hi,

as the pic shows,

i really need the vector value of a point which is smooth, random(drive by some values) walking on sphere surface.

because of the odd of the noise function, now the path mostly appear on some area of the sphere,

plz help me,thank you very much.

you could try using the attribute noise vector node to randomize N or any other custom vector, set operation to "set" and use "zero-centered" so you get equally positive and negative values. then just normalize it, set it to the radius of your sphere and write to P

eaniix
you could try using the attribute noise vector node to randomize N or any other custom vector, set operation to "set" and use "zero-centered" so you get equally positive and negative values. then just normalize it, set it to the radius of your sphere and write to P

it really works!! thanks a looooot.

but still, because of my project, may i achieve this by not too complex VEX coding ?

You can remap the noise. Some noises have different output ranges, it's best to look it up in the Houdini documentation. The xnoise has an output range of 0-1, you would want a range from -1 to 1. to do that you can use a fit function


Insert that after you created the noise variables

If you have large enough time range, it should work:

vector2 u = 0;
u.x = xnoise ( @Time * 0.8 + ch("offset") );
u.y = xnoise ( @Time * 0.67 + 768.234 + ch("offset") * 1.7 );

vector p = sample_direction_uniform ( u );
@P += p;

eaniix
You can remap the noise. Some noises have different output ranges, it's best to look it up in the Houdini documentation. The xnoise has an output range of 0-1, you would want a range from -1 to 1. to do that you can use a fit function

a = fit01(a, -1, 1);
b = fit01(b, -1, 1);
 

Insert that after you created the noise variables

i c.
i will try this way, thanks a lot!

animatrix_
If you have large enough time range, it should work:

vector2 u = 0;
u.x = xnoise ( @Time * 0.8 + ch("offset") );
u.y = xnoise ( @Time * 0.67 + 768.234 + ch("offset") * 1.7 );

vector p = sample_direction_uniform ( u );
@P += p;

soooooo great!

animatrix_
If you have large enough time range, it should work:

vector2 u = 0;
u.x = xnoise ( @Time * 0.8 + ch("offset") );
u.y = xnoise ( @Time * 0.67 + 768.234 + ch("offset") * 1.7 );

vector p = sample_direction_uniform ( u );
@P += p;

one more thing, how to get this??
haha, always saw it, but never know how to get it.

hign

animatrix_
If you have large enough time range, it should work:

vector2 u = 0;
u.x = xnoise ( @Time * 0.8 + ch("offset") );
u.y = xnoise ( @Time * 0.67 + 768.234 + ch("offset") * 1.7 );

vector p = sample_direction_uniform ( u );
@P += p;

one more thing, how to get this??
haha, always saw it, but never know how to get it.

It's a custom Python Qt extension I wrote years ago. I talk about it in detail in this presentation (after 30 mins or so):

got it , the UI looks sooooooo elegant，love it.