OK it's like this, im totaly out of ideas of what to do next for my engine. I got most things allready, allthough in a semi infant state. I have implemented these things and then some, perhaps not to it's fullest potential yet. Versitile render scripts. Stencil volume shadows. Projective shadows. GLSL shader engine. P-buffer rendering. HDR rendering(not finished yet, but it does work). particle system. VBO (works but it's not that solid yet). skeletal animations. advanced sky renderer. and many more little things. Allthough i am going to continue to work on these things to improve them, i want something more, something noone else has (or atleast not so many). Has anyone of you got any ideas regarding this? Teeories, ideas, wishes or problems? Anything goes.

Hmm, post some screenshots and I can suggest things to fill what the screenshots are lacking in.

Even though you can't tell that trough a screenshot(atleast not from this one).

(this screanshot is not one of the newer ones but besides the addition of normalmaps, it's not that different from now, allso keep in mind that what you see are standin objects, not the final ones)
My engine is not a dedicated game engine, it's more of an versitile renderer that alows for creating a demo game or something compleatly different to be done in hours instead of days.

What im asking for is "cool new things to do with openGL", not "things that enhance or correct the visual apearence of something else".

Something along the lines of particle based depth fog or a new and utterly l33t way of rendering voxels.

It's is allso not only for me, but for everybody.

Depth of field effect?

Enigma

Yea, but thats nothing new, i know how to do that, i can allready do a pretty fast blur effect so i just have to tie it in with the depth value trough a shader, the reason i havn't done that allready is because i really need good HDR rendering and blending, as of now i can only do rendering not blending.
I need that to reduce rendering artifacts when i do the blur effect.

Doesn't anyone has something new.

Parallax Mapping?

Yep, parallax mapping would be the most display quality improving effect i'd say, and maybe some better texture filtering. You said you added normal maps, maybe you could post a screenie of that too.

Also transparency and see-through (and light coloring) glass (using fragment shaders), some nice fog (mayb clouds) and rain effects will be nice. Just the basic natural effects.

Some non uniform fog would be cool.

-parallax mapping is a must-have
-some good postprocessing effects (black&white, depth of field, motion blur, warps..) combined.
-better (soft) shadows (PSM, TSM)
-volume fog
-displacement mapping (if you got the horsepower)
-deffered shading
-ambient occlusion

If i were you I would do real Displacement Mapping (using Vertex Textures), since so few demos or games have done that (only one game as i recall Pacific Fighters)