Now that we've got shadowmaps, can foliage be made to cast shadows?

[HMart]

I don't know how things run under the hood, but shadow maps seem to stress GPU much much more than stencil shadows at the moment. On older hardware, it can be a difference between 20 and 50 fps. Even on modern hardware I can hear fans starting every time I switch to shadow maps. If shadows were precomputed and stored in lightmaps, that should give us significant performance boost. I know, it's tons of work to implement even a simple system, I'm not even asking for a feature like this. But with dynamic shadow maps we don't have much choice but bruteforce (i.e. throw raw hardware power at it and hope for the best). At the same time we can achieve similar look with stencil shadows + softening, without such performance impact.

 

Stencil shadows like zergrush said are calculated on the CPU, so is not surprising they take less GPU power, why shadow maps take more performance out compared to soft stencil shadows only the team can explain. But I can guess the engine was optimized to run stencil shadows, so perhaps there's more stuff under the wood making them faster. Shadow maps were implemented relatively recently so perhaps still need more optimization? It also depends on the technique used, some shadow map techniques are more heavy than others, the heavy ones are also the ones that look the best tho.

 

Btw about performance, yes the TDM team can help by optimizing the assets but nothing beats a mission maker, knowing how to well light a scene, for example you don't need to have every light on the scene cast a shadow, in Amnesia and Soma, they make one or two "hero" lights on a scene that casts a obvious shadow, then small fill lights that cast no shadows at all but light up the scene, I don't remember ever noticing the lack of shadows on those games, SSAO perhaps helps on that. Btw this works for stencil shadows has well.

 

About static light maps, forget it, the engine, tools and mesh's would need to be changed for it (second uv set for example), is just like implementing PBR it will perhaps never happen, plus IMO is old tech.

[peter_spy]

Optimizing the assets will definitely help, as mappers can only work with what they've got. I copied my example map to my old laptop (GF GT 740M, i5 2,5 GHz, 8 GB RAM) yesterday, and with previous builds I assumed 30 FPS will be the target for such old hardware. Imagine my surprise, when I saw 50-60 fps in the longest views.

[kano]

Not being an expert, I would assume that shadow maps are very very memory hungry, seeing as you are generating an image from the perspective of every light to see what portions of the scene are in shadow and which parts aren't. In fact I think you have multiple images per light if it can cast shadows in all directions, rather than being a simple spot.