Ultra-efficient tree texturing and modeling

Zyth

Hi, all. I'm running through Andy Zibits' Ultra-efficient tree teturing and modeling tutorial.
http://www.andyzibits.com/tut_maya_low_poly.html

I want to do everything except the Paint Effects section (obviously) in 3ds Max. I've created six clusters of leaves, however, I've run into a snag where it states, "
Do top-view TGA Production-quality renderings of these clusters at very high resolution (so that each leaf cluster gets around 1500-2000px sq. devoted to it."

First, should I do a top-view rendering of each of the six clusters individually or together?

Second, what type of rendering should I use: A normal top-view F9 rendering or render to texture? I've been having issues with both. Using a normal F9 orthographic top-view render the leaf alphas render correctly (opacity) however, its an aggravating task setting the area to be rendered with Edit Region. On the oter hand, when using render to texture to project the leaves onto a plane, its easy to setup however it seems to ignore the alpha on the leaves which obviously is undesirable. Is there a way to use alpha while rendering to texture?

Render to texture result:

Electro

Create a targeted camera and change its property to be orthographic.

This way it'll always render from the same spot, will be orthographic (so your planes near the edges don't skew with perspective) and will use whatever alpha settings you already have in your material(s).

Layout and arrange your clusters exactly how you want them to be in your scene to produce the texture you want. This reduces the amount of rework later on when you want to make a change to a particular cluster, so you don't have to then worry about moving it around etc in photoshop.

In short, fix everything so that it renders how you want.

Eric Chadwick

Also, set your background color to green (or similar to the leaf color). This will prevent leaks from giving you halos around your leaves.

Eric Chadwick

I should mention that Andy's tutorial does not represent a game-friendly method of making trees. It is usually very expensive to use a bunch of camera-oriented billboards. Most game engines are not optimized for this. Speedtree is specifically setup to render this efficiently, but you have to integrate their renderer into yours, and there's a license fee. The method also has visual problems.

Electro

Agreed, and the other reason to have the background match the main colour of your leaf is for mipmaps. As you get further away the background colour will bleed onto the texture, so you want to make sure it's a closest match to the original colour as possible.

Zyth

Really appreciate the help.


Do you know of any techniques or tutorials that represent a game-friendly method of making trees? I assume, like you’ve stated, that some tree generators will do the job. Do you know of any besides Speedtree that are optimized for games?


I also have a special case question involving “hero” trees. After modeling the trunk and some larger branches I’d want to add 2D leaves and smaller branches to fill out the crown. What is the best method for creating these assets and modeling the cards so that its optimized for a game engine?


Thanks again!

Eric Chadwick

Some more tutorials here, and some tools.
http://wiki.polycount.com/CategoryEnvironmentFoliage

Recently a co-worker made an in-house tutorial for how she generates tree card textures from high-res 3d models. Really the best way to go, since you can get very high-quality and natural-looking results, and you can generate a quality normal map as well. Can't share, but that's the jist anyhow.

Calabi

Just found this one earlier.

http://www.unifycommunity.com/wiki/index.php?title=TreeCreator_Tutorial

Eric Chadwick

Nice find!