Forums Technical Discussion Antialiased Flow Noise in VEX or SOP

Antialiased Flow Noise in VEX or SOP

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PaoloGiandoso
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Hi
Is it possible to exactly replicate the animated Antialiased Flow Noise VOP using VEX ot the Attribute Vector/Flow Noise SOP?
Or is a VOP absolutely necessary?
Edited by PaoloGiandoso - Aug. 31, 2024 18:13:51
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animatrix_
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Hi,

You can do this in VEX easily:

#include <voptype.h>
#include <voplib.h>

vector noise = vop_fbmFlowNoiseVV(@P * chv("freq") - chv("offset"), ch("rough"), chi("maxoctave"), ch("flow"), ch("flowrate"), ch("advect"));
noise *= ch("amp");

@P += noise;

Senior FX TD @ Industrial Light & Magic
Get to the NEXT level in Houdini & VEX with Pragmatic VEX! [www.pragmatic-vfx.com]

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PaoloGiandoso
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animatrix_
You can do this in VEX easily
THANKS! This is super useful!
Anything with the Attribute Vector/Flow Noise SOP?
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animatrix_
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PaoloGiandoso
animatrix_
You can do this in VEX easily
THANKS! This is super useful!
Anything with the Attribute Vector/Flow Noise SOP?

AA Noise SOP uses Unified Noise - Static VOP which uses pyro_noise.h. AFAIK vop_fbmFlowNoiseVV is not available this VOP.
Senior FX TD @ Industrial Light & Magic
Get to the NEXT level in Houdini & VEX with Pragmatic VEX! [www.pragmatic-vfx.com]

youtube.com/@pragmaticvfx | patreon.com/animatrix | pragmaticvfx.gumroad.com
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PaoloGiandoso
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animatrix_
AA Noise SOP uses Unified Noise - Static VOP which uses pyro_noise.h. AFAIK vop_fbmFlowNoiseVV is not available this VOP.
Apologies I can not understand what you mean. Could you rephrase it?
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jsmack
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animatrix_
PaoloGiandoso
animatrix_
You can do this in VEX easily
THANKS! This is super useful!
Anything with the Attribute Vector/Flow Noise SOP?

AA Noise SOP uses Unified Noise - Static VOP which uses pyro_noise.h. AFAIK vop_fbmFlowNoiseVV is not available this VOP.

The vop fbm flow noise wrapper is a wrapper for the flownoise VEX function. Pyro noise also has a wrapper for flownoise, exposed on the unified noise vop as 'perlin flow'.

Unified noise has different scaling, and the wrapper is different from the voplib one, so they won't match exactly, at least not without reverse engineering the exact offsets and scales to make them match.
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PaoloGiandoso
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If I understood correctly, there is no way to replicate the AA FlowNoise in the the AA Noise SOP
Also, AAFlowNoise and FlowNoise VOPs are wrappers for the flownoise VEX function, did I get it right?

jsmack
Pyro noise also has a wrapper for flownoise, exposed on the unified noise vop as 'perlin flow'.
Thanks!
What do you mean with Pyro Noise? When I create an attribute VOP I see 2 nodes called unifiedNoise and UnifiedNoise_Static. They both have a Noise Tyepe called "Perlin Flow" available. Does it mean that both these nodes set to "Perlin Flow" are also a wrapper for the flownoise VEX function?

The AAFlowNoise is so useful that I am puzzled sideFx has not added it to a SOP already.
Edited by PaoloGiandoso - Oct. 30, 2024 19:39:40
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