I'm making a racing game and I'm having problems with Z-Order.
The track is formed by four models: one, the track itself; two, the high-speed turns; three and four, the guardrails. Their Z-Orders are for some reason wrong, so things are rendered in front or behind of them despite their spatial distribution.

Here are some examples:




Please, somebody help me!!

z sorting materials have been posted from time to time.

material zsort{
effect="
texture entSkin1;
technique zs{
pass p0{
texture[0]=<entSkin1>;
zenable=true;
zwriteenable=true;
alphablendenable=false;
}
}";
}

Don't get confused by the previous post - not even I understand it - but here's what you do for avoiding z sorting problems:

- Make sure that you are using the recent engine version. Old versions had a 16 bit z buffer.

- Fix level design faults, like blocks or meshes that are extremely thin or intersect each other.

- Adjust the view clip_near and decrease the clip_far parameter until the requirements of your level is met.

In internet game design forums you might find more advices about proper level design that does not produce z sorting problems.

Also, avoid textures with alpha channel or transparency as this often causes Z-sorting problems. However, with a simple material, this part can be worked around.

Is this the same problem? I'm using A6.40.5 Extra. I've got these treetops which are box-shaped MDL's, with a TGA skin of leaves. I also tried it with alpha-channeled DDS (dxt3 and 5) and the same thing happens.

The leaves are somehow being cut out, wherever the silhouette of the objects inthe background are. They do not intersect, and the background geometry is actually pretty far away. These aren't sprites, they're models with alpha channels.

Here you can see what the treetop cube should look like (the problem isn't too visible here):



Now here you can see the same treetop cube with the problem significantly more visible.



You can also see how the leaves are visible directly in front of the tree (it looks like they are painted on the tree), but obscured by the far-away MDL terrain geometry behind it.

This has me stumped (hah little tree joke there). Does anyone know how I could remedy this? I hope there's a way, because the "avoid textures with alpha channel" solution is a non-solution.

I'm using 6.40.5 Extra.
yours,

Your screenshots aren't showing for some reason (it could be my somewhat unstable internet connection).

Edit: never mind - I had to view the page sounce and click the "retry" button about 5 times just to view the screenshots saying it couldn't find the server....

Just wondering, have you tried making a wall as a model and putting a transparent object behind the wall to see if it renders? This is the simplest of test levels one could make....

Hi Ulillillia,

>Just wondering, have you tried making a wall as a model and putting a >transparent object behind the wall to see if it renders? This is the simplest >of test levels one could make....

Hm, I haven't tried that, but I'm pretty sure putting it behind a wall would correctly the whole object.

It's the silhouette of the stuff behind the alpha-channelized model that's cropping out the image.

is the object in the background transparent too?

transparent objects can't use the z-buffer (it's described in the faq forum).

Yes, that's what I'd also suspect.

If you have several transparent entities, the origin distance will determine which will be rendered first. Your image looks as if the origin of the blue object is closer to the camera.

See Manual -> entities -> transparency. There are several solutions to that problem.

Hi guys thanks for all your suggestions.

Let's see, here's the assessment:

1. The background object is not transparent-- it's a very large piece of MDL geometry. It's a 24 bit dds texture. I tried switching it to bmp but it didn't change this.

3. There aren't any other transparent objects behind this 'treetop' cube on which the texture is. All the other geometry has transparent = 0 and alpha = 100, and 24 bit textures only.

4. I tried changing the d3d_entsort to all three possible settings. It didn't change anything. This was per the manual's entity:transparent section. It mentions the same problem you describe re: intersecting transparent polygons, but in this case there is only this one polygon. But otherwise I didn't see any other solutions mentioned.

5. I tried using 32 bit DDS, and then 32 bit TGA on the 'treetop cube' to see if this would change things. No difference.

6. I tried adding a block skycube to see if that would help, but no difference.


Each image is of the same stuff, only from different angles. Here the order is from closest to furthest away: treetop, grassy hill thing, purple cube. The purple cube is quite far away.

I appreciate your insight on this!