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Falloff texture

Posted: Sat Jan 11, 2020 10:37 am
by lacilaci
Can we get a falloff node/texture? I would like to control object glossiness at glancing angless with this for example.

(to simulate what fstorm does with "angle affect" feature, or what Thea render does with it's micro roughness controls)

Re: Falloff texture

Posted: Sat Jan 11, 2020 5:37 pm
by Dade
This sounds more like a material than a texture (at least in the framework of how LuxCore works).

I don't think to touch anything in materials before the rework (the one to avoid dynamic code generation and kernel re-compilation for OpenCL). It is a basic step before to add anything new.
Disney 2015 addition may the only exception because our 2012 version is somewhat "incomplete".

Re: Falloff texture

Posted: Sat Jan 11, 2020 5:51 pm
by lacilaci
Dade wrote: Sat Jan 11, 2020 5:37 pm This sounds more like a material than a texture (at least in the framework of how LuxCore works).

I don't think to touch anything in materials before the rework (the one to avoid dynamic code generation and kernel re-compilation for OpenCL). It is a basic step before to add anything new.
Disney 2015 addition may the only exception because our 2012 version is somewhat "incomplete".
Well yes this could be an additional control straight in Disney. Changing the ratio of how is object becoming glossy at glancing angles. Not sure how much is this physically plausible but it's a popular thing in fstorm and was requested several times on Corona forums and for cycles too. Consider this an artistic tweak like the sheen, where it might make some materials more convincing looking in some cases.

Re: Falloff texture

Posted: Sun Jan 12, 2020 11:13 am
by PetrT
why not as geometry data node like hitpoint node now?
try to use shading normal with dot product but it must be allways faced to camera
may be it easier to use camera data node with some vector math and shading normal of object

may be the way of reusing Cycles node(Layer Weight) is exist-?

Re: Falloff texture

Posted: Sun Jan 12, 2020 11:50 am
by CodeHD
PetrT wrote: Sun Jan 12, 2020 11:13 am may be the way of reusing Cycles node(Layer Weight) is exist-?
I was thinking of using the Fresnel node to mix two materials, which i recall from a while back.
But I just looked at it again, and the output type doesn't seem to match anything? Am I missing something?

Re: Falloff texture

Posted: Sun Jan 12, 2020 12:06 pm
by lacilaci
Oh for future reference it seems it's called glossy fresnel now

Image from manual
IMG_20200112_130429.jpg
Mixing 2 materials might be too expensive computationally.

Re: Falloff texture

Posted: Sun Jan 12, 2020 3:43 pm
by B.Y.O.B.
CodeHD wrote: Sun Jan 12, 2020 11:50 am I was thinking of using the Fresnel node to mix two materials, which i recall from a while back.
But I just looked at it again, and the output type doesn't seem to match anything? Am I missing something?
The LuxCore fresnel node is only for metal fresnel data (n and k parameters) and can only be used on the metal material node.
It's a bit of a weird little thing.

Re: Falloff texture

Posted: Thu Jul 02, 2020 8:29 am
by MetinSeven
I'd also very much welcome a falloff node that allows you to mix two colors, textures or materials based on the viewing angle (perpendicular vs. parallel), with an adjustable range.