Aliased Alpha in OpenGL render

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Hello!

Is there an approach that yields correctly anti-aliased renders for Alpha values lower than 1 from the OpenGL rop?

I've animated the point attribute 'Alpha' on a piece of geometry from 0 to 1 over time. When the value is 1, the antialiasing in the render is correct. Any lower value presents aliased, jagged edges in the C and Alpha channels. I have tried the following:

- increasing AA in display options in the openGL ROP
- tried rendering to .exr instead of .png
- set Antialiasing - Transparency in the Nvidia Control Panel to 8x
- tried rendering in Mantra which solves the issue but takes a very long time
- tried with and without a principled shader assigned to the geometry

Thanks very much,

Ryan
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It's probably best to move on. That is legacy technology. Try the Karma ROP.
Using Houdini Indie 20.0
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When the Transparency is set to Medium or High, samples are used to collect different layers of depth rather than coverage. You can decrease the quality to Low if you don't have layered transparent surfaces, and you'll get antialiasing back.
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Thanks very much malexander, changing the quality to low addressed this issue. I would never have guessed this behavior!
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Wow, that's a great tip. Turn it down to turn it up.
Edited by Enivob - 2024年6月3日 08:06:05
Using Houdini Indie 20.0
Windows 11 64GB Ryzen 16 core.
nVidia 3050RTX 8BG RAM.
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