lights questions

(pazur) #1

Hi,

is it possible to have lights that cast soft shadows in ETQW? Something like the Penumbra shadows of q3map2?

penumbra_00.jpg800x600

What’s the impact on performance if you have many lights visible at the same time?

Paz

(SebaSOFT) #2

Soft shadows (even radiosity) in q3map2 are achieved due the lightmapping nature of the Quake 3 engine. Where every texture shader can have a lightmap stage. The compilation takes this lights and build a lightmap bitmap to apply to all the surfaces.

In ETQW you can achieve that but only for the Terrain mesh (here it’s called “baked shadows”). All other light are generated dynamically by a pixel shader program. The engine doesn’t support soft dynamic shadows as other current generation engines. That’s one of the reasons because ETQW doesn’t have day/night cycles in their maps.

(pazur) #3

OK. Got it… but what about the performance? Any experience?

(SebaSOFT) #4

The only main concern about performance is that light cast large shadows.
The shadow is not that easy as a shadow stain in the wall, is actually a shadow volume, so when you enter that volume, you get shadowed. For ETQW if you avoid creating long big shadow volumes you should be good. Point lights have a max Distance for shadows so, they aren’t generated after a distance.

It is recommended to deactivate dynamic shadows in the terrain and bake the shadows in the baking process, so the terrain is shadowed but doesn’t produce big f****ng shadow volumes.

(pazur) #5

Cool. Thanks :slight_smile:

(timestart) #6

You might be able to make a custom light image (not sure what they’re called) to fake the effect, like the windows in the Valley contaminator building.

(pazur) #7

I think i will stay with standard lights. The main building in my map has just too many windows and lights to apply fake shadows.

(Violator) #8

Something I did a while back with a custom light texture:

Another performance thing mentioned in the wiki is to avoid overlapping light volumes.