nmg_collapse — Simplifies an existing nmg_shape by a process of edge decimation.


nmg_collapse {old_nmg_shape new_nmg_shape maximum_error_dist} [minimum_angle]


Simplifies an existing nmg_shape by a process of edge decimation. Each edge in the old_nmg_shape is considered; if it can be deleted without creating an error greater than the specified maximum_error_dist, then that edge is deleted. If a minimum_angle is specified (degrees), then the edge will not be deleted if it would create a triangle with an angle less than minimum_angle. The resulting shape is saved in new_nmg_shape. The old_nmg_shape must have been triangulated previous to using the nmg_collapse command. The resulting shape consists of all triangular faces.


The example shows the use of the nmg_collapse command to simplify an existing nmg shape by decimating its edges. The new nmg shape will be within a maximum error distribution and will not have any triangles with angles less than a given minimum.

Example 1. Create a new nmg shape by decimating the edges of an existing nmg shape.

mged>nmg_collapse nmg_old nmg_new 1.0 10.0

Decimates edges in nmg_old to produce an NMG with an error no greater than 1.0 units. The process will not create any triangles with an angle less than 10°. The new NMG shape will be named nmg_new.




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