Position(object) applied noise on Particles

[Torbach78]

[static Mesh on left. Mesh render in Shuriken on right]

I used a revolved plane and project Voronoi noise + panning perlin noise to create distortion

I am applying both noises with Position{object} rather than a UV node so that its seamless
just like detailed by this thread

Help In Understanding Simple Noise Node UV Input in Shader Graph

Hey, so basically think about it like this: UV space is like a 2D rectangle. Visualizing it helps So a spot on the left most side will have a different U value than a spot on the right most side, because of the distance between them. When we “wrap” a 3D object with a UV map sprite, the left most spot and right most spot from before are now touching. So in (3D) Object Position they are indeed very close to each other, but in (2D) UV Position their U values are still very differen…

Position>Object → UV on noise nodes in shadergraph works great on static mesh

I really wanted to utilize the technique with particles

I can understand that the position expects a plane of existence otherwise it smears… but the panning speed I have and the simple noise (used to distort) is going bonkers on the particle and the scale seems a lot larger but in odd contrast the pan speed seems blown up exponentially.

how or what is happening? how could I normalize or correct this problem (without flattening the noise into a texture)
or perhaps re-project noise using a different way

[richardkettlewell]

Could it be related to the fact that shuriken particle data is always transformed into world space before it gets to the shader? (position, normal, tangent)

[Torbach78]

@richardkettlewell

Could it be related to the fact that shuriken particle data is always transformed into world space before it gets to the shader? (position, normal, tangent)

Oh yah! I checked to see if particles and meshs are identical using World position input and they match 1:1

[Torbach78]

ok thanks @richardkettlewell very helpful.

Work-around (afaik) is cross-product matcap technique - minimize screen swimming and projects view confined to object bounds

• it works with mesh and billboarding alike, even with world-based rotation.

satisfactory test results so far, imho

view based distortion remains seamless

• partners with UV space operations
• allows access to rotations
• non-proportional scale to perturb ratio on local level

[richardkettlewell]

wow that’s really nice!

[NG_Seiberling]

@Torbach78

ok thanks @richardkettlewell very helpful.

Work-around (afaik) is cross-product matcap technique - minimize screen swimming and projects view confined to object bounds

• it works with mesh and billboarding alike, even with world-based rotation.

satisfactory test results so far, imho

view based distortion remains seamless

• partners with UV space operations
• allows access to rotations
• non-proportional scale to perturb ratio on local level

Super cool! I didn’t know there was a work around for this. Can you share a graph?

[Torbach78]

hey material capture is analogous to an old environment map ----locked to view around the object rather than world.

BGolus had a great crossProduct version here

I think I put it in ShaderGraph like this at the time (<-- this snip is makes the UV’s for noise/texture applying)

[NG_Seiberling]

@Torbach78

hey material capture is analogous to an old environment map ----locked to view around the object rather than world.

BGolus had a great crossProduct version here

I think I put it in ShaderGraph like this at the time (<-- this snip is makes the UV’s for noise/texture applying)

Brilliant! Thanks mucho for the help!