[b]Hello,
Ive had some great help here before, so here is my question:[/b]
I am looking to ONLY select the faces that are visible and part of the “exterior” of a model.
For example I have a CAD model of gas tubes and gear boxes…and what makes the poly count so HIGH is there is an inner mesh (normals pointing in the opposite direction) directly underlying the entire object.
I want to be able to select just that exterior–outer polys( and then invert the selection to delete the unneeded polys).
These underlying polys run throughout the entire mesh. It is not just those polys OPPOSITE the camera direction (because some polys would be facing the camera, say in a spherical example) but throughout the whole mesh…I am unsure of how to seperate the inner and outer meshes.
Let me know if this question is unclear. I’d appreciate any help!
Hello, would you mind using external application?
http://meshlabstuff.blogspot.com/2009/04/how-to-remove-internal-faces-with.html
Whoa!..this is pretty cool!
I definitely wouldn’t mind using another app…etc. (strange it didnt come up in any searches I did in Google?)
Is this your technique?
Are these built in tools within MeshLab?
Thanks for your suggestions!
Nope, it’s not mine technique, all the credit goes to the blog contributors I’ve just stumbled upon this post before.
As for your second question, yes, just download the latest MeshLab release and look for the menu items mentioned in the text; the only downside is that there’s no undo function in MeshLab so you’d better not get carried away trying all that stuff The technique works more or less as advertised (as far as I can tell, having used it to optimize some iges meshes where all the nuts and bolts inside were part of the model), sometimes it’s only necessary to revise the resulting mesh and adjust it to your likings if some unneeded parts are still there.
Hope it helps.
I would just like to second that MeshLab works well for a variety of things. Great tool indeed!
Seems like you could use the same technique described on the Meshlab blog inside of Max itself.
What they’re doing is rendering an ambient occlusion map, baking it to the vertex colors, and using that to find faces where all three verts are black.
Here’s a link to a tutorial video on baking the occlusion map to vertex colors:
http://area.autodesk.com/louis_tutorials/set_vertex_colors_from_ambient_occlusion_map
This thread could help you scripting such a thing…
http://forums.cgsociety.org/showthread.php?f=98&t=816933&highlight=ray+backface
48design, JHaywood
Thanks for your links! I would love to script such a tool.
I am going to look into it this weekend.
I have a general question of Ambient Occlusion being baked into the Vetex Map (colors?).
If I baked the A.O into the vertex colors…and then made a Cg shader, say blending the vertex colors (like in this thread: http://forum.mentalimages.com/showthread.php?t=1396 ) and say an environment shader…is the vertex colors read in as the baked A.O?
Thanks everyone…