I want to do a 3D print and CNC relief of some topography. When I import the STL of the terrain there are so many faces due to its high resolution and depiction of the natural topography that it really slows down my machine and causes it to crash. Smoothing edges and faces doesnt work, and neither does importing the file with merge coplanar faces box checked.
Any ideas here, I can always upgrade my machine as a last resort 
Unless you can open and work with the .stl in some other application and simplify it, I expect upgrading your hardware or exercising patience is the only fix.
what other application would you recommend for that?
I have not tried, but I understand that the Universal Importer extension incorporates a polygon reducer.
Outside SketchUp, Rhinoceros has a fairly competent polygon reducing command, and it has a 90-day free trial.
Thanks - I guess I could try Rhino - never used it before but I’ll give it ago
Why do you want to import the STL in Sketchup? You can use a .stl file directly in slicer software.
I need to project an image onto the STL so that’s why I was going to do it in sketch up
Get a free trial for Skimp.
Very fast stl import and polygon reduction. You can reduce the polygons before importing
I will vouch for Skimp. It has an amazing import that allows you to simplify files without losing the important details.
Cool thank you I will give that a try today and see how it goes!
Used Skimp - it seems to have done the job. I am wondering if when I go to program the CNC router with the slicer if the loss of resulation will be noticable with this topographic model. Any thoughts?
It would be nice if I could reduce the geometry/polygons for editing and then increase them again before I export for production. Any thoughts on that?
I can’t upload the sketchup file here for you to inspect because it is too large.
Look at it in the slicer. You ought to be able to get a pretty good idea.
You could use some various tools to increase the detaiil but it’s unlikely that you would get the same detail or accuracy. If you need the resolution of the original .stl file, you should just use it and not try to simplify it. Deal with the lagging using patience.
You could use Artisan to add more polygons and smooth the result.
If you are using triangulated geometry, use the subdivide command, then the smooth command for best results