugs, please always check latest alpha/beta builds since that is where bugfixes are applied to.

@Sterling-Osment I am still quite unsure about workflow there, can you provide steps for minimal reproducible case? As for LTS, it's purpose is to provide critical bugfixes for crashes and such. It has nothing to do with how features are polished. For reporting bugs, please always check latest alpha/beta builds since that is where bugfixes are applied to.

Gad commented

2023-05-30 16:54:21 +02:00

Hi,
I have same issue - exporting from Houdini points as alembic.
Importing Alembic in Blender.
Adding geonodes -> mesh to points (to let me render points in Cycles)
???
Pointcloud have no motionblur.
In Spreadsheet there's no information about any bundled to alembic data. (for example Id, Age, Color).

Hi, I have same issue - exporting from Houdini points as alembic. Importing Alembic in Blender. Adding geonodes -> mesh to points (to let me render points in Cycles) ??? Pointcloud have no motionblur. In Spreadsheet there's no information about any bundled to alembic data. (for example Id, Age, Color). ![image](/attachments/c5d406fe-da9e-473e-9719-34c650b59a95)

image.png

154 KiB

Richard Antalik added

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2023-06-22 08:22:18 +02:00

labels 2023-06-12 04:40:18 +02:00

Pratik Borhade commented

Hi, can you share .blend file with us?

As far as I know, exporting attributes is not supported yet in alembic format, see: #108937 (comment)

Hi, can you share .blend file with us? As far as I know, exporting attributes is not supported yet in alembic format, see: https://projects.blender.org/blender/blender/issues/108937#issuecomment-960356

Pratik Borhade added

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2023-07-18 07:52:07 +02:00

labels 2023-06-22 08:22:27 +02:00

Pratik Borhade commented

Any updates?

Richard Antalik commented

2023-09-02 03:56:21 +02:00

No activity for more than a week. As per the tracker policy we assume the issue is gone and can be closed.

Thanks again for the report. If the problem persists please open a new report with the required information.

No activity for more than a week. As per the tracker policy we assume the issue is gone and can be closed. Thanks again for the report. If the problem persists please open a new report with the required information.

Richard Antalik closed this issue

2023-09-02 03:56:25 +02:00

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