Print Page - Transparent shaders (grates, trees and such)

Title: Transparent shaders (grates, trees and such)
Post by: Czestmyr on January 05, 2007, 12:19:24 PM

Hi, I tried to create my own tree branch texture with a transparent shader. Here's the code:

Code:

textures/trees/vetev
{
	qer_editorimage textures/trees/vetev.tga
	surfaceparm nomarks
	surfaceparm nonsolid
	cull enable
	{
		map textures/trees/vetev.tga
		depthWrite
		alphaFunc GE128
	}
	{
		map $lightmap
		blendfunc subtract
		tcGen lightmap
		depthFunc equal
	}
}

But there are a few issues:
* The shader has to be one-sided because if I disable culling, both sides share the same portion of the lightmap, which looks weird.
* The surfaceparm nonsolid and surfaceparm nomarks parameters don't seem to work
* I want the surface to occlude the sunlight and cast nice shadows, which it doesn't (view the attached picture)

Edit: The bushes in the attached picture consist of three crossing planes, which in turn consist of two 3x3 patch meshes, so that these planes are visible from both sides (as I said, using just one patch mesh and making the shader two-sided would look odd)

Title: Re: Transparent shaders (grates, trees and such)
Post by: dmn_clown on January 06, 2007, 06:47:49 AM

Those look good, at least with that lighting. The only bad thing is that it is insanely difficult to do realistic vegetation in a video game. I think the better route would be to do a playerclipped md3 model.

Even the commercial games can't seem to get vegetation to look right, an example would be Croteam's Serious Sam 2 which had awesome looking fields of wildflowers until you looked at it closely and realized that everything was an autosprite (in q3 shader terms).

Title: Re: Transparent shaders (grates, trees and such)
Post by: fromhell on January 06, 2007, 02:11:32 PM

In speaking of vegetation, JKMakowka's tree models for q3a are under the GNU GPL, i haven't bothered committing them to the project yet

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OpenArena Contributions => Graphics => Topic started by: Czestmyr on January 05, 2007, 12:19:24 PM