Getting Parallel Light with Distant in Solaris

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Anyone know how one can get parallel light when the light node is set to Distant, the same way as you can with an object light set to Distant for Mantra?

When I set the Solaris light node angle parameter to 0, no matter how much I crank up the exposure nothing gets illuminated at such an angle.

I'm guessing the way Solaris is set up now and someone wants that, they just have to go with a rectangle light and make it large enough to spread across the objects desired to be lit the same way.
Edited by BabaJ - Aug. 31, 2021 11:21:11
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Anyone know how one can get parallel light when the light node is set to Distant, the same way as you can with an object light set to Distant for Mantra?

The distant light is always parallel. Do you mean no soft shadows? I don't think there's a way to have an angular size of 0, but you can set it really small.

BabaJ
I'm guessing the way Solaris is set up now and someone wants that, they just have to go with a rectangle light and make it large enough to spread across the objects desired to be lit the same way.

That sounds like the opposite of what you want. If you want a point light with parallel rays, you could create a point light and put it sufficiently far away.
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The distant light is always parallel. Do you mean no soft shadows? I don't think there's a way to have an angular size of 0, but you can set it really small.

Actually, it isn't - Unless there is a bug.

That sounds like the opposite of what you want. If you want a point light with parallel rays, you could create a point light and put it sufficiently far away.

Don't know why you would think it is the opposite. I've gone with the rectangle light and oversized it pass the objects boundaries. It is giving me the same centered highlights I was hoping for with the distant light(which it didn't, acting like a point source instead). Yeah, a point light far away would do the trick, but if I remember last time I tried that you really have to crank up the exposure.
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Actually, it isn't - Unless there is a bug.

Maybe it stole the code from the mantra sun light that is also not parallel but simply 'far away'. I haven't done tests evaluating that.

BabaJ
Don't know why you would think it is the opposite. I've gone with the rectangle light and oversized it pass the objects boundaries. It is giving me the same centered highlights I was hoping for with the distant light(which it didn't, acting like a point source instead). Yeah, a point light far away would do the trick, but if I remember last time I tried that you really have to crank up the exposure.

A giant rectangle isn't going to give parallel rays, but rays going every direction. I'm not sure what you're after, as the distant light is more or less like a point source, depending on the solid angle.
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Now I've tested it. The distant light is always parallel, and doesn't have the same problem that the sunlight has in mantra. Also, setting angle to 0 has the expected effect of making shadows perfectly sharp.

Attachments:
dist_test.jpg (387.0 KB)
distant_light_test.hip (347.5 KB)

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The issue was the camera was set to perspective instead of ortho.

But the real issue is Houdini not updating render or scene view often enough to reflect the parameters settings you have leading one to think your results are a reflection of your settings and making you think they work one way but they don't.


e.g. That bottom image is mantra with camera set to ortho. Yet earlier the camera(mantra) was set to perspective and gave the same bottom view. (The top view is karma with camera set to perspective).
Edited by BabaJ - Aug. 31, 2021 20:19:08

Attachments:
Parallel.png (100.7 KB)

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