How to export the point cloud from a volume light

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So I need to delayed load some pyro volumes. I also need to use a volume light to illuminate the fire.

Does anyone know a workflow to use the volume light with delayed load?
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Does packed disk primitive work for you? I feel like I have used this to success before with volume lights, but I don't recall if pointclouds were enabled.
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I'll give packed prims a try on the farm with the volume light. I also need to export a point cloud. I can make it manually, but I was hoping the export file on the volume light would help me out. Seems like it only spits out a file if you render manually? If I put it on the farm, it doesn't write a file. But I could be doing something wrong.

Thanks for the tip!
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Packed Prims seems to have worked! Thanks for the tip!
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I am in need of a similar solution, I am using disk based instancing for 100s of pyro explosions. If I render the volumes as point instance procedurals. PTC does not get created. If I load the instances with instance sop as packed primitives in to the scene, it works and light shader creates the PTC.

So my question is whats the workflow of prebaking this PTC without sending a sudo render to farm.

Why, because I am releasing these caches to be instanced on points outside Houdini to be rendered from PRMAN, so I also will brebake the PTC to illuminate the instanced volumes in PRMAN.

How can I bake the PTC from inside Houdini;

A quick check reveals attributes like A,DIM,WEIGHT,AMOUNT and CD. Whats the workflow to create the exact same PTC…

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Figured out a way to render out the point cloud by keeping auto-generate point cloud on in a volume light and then launching a mantra render but changing the name of the path to the place for for the point cloud to be saved.

To just generate the point cloud quickly rather than wait to render I created a really fast mantra node that's 1x1 pixels that casts no rays, which only generates the point cloud.

Kind of a hack, but hey it works.

Would be nice to know what all the attributes on the point cloud file mean and how they were generated, which might give insight into how to build it in sops. Though, the mantra way does use the volume's shader for the lookup so it's more accurate, trade offs I suppose.

Anyways, here's a file, just hit render on the mantra node and it'll generate.

Annoyingly it doesn't create intermediate directories, bear that in mind if you change the file path in the geo light from $HIP/$OS.$F.pc

Tighe

Attachments:
pyroGenPointCloud_v1.hip (2.2 MB)

Tighe Rzankowski

trzankofx@gmail.com
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+1 to wanting to know exactly how to reproduce those attributes.

Pixar's point cloud baking is a lot more straightforward… I always wondered if Side Effects' point cloud tools were more opaque due to patent constraints by Pixar.
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To just generate the point cloud quickly rather than wait to render I created a really fast mantra node that's 1x1 pixels that casts no rays, which only generates the point cloud.
just uncheck Images/Output/Create Image From Viewing Camera, it's there exactly for this purpose
Edited by tamte - 2018年3月15日 00:17:52
Tomas Slancik
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tamte
trzanko
To just generate the point cloud quickly rather than wait to render I created a really fast mantra node that's 1x1 pixels that casts no rays, which only generates the point cloud.
just uncheck Images/Output/Create Image From Viewing Camera, it's there exactly for this purpose

ah true, thanks for the catch. that was pretty thick of me
Tighe Rzankowski

trzankofx@gmail.com
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