pouët.net

hi,

there are a lot of techniques to implement shadows in openGL (volume shadows, shadow maps, approximate shadwos, ...)

which one is easy and short to implement?
and maybe anyone got a code sample for me? :)

thanks!

Ack, use flipcode or something =)

get hold of john carmacks quakecon speech videos, he talks alot about the pros and cons of different gl shadowing techniques.

http://www.codesampler.com/

well, i thought you guys have some opinions too. ;)

thanks anways. :)

It would be interesting indeed. Anyone? :)

opinions I mean, not sourcecode :)

Why would you want to use shadows in a demo? I think they are only good for 3d fly-bys - and we all know how dreadful these are. Safe yourself some time, forget shadows, concentrate on more abstract objects.

as long as it serves design purposes, it's potentially interesting.

or even just for curiosity's sake :)

this may sound surprising, but its nor for a demo. ;)

if it's not for a demo, that is very surprising. all other threads are purely about demos, demos and demos only.

have you no shame!

some real raunchy softshadows would be nice to see

stelthz: abstract objects don't have shadows?

stelthz: wow, you really have -no clue-, do you?

abstract objects are usually envmapped and rotate slowly, like in most 64k intros. They dont have nor cast shadows ;)

Dude, looks like i pushed some buttons there, eh?

Keops understands.

Abstract objects with shadows
More abstract objects with shadows
(in 64K)

so how were the shadows made in these two demos?

Shadowvolumes

My opinion: shadow volumes :-).

Except if you plan to use some high resolution shadow maps where you can do some nice stuff with the zbuffer values and get a nice soft shadow... but thats definitelly not applicable for a demo since most people here will thumb down it if they cant run it in their PC because of their PCs suckyness.

3dmark2005 has nice shadowmaps

Ok it requires an überexpensive card, I stfu :)

ok, so does anyone know of a short simple implementation of shadow maps or a tutorial?

Search the NVIDIA website, plenty of papers and sourcecode about shadowmaps and other shadowing methods.
ATi also has one or two examples with shadowmaps.

I would go for shadow volumes unless you're pushing a LOT of geometry, in which case the overhead might be too much. With shadowmaps, it's often quite hard to get them looking good in general cases.. although I suppose for a demo you can get things working well just for a particular scene.

ok, shadow volumes sound very neat.
so do you know of a short simple implementation or a tutorial? =)