Sure thing but be warned that I'm far from being a noise expert! :)
On 27 April 2017 at 17:21, Andy Nicholas <a...@andynicholas.com> wrote: > Yes, exactly, I found the same. I'm quite relieved your experience mirrors > mine as otherwise I've just been wasting a lot of my time! :) > > Would love you to beta test when it's ready (if you're interested). > A > > > On 27/04/2017 11:17, Christopher Crouzet wrote: > > I've just tried what you said and in fact the unified noise doesn't even > seem to use the full [0, 1] range as one would expect from reading the doc. > At least not in H13. Or maybe I did something wrong. If this turns out to > be true, it'd kill the primary purpose of the node to bring coherency > between the different noise types. Not great for lookdev as you said. > > This bring back blurry memories where I digged into the unified noise a > couple of years ago and ended up coding my own, maybe because of this exact > reason. But then I eventually lost the digital asset that I had built and > ended up using the default noises instead :) > > > On 27 April 2017 at 16:42, Andy Nicholas <a...@andynicholas.com> wrote: > >> The `Unified Noise VOP`, which is a fairly useful node that outputs all >> the noise values in the [0, 1] range, takes pretty much all of its logic >> from the `pyro_noise.h` include file. Which means that you can easily have >> access to the same functionalities in VEX, like so: >> >> #include <pyro_noise.h> >> v@perlin = vnwrap_perlin3(v@P, 0, 0); >> f@pflow = fnwrap_pflow1(v@P, {1, 2, 3}, 0); >> >> >> >> Aah, thanks for that Chris. Didn't realise you could access the noise >> functions like that. Good to know :) >> >> Also, it's interesting to see how they managed to unify the noise values >> in `pyro_noise.h`: they basically ran a lot of samples and picked the >> min/max values of each noise to approximate their range. Statistics for the >> win! :) >> >> >> Yep, that's what I've been doing. I'm concentrating on FBM modes of >> evaluating the basic noise functions (noise(), xnoise(), snoise(), >> onoise(), anoise) as that's what I tend to use the most. Unified Noise is >> okay, but I still find problems with shifting offsets in the noise. >> >> For example, make a grid with 150 divisions, create a Unified Noise in a >> Point VOP and set it to use Signature:->"3D Input, 3D noise", Noise >> Type->"Perlin", Fractal Type "Standard (fBm)" add the vector output to the >> point position and then try playing around with the Max Octaves, >> Lacunarity, and Roughness. You'll see that you get a global uniform "DC" >> offset along the each axis. That's not cool! If I'm using that as a noise >> force, then it has just pushed all my particles in the (1,1,1) direction. >> You'll also find that switching between noise types noticably changes the >> amplitude range. Again, not great if I'm doing lookdev and I just want to >> try a different noise type without changing the general magnitude force >> amount. >> >> In addition to sampling the noise values, I'm doing some curve fitting to >> that data in Python's scipy which smooths out some of the statistical >> glitches with the sampling. It's giving some good results that don't >> exhibit the DC offset that I mentioned above. All this should let me create >> a replacement for the Anti-Aliased Noise VOP. I'm not dealing with the >> anti-aliasing aspect yet though, so it won't be as good for shaders, but >> the offset isn't quite so important in that context as it is for using it >> for forces. >> >> Still need to do some testing and then package them up into VOPs, but >> once they're ready I'll release them in siLib for everyone to try. >> >> A >> >> >> >> ------ >> Softimage Mailing List. >> To unsubscribe, send a mail to softimage-requ...@listproc.autodesk.com >> with "unsubscribe" in the subject, and reply to confirm. >> > > > > -- > Christopher Crouzet > *https://christophercrouzet.com* <https://christophercrouzet.com> > > > > ------ > Softimage Mailing List. > To unsubscribe, send a mail to softimage-requ...@listproc.autodesk.com with > "unsubscribe" in the subject, and reply to confirm. > > > > ------ > Softimage Mailing List. > To unsubscribe, send a mail to softimage-requ...@listproc.autodesk.com > with "unsubscribe" in the subject, and reply to confirm. > -- Christopher Crouzet *https://christophercrouzet.com* <https://christophercrouzet.com>
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