How to create billboards for Oblivion SpeedTree tree

[Razorwing]

[What is this tutorial about?]

If you enjoy making your own trees with SpeedTreeCad but are annoyed at the CS spurting assertion errors when they're loaded, or stumped on to how to make them work with LOD, you might want to read this tutorial on how to solve those problems.

[What do I need for this tutorial?]

You need:
- SpeedTreeCad (http://www.speedtree.com)
- Paintshop Pro (http://www.jasc.com)
- DXTBmp (freeware; http://www.silgrad.com/wbb2/jgs_db.php?a...6&katid=11)
- Windows calculator

[Thankyou's]

Thankyou to PoHa! and KhadirgroGhurkag for sharing how the method works.

[Disclaimer]

I'm not saying this is necessary the best way to do it, but the method works none the less.

[title]1. Getting the tree image from SpeedTreeCad[/title]



The secret to getting custom SpeedTree trees to work with LOD, and avoid the annoying assertion errors at the same time, lies in creating billboard images. A real billboard, as you know, is a flat surface along the road used to display advertising. These kinds of billboards remind of the real ones in the sense that they are flat surfaces displayed to you; in essence, your trees are replaced with advanced sprites when viewed at long distances. (For you youngsters out there, a sprite is a two-dimensional picture us oldies had to contend with in computer games of yonder.)

So, the first step is to get the image we need from SpeedTree, and then we're going to work some on it.

Load up your *.spt tree in the program, then go to "File > Export > Tree image...".
Set the size to 1024.
When prompted, name it exactly like your *.spt model (but obviously not with the same file ending) and save it to a folder on your computer.

[title]2. Editing the billboard in Paintshop Pro[/title]



Open the *.tga you exported in Paintshop Pro. You'll notice it's dimensions are random, like in the example above 571x637. We want it to be 1024x1024 without having to resize it. So, fire up your everyday windows calculator. Calculate what 1024 minus your image's width split in half is (i.e. 1024-571/2). Go to "Image > Add borders..." and add those two numbers to the left and right. If you did it right your image should be 1024 pixels wide with the picture in the center of it. Now subtract your image's height from 1024 and add that as border at the top. Resize it to 512x512 (or 256x256 if you like) using Bicubic resample. After you've resized it, save it.

[title]3. Fixing it in DXTBmp[/title]



Open the *.tga file you edited in Paintshop Pro in DXTBmp. Go to "Alpha > Apply Alpha to Image". Do NOT try to create an Alpha channel, as that will destroy the perfect alpha channel that is already there from when you exported it from SpeedTreeCad. Save it to your folder as a DDS DXT3 texture, then move it over to your folder in "data\trees\billboards\". As you can see in image #13 and #14, you should have your *.spt files and your billboard files in a directory named the same.

Right, that should be it, you're done.

/Razorwing 2006-12-03