vex variables

[MENOZ]

hello, i'm trying to understand vex shaders.

in turbulent node vex node i have a P input parameter. what is it exactly?

should i put the P from global variables to P of turbnoise? if i do that my texture will not follow the surface of my object.

if u use S and T, with a float to vector node, i will have discontinuities on the seams.

can you help me please?

thanks!

[sibarrick]

You are so close...

P is just a point position that drives the noise.

Global P is the point position of the shaded point, BUT it comes in in camera space (or think of it as world space)

Use a transform vop to convert it to object space first then feed it to your noise vop. That should make it stick.

[MENOZ]

You are so close...

P is just a point position that drives the noise.

Global P is the point position of the shaded point, BUT it comes in in camera space (or think of it as world space)

Use a transform vop to convert it to object space first then feed it to your noise vop. That should make it stick.

so global P is looped along all the points of the surface, and at each point it return a different value.. and the noise function takes this vaule at each point to make his operations..

and this is also true for the S and T coords, i think.

because if i use a texture vop, and i feed it with a constant vop it generate stripes, because at each point being sampled, the texture vop alwais takes the same "position", so it return alwais the same value.

it's correct?

with a transform vop it works whe i render! thenks. but there is a way to stick the texture in the shader view too? it continue to be in camera space.

thank you!

[sibarrick]

so global P is looped along all the points of the surface, and at each point it return a different value.. and the noise function takes this vaule at each point to make his operations..

and this is also true for the S and T coords, i think.

because if i use a texture vop, and i feed it with a constant vop it generate stripes, because at each point being sampled, the texture vop alwais takes the same "position", so it return alwais the same value.

it's correct?

with a transform vop it works whe i render! thenks. but there is a way to stick the texture in the shader view too? it continue to be in camera space.

thank you!

correct

as for the shader view, I assume you mean the shader ball? yes from memory I think that never sticks.