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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