Hi,
Im looking for a simple Shadow Shader, that uses the
Z-Buffer technique.

Such as:
http://en.wikipedia.org/wiki/Shadow_mapping

The shadows dont need to have a good resolution.
They mainly need to be fast.

Just like this example:

There is a shadow mapping example in the GStudio folder (samples/shadowmapping.c).

Ok, i will try that one.

If you don't mind getting a little more complicated, there's a CSM tutorial on my website here. More specifically, it's how to adapt the shadowmapping.c code Superku pointed you to into Cascaded Shadow Mapping, which is relatively easy but effective over huge distances.

Jibb

Cool, I will play around with the standard example, and
then look into your advancements.

The shadow rendering looks nice.
But is there a way to keep other material and lightsettings?
They are overwritten by the shadow material.
And the "bottom" (non lightened) parts of the
models are totally black.

Can the shadows be added / mixed to the scene with
the standard material/lightning?

I believe my tutorial also makes the shadows mix more nicely with the standard lighting.

Jibb

ok, I put in
return tex2D(TexSampler,inTex) * fShadow * max(0.15,fDiffuse);

to keep the bootoms from getting totally black.
(works for now)


Jibb, you example is cool for explanation.
Its just a bit slow with the 3 views.
Is it possible to only use the "widerange" view, but
then add other materials and lightemittions onto the map?

It is possible to use fewer views. There is also room to make it faster, with functions that have been added since then in A8 (such as view_check). If you want to use just the widest view, it's mostly be just the same as the original shadowmapping.c example with a couple of changes.

If I were you, I'd use:
This will make a smooth transition from the cast shadow to the diffuse lighting. Then, if you need the shadow to be less dark, change fDark near the beginning of the .fx file.

The way it is set up, you'll need to add the shadow stuff into each different material manually if you want them to receive shadows.

Out of curiosity, what are your system specs? And what kind of framerate are you getting?

Jibb

its about 25 FPS on 1024x768 on your examplelevel.

on the original demo its about 130 FPS on 1024x768.
(I added a few models too, so its not the models themself)

I dont have a very new Computer, but (beeing conservative) I dont want to
see an FPS drop that early on.