get mesh topology lines.Ho Convert Line SOP > Facet Unique P

I want to get mesh topology lines and their two point postions.

I can do a functional mock of what I want using
-wireframe on geo, radius 0
-python for each prim get max and min
-add points of those max and min postions and add polygon by group

There must be a very simple way, like if the wireframe op offered lines instead of tubes as prims. Like Houdinis Convert Line SOP → Facet Sop with Unique Points on.
The nearest thing I could find in TD, Convert SOP only allows convert form Tube to particles at render.

I searched a lot before posting, so the answer has to be obvious :slight_smile:
Thank you, Graham

I would suggest converting the tubes to poly/meshes, but there seems to be a bug when the tubes are zero radius.
We’re currently looking into fixing that.

I assume you don’t have access to the wireframe with non-zero radius?

Rob thank you for answering.
I do have access to the wireframe with non-zero radius. Is there a solution to getting the lines of topology in TD without wireframe? I was just using wireframe SOP as I saw no other way to get the lines.
I can get the topology lines using the steps in attached toe and image.
But adding a heavy wireframe then deleting every 9 of 10 points to get back to 2 points for each place where there was a tube prim, then adding polys as lines, is really inefficient.
mesh2linePrim.1.toe (5.34 KB)

Try converting the mesh to points/particles with convertSOP and then use addSOP on them. Maybe you have to convert SOPtoDAT before you can use addSOP. (If so you can skip the convertSOP)
Not sure if that’s what you are after but the result should look similar. Then the new line material might be useful when rendering. Not on a computer so I can’t TD right now…
Best
Stefan

Also consider the Group SOP, select points by Edge, and turn on ‘Unshared Edges’.
This will at least give you all points used in unique edges.

Is that what you’re trying to compute, list of all unique edges?

It’s ok I’ll go with the really inefficient method I put in the .toe above. (although the math is slightly off as radius of zero doesn’t work, which might be an issue when I plot these out later).
I really really appreciate your help. I tried your last 2 suggestions but didn’t quite give me what I need.

I realize I was a terrible explainer in my first message. I’m trying to get the xyz co-ordinate pairs of each end of each topology line.
And just get the topology lines as prims. Exactly what your wireframe SOP does but instead of tubes, have lines. See attached image
Inkedunique_edges_LI.jpg

Hi Rob, the bug when the tubes are zero radius in wireframe SOP still seems to be there. Any updates on if it might be fixed?

Note not using facet unique points in latest example below as it offset the point numbers, but for loops doesnt.

It would provide the same functionality as the ‘convert line’ SOP in Houdini, which followed by a for each prim loop (with nothing it in it), would return the same looking geometry mesh but made of unique prim lines.
The small amount the co-ordinates are off has some issues that pop up using my silly method mentioned earlier in thread.
I tried using a script SOP but don’t see a way to read and list edges or connected points.

(don’t need it but fastwire stiil crashes)