SubdivideOp

Apply subdivision to increase the resolution of the input surface.

Currently, only Catmull-Clark subdivision is supported.

Inputs

The Input Surface is subdivided.

Parameters

If a Partition Attr is specified, the original primitive number will written to a primitive attribute as a string.

If a Subdiv UV Attr is specified, the a sub-UV vector is written to the output points representing the coordinates within the original primitive.

The Depth specifies how many iterations of subdivision are applied.

A non-zero Flat Depth will cause some number of the iterations to be applied with linear interpolation, up to the total number of iterations. The flattened iterations will be the finer steps near the end of the process. Flat subdivision results the same topological face structure, but without the smoothing and shrinking associated with subdivision. This may be useful for blending or comparative metrics.

Unless Recompute Normals is selected, the existing normals will be interpolated into the results.

Specifying Wrap UVs will adjust any values below zero or above one. Only the fractional part is retained. This presumes that unit UVs are used.

With Bridge UVs, face vertices with wide differences in UVs values will be evaluated to guess whether they are actually crossing a wrap boundary. This is an imprecise test and can cause artifacts if the guesses are poor. The Low Margin and High Margin are thresholds for where a cross over is considered.

If Expand is on, the output is bloated to counteract the inherent shrinkage due to approximating subdivision. The effect is moderated with by Expansion.

Using Write Hull Indices will print all the input point index values that each output point used into a string point Hull Attr.

Status

TESTING
tested in Houdini