Broken Surfaces? Very Strange Triangulation

Since you were so helpful on my last post I have one more for you.

I’ve ran into this issue with rhino several times over the last week working where my surfaces start out fine and at some point the entire file (including new surfaces made) become computed through some strange triangulation of the surface. From a distance they look normal but as you zoom in they reveal some strange conditions. I have attached a screenshot to show you what I am talking about. I have actually found that when exported to an .stl to be 3D printed it actually begins to show up in the 3D prints indicating that it is not just a graphics error but the model is being calculated differently than normal surfaces.

Hi Philip - this looks like the meshing you get when objects are very far from the World origin - is that the case?


I do not believe so… I will reopen the file again and see however when I was having this issue I did do several attempts of exporting the geometry and importing it into a brand new file with a unit scale appropriate for the size and detail of the model. The reason I am especially confused with this one is the glitch in the geometry was actually appearing when I would export into makerbot software for a 3d print and run the print you could see the imperfections from this triangulation. This leads me to believe that it’s more than a graphics issue but there is something I was doing in the modeling process that at some point corrupted the way rhino processed any surface in the fine. When I exported into new files the same issue re occurred. I had to rebuild the entire model to work around the issue in this case but I would love to hear in the future that there is some type of easy fix…

Although Rhino is far superior to sketchup I am aware of a similar issue that happens in sketchup that corrupts the processing of surfaces in your sketchup file (typically if your file gets too large or complex) and the result is very similar.

(when importing it to a new file I always brought it to the origin)

Hi Philip - can you export a couple of the ugly objects and post or send to me via private message? I’ll take a look.



if this is the same file as your other problem extremely strange zooming then @pascal is right and your objects are “very far from the World origin”

_SelAll _BoundingBox _CoordinateSystem=World _Enter
check the dimension-Result written in the command Line History (F2-Key)

or try:
Save your file with new Name, use option "save Small"
close and reopen the “small” file. All Rendermeshes will be recalculated.