If you do that, the folder for the part will be replaced with folder containing a single tga file, meaning the existing part folder's contents will be completely overwritten, therefore the part is deleted. The other option - individually replacing parts for 61 folders? No thanks. Edit: Actually, it depends what version of OSX you are on. I've been on ML for a little while now and didn't realise the process has changed from SL and Lion. If you hold the option key when you drop the folders, there will be an button called "Merge" (on ML) with an 'Apply to all' tickbox.
If you do that, the folder for the part will be replaced with folder containing a single tga file, meaning the existing part folder's contents will be completely overwritten, therefore the part is deleted. The other option - individually replacing parts for 61 folders? No thanks. Edit: Actually, it depends what version of OSX you are on. I've been on ML for a little while now and didn't realise the process has changed from SL and Lion. If you hold the option key when you drop the folders, there will be an button called "Merge" (on ML) with an 'Apply to all' tickbox.