Rotation with a Copy SOP on curve

[Homer0]

Hi all, i've a question about the Copy SOP.

Let's say i've a simple Box, plugged into a Copy with a curve as second input. It copy the box along the curve points, and i take care of the orientation with a Polyframe. Now i want the Box to have an incremental rotation on the Z axis every copy.

Without a second input, i could manage that with the Rotate of the copy keeping Transform Cumulative turned on; but with a second input plugged in, it doesn't work... any suggestion?

 

Thanks in advance ^^

[Atom]

That is what stamping is for. On input 2 add an attribute wrangle which runs over the points of the curve. Create a new attribute called my_rotation for each point. Then stamp that information into a transform that you also add to input 1.

Edited November 15, 2016 by Atom

[Homer0]

wow, thanks but at the current state of my houdini learning this sound way too complicate.

[Homer0]

alright, so far i got it how to stamp the attribute. I created my_rotation, gave it a 20 as value and then, into a transform added on the first input, i wrote in the Rotate Z: stamp("../copy1","my_rotation", 0)

The attribute works, but it rotate every instance with the same value, guess it's the Attribute Wrangle part missing, which i suppose i need to tell that every point in the curve have to get a differente value....

 

EDIT: I finally did it. Since i wanted every instance rotated by 15 degrees, i just put 15*$PT as Value of the Stamp attribute. I probably didn't make myself clear and  @Atom thought i needed something more complex ^^

Edited November 15, 2016 by Homer0

[acey195]

if at some point performance becomes an issue (if you are dealing with > millions of points) the fastest approach would be by pre-modifying the normals on the right input.
This does require a bit of vector math to get right though.

[Werner]

Use Attribute Randomize on the second input. This will create any attribute (like pscale, orient, v, Cd) to the incoming points before the copy actually happens.

Edited November 24, 2016 by Werner