Hydrax and PSVSM Depth Shadow Mapping


25-02-2010 20:13:36

Hey, I have been trying to make pssm depth shadow mapping work with Hydrax. And I am getting some issues.

First I get these random black areas that drift around under the water as I move the camera.

Second, I have 3 split points and only the first shadow map appears and the rest get cut off.

And 3rd, when I move the camera just above or under the water, all off these problems vanish.

I have tried this without vsm and with only pssm I have tied it with just standard depth shadow mapping and I get the same thing.

Hopefully someone else has had this problem. If not, any ideas?


27-02-2010 19:50:54

For me it seems to be something related with the terrain shadow receiver shader.
If you disable Hydrax, do you get the same issue?



28-02-2010 20:42:06

If I disable Hydrax there is no problem. So the problem must be with hydrax.

I also looked very closely at the hydrax SkyX demo, and the shadowing in that demo has the same drifting black line problem.(but not very noticable)

But I have figured something out. The only shadows that are not show correctly, are the shadows in the RTT reflection and refraction. So I changed one line in the hydrax source code from "shadowsenabled" to "false".(RTTManager.cpp) And now the drifting black line problem is fixed!

But, the RTT reflection and refraction still only displays one split point.

Thankyou for your reply .



24-08-2010 14:55:56

hi legends,
am having a project (maritime simulator).. And am in halfaway to do it.. hydrax and skyX are working but i really needs yr help in shadows..

regards, hamed


25-08-2010 16:34:59

I has got the same problem, but finally i could solve it.

The first thing that i think causes problem is you are testing z with a division. You must use substract (probably for this reason you have random shadows, and other shadows disappear).

If you want, you could download my game (in developing), where the shaders have been repaired. The name of the project is SonSilentSea, and you could download it here (Two first link are needed):

https://launchpad.net/~sonsilentsea-tea ... tu1.tar.gz
https://launchpad.net/~sonsilentsea-tea ... tu1.tar.gz
https://launchpad.net/~sonsilentsea-tea ... tu1.tar.gz
https://launchpad.net/~sonsilentsea-tea ... tu1.tar.gz

Jose Luis Cercós Pita


12-03-2011 01:47:46

Sorry for topic necrophelia but I am having the same issue with PSSM DSM and I don't understand what you mean by testing z with a division...
Could you help me figure a solution ?