Frequently I will draw a rectangular wall in sketchup only to have it dissolve into multiple angular planes. Is there a tool that will look at my geometry and remove all the messed up planes, merging them back into a straight wall?
Geometry doesn’t dissolve into multiple angular plans for no reason. Something you are doing must be causing it. It’s better to find out what the problem is and stop it happening than trying to clean up after.
Do you have a model where this has happened that you can attach?
There are various clean-up tools available to tidy up stray edges and close some faces, but the only way to guarantee clean geometry is to construct it correctly in the first place and take measures to protect it from damage.
This problem usually happens after I do Intersect with Selection between two groups that I want to merge. After closing the groups, I find new hidden geometry cluttering up groups that were not selected.
Please expand a bit on exactly what steps you follow to do this. What concerns me is that two Groups are separate contexts. You can’t select entities in both of them at the same time, so you have to be doing more than your brief description tells. Also, the results of intersect-with aren’t hidden, so something else is going on. Any chance you could share the model where this is happening?
There are a few different types depending on what you want to do… but one of the most handy is Thomthom’s CleanUp