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problems to render a spectral image

asked 2025-08-03 13:27:49 -0500

cy's avatar

updated 2025-08-09 10:53:07 -0500

Dear all,

As I continue exploring the new capabilities of Radiance, I found troubles trying to render an image with rtpict. The scene contains a sky (genssky) and a box-room, I started with an RGB typical simulation, however when I use spectral materials, only the sky appears in the scene, also, with rtrace and -pY I get a high value that correspond to the outdoors (I have a reference). Is like the geometry is not being considered in the rendering.

An example of what is in my materials file:

void spectrum spec_floor 0 0 22 380 780 0.1022 0.3293 0.3710 0.3772 0.3801 0.3815 0.3823 0.3813 0.3797 0.3784 0.3771 0.3763 0.3768 0.3787 0.3787 0.3797 0.3800 0.3797 0.3772 0.3770

spec_floor plastic floor 0 0 5 1 1 1 0

and to generate the image:

rtpict -vf view.vf -x 400 -y 400 -cs 20 -co+ specbox.oct > spec-box.hsr

Here are the two images I get: RGB (left), hyperspectral(right).

image description image description

I might be missing something obvious, but I can't find it. I'd appreciate any help! Thank you!

-Steph

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answered 2025-08-05 10:02:29 -0500

Dear Steph,

The issue is that you are using the modifier name rather than the "floor" material it modifies for the polygon, so it has no material. This is the same as a "void" surface, which will be present but invisible. Simply change the modifier on your polygon to "floor" and similarly fix your other surfaces so the scene will render correctly.

Thank you for being one of the first to exercise these new Radiance capabilities!

Best, -Greg

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I knew it was going to be something simple, thank you so much for your help!

cy's avatar cy  ( 2025-08-06 15:39:57 -0500 )edit

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Asked: 2025-08-03 13:27:49 -0500

Seen: 414 times

Last updated: Aug 09