Howard Trickey
fbffff26e4
Two problems were fixed. One, the code for dissolving vertices left a face around if dissolving a vertex would leave less than three vertices. Instead, the face should be deleted. Two, with transformations like "rotate 180 degrees", this should be no problem with exact, but the current transformation matrix has very small non-zero entries where it shouldn't. Cleaning the transformation matrix makes it more likely that user expectations about coplanar faces will be fulfilled.