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Dominic Brown avatar image
Dominic Brown asked ·

Fireflies and artefacts with Camera Radial distortion type to cubic_inverse

Hello, I have weird fireflies and artefacts when I use the Radial distortion type "cubic_inverse" in the Arnold tag of the camera. No problem with the "cubic" type.

Here is my setup:

output image 1625x795 pixels

Camera: focal length 12 mm, 36 mm sensor

Arnold tag: Radial distortion 0.13, Radia distortion type "cubic_inverse", Lens tilt angle 9degrees on the Y.


I'm looking for the widest image with the lowest amount of distortion possible. When I use this setup, a long purple sort of light leak appear in the render. Is there a workaround or a trick on the settings?

cubic_inverse type:


cubic type:

c4dtoa
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Peter Horvath avatar image
Peter Horvath answered ·

The issue is a combination of the cubic_inverse radial distortion and flat projection on the normal map. A possible workaround until the fix is to generate the uvw from the texture tag (Right click -> Generate UVW Coordinates) and use that uv map for shading.

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Dominic Brown avatar image
Dominic Brown answered ·

Sure, here is the file with only one material, physical sky and two camera with the described settings. (because it said "Denied" on the file uploader, I've made you a wetransfer link here: https://we.tl/t-4O7ZlV6Gx6 )

wetransfer link

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Thanks, I can reproduce it with your scene. I'm investigating.

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Peter Horvath avatar image
Peter Horvath answered ·

I was not able to reproduce it. Can you send me a simplified scene maybe?

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