In 3D Viewer I am only seeing the copper on the outer layers of an 8 layer board. I have ‘show board body’ turned off so I can see inside the board, but there is nothing there except the vias. How do I control which copper layers are visible in 3D Viewer? KiCad version 4.0.7.
You need to deactivate the “Realistic mode” on Preferences of 3D Viewer.
Looking at the 3d view in this way isn’t really a good alternative to reviewing the Gerbers. As well as numerous 2d viewers, there are some 3d gerber viewers available which you might find helpful if you like to see a multilayer representation of your board - especially if you want to check continuity of specific traces with a ‘fly through’ mode.
Screenshot from zofzpcb