A little help with low poly, good looking trees?

odium

I've started working on foliage, bushes, trees and the like for our new engine OverDose, based on our previous Quake II Evolved engine which is fully Per Pixel lit with MD5 models, animations and Doom 3 style material systems as well as a whole host of other things.

Anyway, I'm trying to do trees for our large (READ: Huge, they take up the entire grid in GTK at max size) maps, but I'm failing REALLY badly at every turn. I can do grass, bushes, flowers, all srots except the damn trees...

Now these trees wont be casting shadows, as the sahdows will be added in later to save on performance, so any tricks can be applied. What I'm rally after is some tips on making good looking but low poly trees. Alpha maps, sprites etc can be used so any tips are welcome.

Thanks guys.

Anyway, a few shots of my poor stuff so far:

http://www.quake2evolved.com/odium/overdose_1.jpg

http://www.quake2evolved.com/odium/overdose_2.jpg

http://www.quake2evolved.com/odium/overdose_3.jpg

All artwork, models, textures etc are mine except for the sky, which ATM is using hipshots wicked textures because they rock for testing

Eric Chadwick

Well it's a decent start, I think you have a good base that you can tweak without much hassle.

What do your leaf flats look like? I'm seeing totally flat color on the undersides, and the top sides look pretty washed out too.

Instead you might want to go with totally-emissive leaf planes, and on the undersides use a different darker texture (or better yet another part of the same texture atlas).

Might use a texture that's not so dark... the more contrast between your ground/sky and your leaves, the more aliasing you'll see from the alpha test. When they're in a similar value range, it'll be less apparent.

Also seems you're using just horizontal leaves... you'll want to vary the angles of those planes so you don't get the slivers when viewing from the sides. Also might try intersecting planes on each branch, for more fullness.

If you want to go with the SpeedTree-sprite technique, you'll need a vertex shader that will run a whole tree (or all the trees of the same breed) as a single entity in the vertex cache. Otherwsie the speed hit of all those sprites is going to cost too much.

odium

Any ideas on games that have some nice trees i can check and see how they did?

Eric Chadwick

Stalker, but that's vaporware.

StarWars RebelStrike had a great redwood forest.

Dead or Alive 3 also had a nice forest level too.

JKMakowka

http://arbaro.sourceforge.net/

I am still playing around with a decent technique to bake these highpoly trees onto some 'alpha planed' trees. So far it is turing out to be quite labor intensive thus I chickened out
But maybe I'll give it another try sometimes, or if you come up with a good and quick technique I would be grateful if you would share it.

Eric Chadwick

Thegodzero had a good technique here.
http://boards.polycount.net/showflat.php?Cat=0&Number=109451&an=0&page=0#109451

IMHO, using a L-system treemaker is painful, since it wants to create volumes, but for a game tree I just want to bake a single branch, with the leaves in pretty much the same plane (albeit rotated for normal-variety like he said). Then I use that same branch again and again to make my game tree, maybe adding a couple other branch types (dead, sparse, full). My 2 cents of course.