BTB Rendering x Gmotor2 x 3DSimed

[Satangoss]

I'm trying understand some differences between BTB rendering method, 3DSimed and RFactor (or GTR2) engine itself.

Cannot figure out how some transparent textures edges are rendered on those methods. For instance (look at dirty grass next the wall)

3DSIMED:

BTB:

IN GAME RENDERING (Gmotor2):

It looks like DDS edges are more to BTB than 3DSimed method. 3DSImed shows texture nice, but in-game and in BTB it's blurry and crapped. I could't realize which texture's property would provide a better transparent texture, becoming it sharper. The in-game effect is too bad for visual purposes. Mip map bias doesnt appear to impact edges significantly.

Some clues are wellcome.

 

[Pablomartino]

I have the same question mate... thanks for answering it and hope somebody can give us a little light in this way.

 

[mianiak]

Not too sure if i understand your question. Are you talking about white lines around the edge of the transparent part of a texture?
Like this.

 

[Satangoss]

Mianiak, I ain't sure if the blurry transparences are related to those white edges. But the difference from ISI & Sinbim tracks for mine regarding of texture quality (mainly transparent ones) is huge.

 

[RT1971]

When you make any transparent trees or grass make sure the background colour is close to the colour of your trees or grass when using alpha.

 

[Satangoss]

Hmm, that's a nice clue! Thanks.

 

[krunch]

What you guys are seeing is edge pixels blending beyond the alpha channel's edges in chroma transparency materials. In ISI's 3D Studio MAX tools you can set the amount of edge pixel blend, however in BTB you can't change it - its hard coded. This issue cropped up a while back and Piddy fixed it in an update so that there was zero edge pixel blend. Unfortunately the issue seems to have crept back in since v8. I'm hoping Piddy will either release a patch or fix the problem in v9.

To work around the problem I've had to edit the alpha channels for all textures that use chroma transparency. I've made the alpha channel's edges contracted back about 3 pixels.