u/Strong_Fox_3959

Hi

I'm making falling petals using vellum sim.

I scattered points on a grid, adjusted the pscale based on the camera distance, and used a copy to points node to instance the flower petal geometry onto those points.

Here is the issue: When pscale is set to 1, the petals look completely fine—no distortion, and the polygons look clean. However, when I scale down the pscale to 0.1 (to match my camera frame), the petals get heavily distorted, wrinkled, or bloated like in the attached screenshot.

https://preview.redd.it/9km15setftah1.png?width=483&format=png&auto=webp&s=7316b7b774451cb8d6f6498f06da1ba1dc5cc51f

^ pscale = 0.1

https://preview.redd.it/6omqife1gtah1.png?width=609&format=png&auto=webp&s=1284c09c88691905522f15c593ba0d160411c092

^ pscale = 1 (it's good)

https://preview.redd.it/w8754c1rftah1.png?width=691&format=png&auto=webp&s=5adf8fa783653a466c49656e4ce82a293035c25e

Has anyone encountered this issue before? Why does reducing the pscale value break the geometry like this, and how can I fix it?

Any advice or insight would be greatly appreciated. Thank you!

Hi,

I'm trying to use a mask attribute to drive the alpha/opacity of my geometry in Karma XPU.

It looks perfectly masked out and invisible in the Houdini viewport. However, as soon as I apply the MaterialX shader and render it, the alpha mask is completely ignored and the whole geometry renders as fully opaque.

https://preview.redd.it/729lueg17g4h1.png?width=800&format=png&auto=webp&s=24070bc3d5589ff7ea2813831a37fcd25840d586

alpha

https://preview.redd.it/tjtmdb3u7g4h1.png?width=1712&format=png&auto=webp&s=baa8ae97c9102aa0a50cb5bd67f73d97ee2e578b

https://preview.redd.it/26lep9h08g4h1.png?width=928&format=png&auto=webp&s=14b395443f6a5d1e3a1e962e4379946a88224bca

How do I make Karma XPU respect the point alpha attribute for material opacity?

Thank you for your help!

Hi

I'd like to export scatter mask and fire mask in Karma.

I can export these with pyro bake volume node, but I don't know how to do this in Karma.

https://preview.redd.it/u6sdx4rqrp1h1.png?width=353&format=png&auto=webp&s=af74e1125279f67ffe8db7f2ad30deff8c74c446

https://preview.redd.it/nb39e4dnrp1h1.png?width=696&format=png&auto=webp&s=50d411db68b176fb943d8321234b4b121a0e67d8

^ This is what I can see when I exported scatter and fire mask in Mantra.

I don't need to do manually as the pyro bake volume included this.

https://preview.redd.it/vjwzghawrp1h1.png?width=1197&format=png&auto=webp&s=c930e0c83a22c15527d77ff4a82c1d20145f6897

^ If I'd like to render and export the scatter_mask and fire_mask passes in Karma.

How to do this in karma explosion shader?

Thank you for your advice and help !

Hi

I'm struggled in the explosion rendering.

I watched tutorials and tried to play the explosion shader.

I'd like set up shader like this

my reference shader

my simulation

https://preview.redd.it/qi6is3t6641h1.png?width=1725&format=png&auto=webp&s=d292cdb569243474f55c2746f7e60203ae9c0e11

There are some screenshots about my set up

https://preview.redd.it/59rsvnv8641h1.png?width=996&format=png&auto=webp&s=794687bd61d77ed6cd4256112a66e9feba2a661b

https://preview.redd.it/xel4ehha641h1.png?width=1014&format=png&auto=webp&s=fd03ab5fa3187ca381c4678e2b13b60d9d228c5e

https://preview.redd.it/5jcr48pc641h1.png?width=1789&format=png&auto=webp&s=136c3cf2783cb273b7a805ed212930ff82b2741d

^ I linked pyro baked volume to material library in karma

I tried to adjust ramp and some parameters.. But I couldn't figure out how to look good and similar to my reference..

Thank you for your advice and help.

Hi

I'm trying to apply the material from a Pyro Bake Volume to Karma XPU, but it's not working properly.

When I use Karma XPU’s built-in pyro shader instead, the result looks quite different from the original Pyro Bake Volume.

Is there a proper way to transfer the Pyro Bake Volume shading to Karma XPU, or match the look more closely? Any tips would be appreciated.

pyro bake volume

https://preview.redd.it/gzhi2bzk1q0h1.png?width=1605&format=png&auto=webp&s=3e3f6691dd06d442d6332dc94532228ce808e0e2

https://preview.redd.it/2v83lywa2q0h1.png?width=1815&format=png&auto=webp&s=4ab05259d299df041a3f293b504edaccddc7af0f

^I tried to create and adjust pyro shader

https://preview.redd.it/nmtz0fdb2q0h1.png?width=730&format=png&auto=webp&s=e2147b1b619b4cf1ebe73efac63f5da7ba7c164e

https://preview.redd.it/2tuqk8qb2q0h1.png?width=777&format=png&auto=webp&s=7ec407ccdaba31f3eab23d32fcdec735ecea231b

In the Binding tab, it seems like scatter doesn’t work when the fields are left at their default values, so I tried changing the fields.

Thank you for your advice !