BlendLuxCore Development

Discussion related to the LuxCore functionality, implementations and API.
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B.Y.O.B.
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Re: BlendLuxCore Development

Post by B.Y.O.B. »

Dade wrote: Mon Mar 11, 2019 2:38 pm Well, do the Dot() inside the texture if you have but don't add a field to HitPoint object (i.e. GPU memory usage).
I don't need the extra field on the GPU because Bidir doesn't work on the GPU (I can just use fixedDir there because it's always the camera vector).
Dade wrote: Mon Mar 11, 2019 2:38 pm how you are supposed to know the camera dir while tracing paths from the light sources (i.e. BiDir, PhotonGI, etc.) ?
I thought I could maybe calculate
cameraDir = camera.position - hitPoint.p;
Can I check the camera position when initializing hitPoint?
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Re: BlendLuxCore Development

Post by Dade »

B.Y.O.B. wrote: Mon Mar 11, 2019 2:51 pm I thought I could maybe calculate
cameraDir = camera.position - hitPoint.p;
Can I check the camera position when initializing hitPoint?
Uh ? Can you recap of what we are talking about ? I have lost you.

An HitPoint is the result of a ray hitting a surface or of a volume scattering event. Most of the times a ray doesn't come from a camera (i.e it comes form a light source, another hit point, another volume scattering event, etc.).
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Re: BlendLuxCore Development

Post by B.Y.O.B. »

Yes, I was wrong, taking the camera dir is bullshit.

I think this kind of texture can only work in a unidirectional pathtracer, as you said it makes no sense for a lighttracer.
In my opinion this means it shouldn't be added at all, inconsistency between engines is bad.
@Sharlybg the dust effect you mentioned is possible without this by the way, for that you only need Dot(hitPoint.shadeN, Vector(0, 0, 1)).

Here is the result of

Code: Select all

Dot(hitPoint.shadeN, hitPoint.fixedDir)
for pathcpu, lightcpu, bidircpu and cycles:
Attachments
path
path
light
light
bidir
bidir
cycles (ignore light brightness differences)
cycles (ignore light brightness differences)
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Re: BlendLuxCore Development

Post by Sharlybg »

It doesn't work on light cpu. so we are not going to be able to tweak this viewport render ? how reproduce it in blendluxcore node system ;)
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Re: BlendLuxCore Development

Post by B.Y.O.B. »

Sharlybg wrote: Mon Mar 04, 2019 10:15 am
I guess for dust you would need the world Z coordinate as input instead of the camera direction? So an arbitrary normal input like in Cycles' fresnel node would be good.
I'm not a great expert about the tech behind such kind of things. I mostly don't like too complexe shader node to achieve basic natural effect.One of the reason i don't like cycles node system and node tricks.I think tools should allow artist to concentrate on art . So my point is that if you can yourself produce this effect (the principle) with luxcore node system and provide us the how to do i'm ok ;)
The dust effect you wanted is now possible in v2.2alpha1.
You will need two of the new nodes from the "Utils" category: Hitpoint Info and Dot Product.
Then you can create a setup like in the attached images.
(Rhino model from http://threedscans.com/depot-des-sculpt ... ris/rhino/)
Attachments
1.PNG
2.PNG
rhino.jpg
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Re: BlendLuxCore Development

Post by B.Y.O.B. »

Played around a bit more. You can control the falloff of the dot product with the new "power" option in the math node.
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3.PNG
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Re: BlendLuxCore Development

Post by provisory »

👍
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Re: BlendLuxCore Development

Post by lacilaci »

Dust looks nice but I think a proper AO/dirt map with controls over distance and mapping(for variation) is needed for better dirt distribution (also with possibility to select self contact only or the whole scene)
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Re: BlendLuxCore Development

Post by epilectrolytics »

Thanks for the new nodes/functions, much appreciated!
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Re: BlendLuxCore Development

Post by Sharlybg »

Like you , you know ? :D

thanks you very much !
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