Hi Curt, did you look into the hole SOP?

There is a Kelvin Wakes deformer in SideFX Lab's now: https://www.sidefx.com/docs/houdini/nodes/sop/labs--kelvin_wakes_deformer-1.0.html

How would you blend positions between meshes with different topology and uneven point count? My idea was to use the 'underlying' primitive's intrinsic UV coordinates for matching. But when transfering to world position I run into this typical "fix boundary seams"-issue known from the UV texture-node. blend_pos.hip

Polyextrude does UVs. Just assign UVs on the grid in advance and ignore the viewport issue that comes later. extrude_uv.hip

VEX version: float t = chf('threshold'); v@P.y = -abs(v@P.x - t) + t;

Hi Dana, I'd recommend to look into the sweep node again. It accepts pscale and scale attributes for varying widths, creates UVs and has lots of other useful features such as creating primrow and primcol attributes eg. for lanes.

The Labs Straight Skeleton 3D node creates curves through the middle: https://www.sidefx.com/docs/houdini/nodes/sop/labs--straight_skeleton_3d.html

Handling per object-rotations gets easier after packing and instancing the copies. Eg. the primitive node can do random rotations afterwards. copies_rotate.hipnc

Hi Apurba, presumably by setting the cluster node to 6?

You would usually define the point orientation before copying objects to them. The normal vector "N" pointing to the front and the up vector "up" pointing upwards, eg. perpendicular to the surface. Next you can rotate the up vector around the normals using a point wrangle. float amount = chf('amount'); matrix3 m = ident(); rotate(m, amount * M_PI, v@N); v@up *= m; There are many other ways and as per usual Matt's CG wiki has a good read on this: https://www.tokeru.com/cgwiki/index.php?title=JoyOfVex17 rotate_up.hipnc

The sweep node has a rolling function. loop_shape.hipnc

Hi Guan, exactly, the polyextrude node can take all sorts of masks and measurements for individually orienting and scaling its extrusions. extrude_feather.hipnc

Hi Ahmed, there are specific volume noise nodes now which even support masks. erode_volume.hipnc

Hi Ronald, the sweep SOP surface can be set to rows. It accepts pscale, up and N attributes as well as cross section curves for the second input. sweep_rows.hipnc

I wrote an article explaining the code for the COPs raytracer a little: https://procegen.konstantinmagnus.de/custom-raytracer