Area light texture map?

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ioioio
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Joined: Tue Sep 17, 2019 7:45 pm

Area light texture map?

Post by ioioio »

Hello,

Does Luxrender support textures for area light?

So far these are the only available nodes for lights. Am I missing something?

Any help appreciated.
Annotation 2019-09-17 225155.png
PS. I'm using blender 2.8 with the luxcore beta4.
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B.Y.O.B.
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Re: Area light texture map?

Post by B.Y.O.B. »

Internally, an area light is the same as a plane with emissive material.
So you can use the latter in place of an area light and use any available node in the material node editor.

However, neo2068 has added support for textured area lights in 2.80, it should be included in the v2.2beta4 which you are using.
I have only briefly tested it though, I think there's a "Texture" panel in the area light options where you can select the texture node tree for the light.
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ioioio
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Re: Area light texture map?

Post by ioioio »

B.Y.O.B. wrote: Tue Sep 17, 2019 8:34 pm Internally, an area light is the same as a plane with emissive material.
So you can use the latter in place of an area light and use any available node in the material node editor.

However, neo2068 has added support for textured area lights in 2.80, it should be included in the v2.2beta4 which you are using.
I have only briefly tested it though, I think there's a "Texture" panel in the area light options where you can select the texture node tree for the light.
Thank you for your reply.

I try to avoid using mesh lights because they are harder to control and seem to have noisier results.
I should have been more clear on this. My issue is I can't seem to control the UV for the area light. With Cycles I can add a Geometry node but this seems to be missing with Luxrender.

Here's what I mean. While the light does show up as an overall magenta color, the checker texture is not visible on the cylinder's surface. I fiddled with the values in the 2d mapping node but they don't seem to do anything.
Annotation 2019-09-20 142839.png
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B.Y.O.B.
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Re: Area light texture map?

Post by B.Y.O.B. »

Good catch, the area light mesh is currently defined without UV coordinates.
https://github.com/LuxCoreRender/BlendL ... ht.py#L401
ioioio wrote: Fri Sep 20, 2019 11:38 am I try to avoid using mesh lights because they are harder to control and seem to have noisier results.
In LuxCore, an area light is literally a mesh light. So one can't be noisier than the other when their settings are identical.
Can you upload a small scene showing the problem, maybe it's a bug of some kind?
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ioioio
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Re: Area light texture map?

Post by ioioio »

Sure. I just used a 2D checkerboard in this one and it seems only the first color is registered for some reason.
Studio Lux.blend
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EDIT. I just tried the mesh light method and works great. Since Cycles has a different way of handling lamps than meshes with emission nodes I just assumed Luxcore would be no different.

Thank you.
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