9 replies to this topic

[magneto]

One of the digital assets I am experimenting, I need a way to get the edge loops from a pair of points:



I thought I might be able to do this in VEX using the Neighbour VOP, and only include ones that are not already in the point selection/group, but I also need to be able to get the primitive neighbours.

If I achieve this in VEX, it will still have to run several times till there is no more room to grow. So not sure if it makes sense with VEX.

I looked at the Python HOM, but that also doesn't seem to have a function that could help.

Can this be done? Am I missing something?


Thanks

[mantragora]

No support for edges in Houdini. Still. In 2012. That's the best procedural program that doesn't support them. It's a feature you don't find in other packages. Every other can get them. But not Houdini.

Clear enough or should I continue ?

And I would not recommend walking on the edge. It's quite dangerous. You may get hurt.

PS.
You can try in HDK. I think you can get there edges.

[petz]

have a look at the pointneighbour and primneighbour expression. maybe you could adapt the file in the link below to do what you need. the principle is quite similar.
http://forums.odforc...dpost__p__91904

hth.
petz

[magneto]

I was hoping there would be some clever trick. But since the geo engine is new in H12, I assume edges are in their plans for H13 hopefully. Not a small feature, but definitely a key one I think.

Hopefully H13 will deliver us

EDIT: Thanks petz, your example looks interesting, will have to take a look at it more closely.

Edited by magneto, 21 June 2012 - 03:17 AM.

[rafaelfs]

magneto, on 21 June 2012 - 03:15 AM, said:

I was hoping there would be some clever trick. But since the geo engine is new in H12, I assume edges are in their plans for H13 hopefully. Not a small feature, but definitely a key one I think.

Hopefully H13 will deliver us

EDIT: Thanks petz, your example looks interesting, will have to take a look at it more closely.

You might be able to traverse the edges using UV coordinates... Just a thought, but in the case of the grid, you would be able to find the UV "latitude" or "longitude" of a point and then just loop through all the connected points that have the same respective coordinate.

Haven't tried, but sounds feasible in some cases at least...

Aslo, the shelf edge loop tool seems able to find a the loops, maybe you could reverse engineer it...

Cheers

Edited by rafaelfs, 21 June 2012 - 06:57 AM.

[mantragora]

rafaelfs, on 21 June 2012 - 06:56 AM, said:

Aslo, the shelf edge loop tool seems able to find a the loops, maybe you could reverse engineer it...

It just calls polysplitSOP. So we are back in HDK/InlineCPP land, if we want to replicate it.

[magneto]

Thanks rafaelfs, I need this to work for any geometry so UVs like you said might not solve it 100%.

I didn't know about polysplitSOP backend. I will check it out.

Does it use inline cpp?

Edited by magneto, 21 June 2012 - 06:25 PM.

[magneto]

I just actually just looking at the edgeloop code, and it uses customStateTool which returns genericTool. But not sure where 'edgeloop' argument calls the actual tool?

Is there another location for these or are these just compiled thus can't be inspected?

Thanks.

[petz]

attached is the modified file that should do what you need. depending on the number of polygons you may want to go the hdk-route.

hth.
petz

Attached Files

•  edges1.hipnc   93.9K   62 downloads

[magneto]

Thanks petz, that's a new interesting trick