A few questions
 

I can't figure out how to do proper transparency for my trees. http://www.miriscusltd.com/snowyplain_snowy.jpg ingame, they're black where it should be transparent, though in openzone http://www.miriscusltd.com/snowyplain_wip5.jpg they look fine.

Any idea why, and how it can be fixed?

Also, how do I make a cave? I created my terrain in openzone, and exporting it doesn't work very well. Is there any way to make a cave in openzone or am I just screwed?

And lastly, when I test my zone out in EQ, there are some weird lighting issues.
http://www.miriscusltd.com/snowyplain_wip.jpg This is the best pic I have of it, even though it is an outdated picture.

Any help? Sorry to doublepost+bump. It's normally against my ways ;)

sounds like you haven't checked the "masked" checkbox in the properties of the sheet you used in your tree. OZ just looks at the texture and shows it as transparent in the alpha channel, it has to be marked as masked for the client to do it.

Yes, you can. Make the object that will be the inside of the cave (I like DungeonBuilder for anything really big but you can use any modeling program) export it to 3ds. In the ground texture editor, I think you "right click" the area you want to remove the ground from. Once you do that, import your 3ds model and put it in the opening in the ground cover - probably in the side of a mountain.

it looks like the round building is floating above ground, but I'm not sure what you mean by lighting issues.

You can also use Mesh...Split with ground mesh after you import your cave/dungeon. It will split:

- dungeon polygons that intersect the ground
- ground polygons that intersect the dungeon

Then you could:

- remove extra polygons around the dungeon entrance
- go into the ground editor like Scorpious2k said and right-click certain ground tiles to hide them (sometimes necessary, but not always)

The basic idea is that the dungeon most likely pokes through the ground and you want to create a seamless boundary where they meet. Split with ground mesh does this, and then you just remove the leftover polygons and (maybe) hide certain ground tiles. Where part of a ground tile should be removed and part should remain, the split option will automatically hide the ground tile and split it into the necessary parts--then you just have to remove the excess. If the entrance is so big that it entirely encompasses a ground tile then you'll have to hide that tile manually by right-clicking it in the ground editor.