better grass

Virion · Post by **Virion** » Sun Oct 04, 2009 3:33 pm

this is my current grass model

but i'm not quite satisfied with it. anyone know any better grass example that i can refer to? (preferable wireframe) thanks in advance

BlindSide · Post by **BlindSide** » Sun Oct 04, 2009 7:11 pm

I think it looks great except for the X shaped part pointing towards the camera. Maybe you can animate it too?

Virion · Post by **Virion** » Sun Oct 04, 2009 7:52 pm

BlindSide wrote:I think it looks great except for the X shaped part pointing towards the camera.

hmm... the problem is all the sides have this X shapes

BlindSide wrote:Maybe you can animate it too?

yea i will. otherwise the level will be too static and boring

andrei25ni · Post by **andrei25ni** » Sun Oct 04, 2009 10:52 pm

is your grass going to be tiled?

I'm studying the grass in Battlefield 2, and trying to add something similar to my game.
They apparently used fixed billboards, positioned at random rotations, and they match the color of the texture of the terrain. And in return, the texture of the terrain also mimics the grass billboards, like it's flatten.

Here are some Battlefield examples:

http://evilworksgames.deathtouchstudios ... een030.jpg
http://evilworksgames.deathtouchstudios ... een031.jpg
http://evilworksgames.deathtouchstudios ... een078.jpg

And here are some of my attempts:

http://evilworksgames.deathtouchstudios ... pic_42.jpg
http://evilworksgames.deathtouchstudios ... pic_43.jpg
http://evilworksgames.deathtouchstudios ... pic_44.jpg

DavidJE13 · Post by **DavidJE13** » Mon Oct 05, 2009 2:04 am

andrei25ni; that looks good (battlefield and yours). I suppose the key here is making the ground texture match the tuft texture quite closely. How are you positioning & rendering the nodes?
I would suggest an improvement to the method; add a simple shader to make the tufts fade to invisible as the angle they make with the camera gets smaller. That way the odd-looking side-on quads won't be visible. Not sure how much this would effect performance. Also making the quads smaller (vertically) towards the edges of the grassy area would make them look more realistic IMO.

btw, you'd be much better off using ALPHA_CHANNEL_REF instead of ALPHA_CHANNEL; it'll remove the odd glowing around tree leaves and significantly increase FPS with that many grass nodes.

Dorth · Post by **Dorth** » Mon Oct 05, 2009 4:22 am

I often see grass patch attempt as a quad put vertical on the ground, 2 corners up. However, the best patch I saw was a triangle/quads with one corner up.

arras · Post by **arras** » Mon Oct 05, 2009 9:33 am

Virion >> I would say problem is in density of your grass pattern. If you would draw individual blades at bigger distance from each other, they would not blend together under small angles to camera making faces of your model so noticeable.

Bye the way the same problem often occur with modelling trees and its hard to overcome if you want to keep your polycount reasonable.

Eigen · Post by **Eigen** » Mon Oct 05, 2009 9:45 am

I'm using grass blades that are modeled like this. 3 triangles total.

Virion · Post by **Virion** » Mon Oct 05, 2009 9:47 am

thanks for all the tips. i've made it slightly better now. no more X shape.