I found the Unified noise slower than the other noises. No ?
2017-04-27 11:42 GMT+02:00 Andy Nicholas <a...@andynicholas.com>:
> 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
>
>
>
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