Is there a way to reduce topography tin to more coarse grid?

I have a very detailed tin of an existing topography, very fine grid. I don’t need it to be so detailed and would like to reduce it to more coarse grid to reduce file size. Is this possible in SU?

Likely with an extension.

The SketchUp Team has an extension:
Simplify Contours Tool

Also, the Sandbox Tools extension comes installed with SketchUp. says:

The Sandbox Tools extension implements the concept of a sandbox which refers to a surface that can be generated and manipulated using sandbox tools. A sandbox in SketchUp (and in other 3D modeling tools) is commonly referred to as a triangulated irregular network or TIN in terrain Modeling terminology.

Switch on it’s toolbar via, menu: View > Toolbars… dialog. Dock it where you will. Open the Instructor window to see tool help.

Refer to the online User Guide chapter: Modeling Terrain and Other Rounded Shapes

Search Extension Warehouse for other extensions, “mesh” or “terrain” etc.

etc, …

I would try to reduce the topography in an external program (Meshlab e.g.) before the SketchUp import…