[Sandbox Tools] Problems using sandbox with contour lines


Hello All!

Hoping someone might be able to help me out. Have used basic sketchup as a high school design teacher for past year. Am now back in full time freelance landscape design and downloaded sketchup pro.

I want to create smooth contours from contour lines which I have imported as a DWG file from a survey. Having followed all instructions etc, I am still asked to select contour lines (even though they are selected) before it will render. Can anybody think what this could be?

The contour lines are one layer of the import and I am trying to sandbox/render with just this layer visible. Could this be the problem?

Help please…


It’s hard to tell without the model or an image but,

It sounds like your contours are inside a group. If the are you need to either explode the group or open the group for editing before sandbox will work.



That has worked, but has rendered all layers including buildings etc…

This is probly really basic, but how do I separate this layer?

Your help appreciated


In SketchUp layers do not separate geometry. Groups or Components separate geometry.

Layers are only for controlling display. (And are really mis-named, but someone thought the name would make ppl coming from CAD apps feel better, I suppose.)

Hidden geometry can still interact with new geometry. What layer things are assigned to does not affect interaction or not.


Ok, thanks, becoming clearer…

So how would I separate this group of contour lines from the rest of the survey? I’m sure I’m missing something very simple…

Any ideas?


Done it!, theres probably a more simple way.

I exploded all layers then switched the others off. Then sandbox/render just used visible…

Hope this may help someone,

Thanks for your time guys…