# Poly Split

The Ultimate Houdini node reference

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### Poly Split

Poly Split allows you to add custom cuts and edge loops to your topology.
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Summary:

There are many ways to engage this node, but the best way is interactively through the viewport.  Travel through the radial menus by holding down "c" and navigating to the polysplit option.  This node can be used to add cuts and edge loops to your geometry.

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General Parameters:

Split Locations:

-- This parameter is responsible for identifying where the cuts will occur. When you make cuts in the viewport, this will automatically be updated with the necessary expressions. If you’d like to know what these expressions mean, then view this info from the user documentation:

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avb
Cut at vertex b of primitive a, where a and b are integers.
aeb
Cut at the midpoint of edge b of primitive a, where a and b are integers.
aeb:t
Cut at t percent along edge b of primitive a, where a and b are integers and t is a real number from 0.0 to 1.0.
af:u,v
Cut at the given (u,v) location on primitive a, where a is an integer and u and v are real numbers from 0.0 to 1.0.
pa-b
Cut at the midpoint of the edge between points a and b, where a and b are integers.
pa-b:t
Cut at t percent along the edge between points a and b, where a and b are integers and t is a real number from 0.0 to 1.0.
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Path Type:

-- Shortest Distance = make a cut that’s not a loop
-- Edge Loop = makes an edge loop

Close Path:

-- This will attempt to close the split polygons into a closed shape. In most situations, you’ll probably want to leave this off, however, if you want to close the shape for any reason, then this is where you would do so.

Allow Split Points on Faces:

-- This allows you to add new points in the middle of faces. It may be useful to turn this off to prevent accidentally adding points to the middle of a face instead of an edge.

-- This will attempt to turn all of your cuts into new quad topology.

Number of Loops:

-- This adds more edge loops

Match Profile:

-- Instead of distributing edge loops evenly, you have the option of distributing those loops towards one side of the looped area. By turning this on, you enable this functionality. If this is turned on, then it will only make loops on 50 percent of the original looped area. If you turn this on along with “Edge Percentage” then it will create loops along an area that’s not 50 percent of the looped region. And finally, if that is all super-confusing, just watch the video where you can see it in action.

Switch Profile:

-- This will inverse which area of the distributed loops will occur.

Edge Percentage:

-- Please refer to the “Match Profile” parameters

Update Point Normals:

-- This will calculate the normals for the new loops

Edge Group:

-- This will output an edge group containing the new loops

Append to Group:

-- This will add these loops to an existing edge group

Tolerance:

-- According to the docs, “If you are working at very small scales, or if this node generates bad geometry where the split path is very close to corners, you can try decreasing the tolerance.”

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