# Rotation per point.

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Hi.

I know this is basic question, but...

Somebody tell me how rotation is stored per point in copy point sop. I see there are couple ways.

First method by normal vector, second one by orient parameter.

I'm confused when I want to rotate packed and instanced object arround Normal vector.

Somebody know how to to this in Vop or Vex?

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Here's one way - the switch toggles between using a normal pointing up and using the tangent of the path. Press play and you'll see they rotate around the normal.

The offset parameter is just there to give you a way of rotating them differently along the length of the path. The curveu attribute that it's using for the offset is output by the second resample SOP.

orient.hiplc

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Thx Jooey but what if I have for example a sphere?

In my case I have model of statue where are points not on one plane.

I want to control rotation only around point normal, or chosen local axis. Rest of the axis should be intact + a little random rotation for each of the rotations.

I don't know how to rotate initial rotation from copy point. Look at my red example there are everything fine for initial rotation for cubes. But If you switch to blue you see that there

is rotate by axis and is almost perfect. But i don't know how to multiply this transformation by initial transformation.

Should I transform somehow vector to quaterion. But how if I only have position and normal vector and didn't have a rotation angle?

copy_normalOrient.hipnc

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Probably this problem is very trivial. But I stuck.

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Thanks. This is perfect. I was thinking that those additional vectors are stored somewhere.

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Ah, no you have to compute them. You can also do that with the PolyFrame SOP, I'm just in the habit of using a wrangle.

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