I have a n imported google earth screen shot as my base layer, i trace around the existing building as my next layer to get a plot layout.
Why when i am on layer #2 can i still mistakenly grab an move my base layer? I need it visible as i am not complete with my tracing of buildings on layer two.
Sometimes in the small adjustments i move the entire base layer, I have to back up a step to rest it to the original position and then start again.
What am i doing wrong?
So it’s actually the group that’s moving? Is it actually moving or are you shifting between the flat version and the terrain version? Are the groups locked? Do they highlight in red?
Are you really changing which layer is active? If so, you shouldn’t be. Layer 0 should always be left as the active layer.
Post the SKP so we can see exactly what is going on.
Your wording sounds like you have a common misunderstanding of SketchUp’s layers: SketchUp layers are referenced by entities to determine visibility. They do not otherwise “own” or “organize” the entities.
So, there is no such thing as “moving a layer”. You can move the entities that refer to a layer, but this has nothing to do with the layer itself. If you set a layer to be “active” (which as @DaveR has noted is generally not a good idea except for Layer0) all that does is cause new entities to refer to that layer for their visibility. It has no effect on access to any entities or your ability to move or edit them.
As DaveR suggests, you may not have thought to Lock the terrain group (R-click menu > Lock with the terrain group highlighted). Then if you click it or drag it by mistake, it will highlight in red to indicate it is locked, and won’t move.