when I place a lot of the same objects, they seem to despawn after a while and this is proving to be a problem when making a forest any ideas
By "despawning", do you mean disappearing after pasting lots of Speed Trees?
If this is the case, it's a Speed Tree issue, which requires that you save your route exit to the menu and the go back and edit. This will work for a time and the you'll have to exit from Trainz TS12 and then go back in again. From the technical side, it's caused by a memory leak in their software plug-in, which means when a function is called and the data placed on the temporary stack, the memory location isn't released once the data function has been used. Multiply this by a gazillion Speed Trees pasted down a gazillion times, and you'll run out of memory quickly.
With other assets, such as some train cars, and scenery objects, this is due to older assets not processing properly. This can cause whole areas to disappear in earlier versions of Trainz such as TS2010, and pre-SP1. SP1, however, brought on another issue, which caused assets not to load quick and enough and N3V did, however, make some changes for this in SP1 HF4 which has helped tremendously, but it's not perfect.
John
