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
>>
>>
>>
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>
>
>
> --
> Christopher Crouzet
> *https://christophercrouzet.com* <https://christophercrouzet.com>
>
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Christopher Crouzet
*https://christophercrouzet.com* <https://christophercrouzet.com>
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