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Using Noises in World Space

Posted: Wed Oct 17, 2012 10:44 am
by Behrendt
Hey there,
after using V-Ray for C4D for about 3 years now I want to give Indigo another try. I already used it way back in 2006, so it has been a while, so please excuse me if I ask some stupid questions.
From V-Ray I'm used that nearly all C4D shaders are natively supported. So, if I use a noise shader in world space and apply it to a infinite plane (for indigo lets say a reaaaaaaaaly big plane) I don't get any pattern repetition across the surface (as its supposed to be). When rendering with Indigo I get these patterns, as I think noise is baked using the texture tag and the values specified there. So if I map the noise with cubic mapping and a size of 100x100x100cm I only get a unique pattern for 100x100x100cm. This would be correct behaviour for texture space I think. Also if I resize the mapping to 200x200x200cm the noise also is scaled up. When working in world space this shouldn't happen. The noise size in world space should only be specified by the global scale in the noise settings.
Is there ANY possibilty at all to prevent this behaviour and get random noise across the whole surface in Indigo with C4D shaders?
I think a workaround for this behaviour would be really benefitial and essential for creating advanced shaders in C4D.
Kind regards
Christian

Re: Using Noises in World Space

Posted: Wed Oct 17, 2012 5:34 pm
by Zom-B
baking noise shaders does have this issue, no Idea if there can be something done :(
I'm quite interested how Vray worked that out... could be that they simply "share" the same noise code, or does Vray bake to texture too?!

Only hint I can give you here is that there are some ISL shaders in C4D, but the "ISL Noise" Shader only uses perlin and FBM att the moment...

Re: Using Noises in World Space

Posted: Wed Oct 17, 2012 8:49 pm
by Behrendt
I'm 99,9% sure V-Ray does it without baking the noise into textures. As V-Ray in the end also needs the V-Ray Core to render the scene I think it should somehow be possible for Indigo too. But I also know the V-Ray integration is very deep and needed a lot of work. For sure this is no trivial task, but I think a deeper integration into the host app is always good.

Re: Using Noises in World Space

Posted: Wed Oct 17, 2012 9:17 pm
by OnoSendai
Hi Behrendt,
Indigo certainly supports noise shaders based on world space position, so it's a matter of CIndigo exporting it.

Re: Using Noises in World Space

Posted: Wed Oct 17, 2012 9:47 pm
by fused
OnoSendai wrote:Hi Behrendt,
Indigo certainly supports noise shaders based on world space position, so it's a matter of CIndigo exporting it.
You are making it sound a bit too easy, Nick :)


Behrendt:
Supporting C4D shaders without baking (either by translating to ISL or somehow using them directly) is certainly possible and I have thought about implementing this quite often. For now, the only way to get proper world space noise is to use the ISL Noise shader that comes with Indigo for C4D.

Re: Using Noises in World Space

Posted: Wed Oct 17, 2012 9:52 pm
by Behrendt
Sadly my coding knowledge is to small to really evaluate this. But how would it theoretically work that Indigo supports Cinemas internal noise shaders? I would be really happy if this could work somehow, as there are also some other shaders which really would be of great use if supported properly (Tiles shader for example also).
And as V-Ray seems to handle it I think it might be possible somehow. Looking forward to hear from you. :)
Could I also get access to the SDK-Forums as well?
@fused
I would really appreciate it if you could have a look into using them directly, just to evaluate how difficult it would be to implement it. I think it would be really useful, as nearly all my shaders make somehow use of this in order to prevent noticable texture tiling, which imo is very important for good ArchVis.

Re: Using Noises in World Space

Posted: Wed Oct 17, 2012 11:48 pm
by Mor4us
Hi Christian,
nice to see you here on board as indigo user!
Looking forward to see your first progresses with indigo ;)

regards