# Turn edges into separate primitives

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What's the fastest way to turn edges into separate primitives? E.g. given a simple quad (1 primitive, 4 points), I want to get 4 primitives, one for each edge, for a total of 4 primitives, 8 points. I can do this in a small loop, using Add SOPs, but I wonder if there's a faster solution with just one or two SOPs.

Edited by guache

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Depends if you want the un-shared edges or all edges, but the method is the same..

For un-shared edges add a Divid SOP and turn on Remove Shared Edges (turn off Convex), for all edges skip this step.

Add a Group SOP, set Operation to Group by Range

Add a Blast SOP for that group1

Add another Group SOP, set Operation to Group by Range

Add another Blast SOP for that group1

Add a Fuse SOP (turn off Degenerate)

Edited by hopbin9
• 1

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Carve SOP.

Fist U : 0

Second U : 1

Breakpoints : Cut At all Internal U Breakpoints

• 6

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Carve SOP.

Fist U : 0

Second U : 1

Breakpoints : Cut At all Internal U Breakpoints

Wouldn't that only work on NURB primitives?

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Nop. Works great on mesh also.

carveSample.hipnc

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Carve SOP

Cool, thanks. Exactly what I wanted.

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Cool, thanks. Exactly what I wanted.

Two more ways. Short and Long.

A. Use curvsect sop and plug the primitive in both the inputs. Leave it to defaults. Done.

B. Little not intuitive use of copy sop to remove geometry.

Append sort : carve: blast: copy sop to your polygon with following settings.

1. Sort- by vertex order(just to make sure if points are not ordered)

2. Carve- Make first U = 0( this should split point 0 and give you total 5 points)

3. Blast- Choose group type "Edges" and Delete non selected using expression in group field < p`stamp("../copy1","num",0)`-`stamp("../copy1","num",0)+1` >.

4. Copy - Rename copy sop to copy1 if not. Set number of copies to 4. ( you could also automate this and fetch points using pointlist and argc from the original polygon). Enable stamp inputs set the variable "num" to value \$CY.

Done.

-Cheers!!

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use wireframe

wire radius 0 switch of round corners.

then Convert

Connectivity Columns

U 0.001

then delete

by range

Done

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In Houdini 15 you could use the convert line SOP.

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On 10/10/2011 at 2:45 PM, ben said:

Carve SOP.

Fist U : 0

Second U : 1

Breakpoints : Cut At all Internal U Breakpoints

Would this be the same as the current "Unroll U" stuff?

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