Hello;

I copied several geometries on a grid, using “Copy to Points” SOP and “For each loop”…
All copies have same Transforms, so how can I rotate each piece randomly?

(I attached my scene here)


Thanks.

Use an Attribute randomize on the points before the copy SOP. Set the attribute inside to pscale or orient

Hi Werner Ziemerink;
I did but nothing changed …!

put a pointwrangle node above your foreach loop and
type this to get what you want


copy to points will rotate the copied geos based on certain attributes present in the template points such as N v and orient. I would suggest the best to use is orient, But N is simple it will align the z axis of your source geo to the normal of the template points

Read the below page to know how houdini aligns the instanced objects
http://www.sidefx.com/docs/houdini16.0/copy/instanceattrs [sidefx.com]


you can add attribute randomize to the template points before copy sop like werner says and you should change the dimension to 4 in the attribute randomize sop as orient is a 4float attribute.

This must be one of the most asked questions I see about Houdini, probably because it's one of the more common workflows. It really is time that we get a node for taking care of the various transforms and their randomization's we tend to do when copying.

edit: actually a masterclass on setting something like this up would be a good intro into the workflow of houdini.

Thanks everyone.

Thank you Mohanpugaz,
“PointWrangle ” and “Attribute Randomize” works fine.
I'm wonder why “Attribute Create” with same configurations doesn't works!

Masoud
Thanks everyone.

Thank you Mohanpugaz,
“PointWrangle ” and “Attribute Randomize” works fine.
I'm wonder why “Attribute Create” with same configurations doesn't works!

Hello dude.
Yes, it shouldn't work because the type of the orient attribute is vector 4 (Quaternion) not just ordinary vector which has 3 components.
Therefore in attribute create node set the type to float and set the size to 4.
Now you should see something…

you can randomize @N within randomize attribute SOP inside a sphere

I did the following for random rotation in the attribrandomize Node

....

Attribute Name: orient
Operation: Set Value
Distribution: Direction or Orientation
Dimensions: 4

Hope that helps a newbie like me somewhere...

Fwiw there is the `scatter and align` node now built in for doing random rotation along normals

I just installed Houdini, watched first tutorial lesson, and wanted to add extra rotation to donuts falling down. Came here to find an answer. I've added new attribute randomizer node and didn't know what attribute name to put. Don't know how you folks know those. I am sure there is a way to find out all the available attribute. I expected a dropdown or smth, but it wasn't there. Anyway, this thread helped - it's `orient`, but also it needs 4 values. But! It seems like this property is a quaternion, which means if i want to restrict rotation to some axis I would need to get a PHD to understand how quaternions work.
But! I was playing a bit and found that You can change `distribution` parameter to "Direction or orientation" And there is a `Cone Angle` Slider that kinda does what I wanted (though I still don't know what it does exactly.
Anyway, I thought next person like me might enjoy this discover to make falling dunuts a bit more fun.

If you want to apply rotation around specific axes to existing points (meaning Scatter and Align isn't exactly what you need), you can use MOPs Randomize SOP to do local or world random rotations.

The manual way to do it is with a bit of VEX. First you create a transform matrix or quaternion based on your existing N and up values, then you rotate that matrix or quaternion, then output to p@orient or 3@transform (or @N and @up) depending on your preference.

that instanced geo link on SideFX is now here: Copying and instancing point attributes [www.sidefx.com]