Page Comparison

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Allows you to choose the interpolation of the UV coordinates for the new geometry, choosing from (taken from Pixar's specification): 

• None: doesn't perform UV interpolation  No boundary interpolation behavior occurs 
• Edges: interpolates the UV coordinates from the UV coordinates of the nearest edges  All the boundary edge-chains are sharp creases; boundary vertices are not affected 
• Edges and Corners:  interpolates the UV coordinates taking the UV coordinates of both the nearest edges and All the boundary edge-chains are sharp creases and boundary vertices with exactly two incident edges are sharp corners 
• Sharp: Smooths only near vertices that are not at a discontinuous boundary. All vertices on a discontinuous boundary are subdivided with a sharp rule (interpolated through). 
  
  

Edge Crease 

When set to 0, the polygon is divided evenly at the middle of its length. A higher value approximates the new edge to the original edge, concentrating the subdivision near the edge. This setting is useful to bevel the edges of the model. 

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Angle between two polygons below which the normals are not smoothed after the subdivision, maintaining their original orientation.