Hi,
I'm currently following the Light, Shade and render tuto (which are great by the way) but I'm currently running into an issue.When I want to create a light different which type is different of a line or a point, I got my geometry which dissapear.

I downloaded latest Houdini build and my drivers are up to date.
Win7 64
amd 7970
Houdini 12.5.517

There is currently a problem with AMD cards and area lights when HQ lighting is enabled. Their GLSL driver apparently has a problem with arrays within a uniform block, making it impossible to set any uniforms in the shader. I will take this up with AMD.

ok, thx twod for the quick answer. I will keep normal lighting fo now.

AMD has been able to reproduce the problem. I'll let you know when I hear from them and the FirePro driver version this is fixed in. They normally don't mention which Catalyst driver version it might be fixed in though, so you may need to continue testing Cat 13.9, .10, etc. until the fix is rolled in.

Turns out this was due to a misinterpretation of the GL spec, so I've patched it for 12.5.520. Area lights and environment lights should work correctly again in that build. Thanks for the report!