Just distribute the source code, I do not think the author has a problem with it. My personal favourite are cascaded shadow maps. They work very well ... but they are expensive. Nevertheless this is the price you want to pay for decent shadow maps.
Which source did you try?
If you want, I can send you the ShaderX-version (being the author of that article :)...
LiSPSM and TSM actually achieve practically the same effect, except that the parameter in LiSPSM is calculated to guarantee a maximum error in z. It should be noted that warping techniques work best with directional lights, and for situations where the light comes from rather overhead.
"swimming" shadows are unfortunately unavoidable if you want to make decent use of texture space, since you have to adapt the shadow map to what you actually see...
Michael
If you want, I can send you the ShaderX-version (being the author of that article :)...
LiSPSM and TSM actually achieve practically the same effect, except that the parameter in LiSPSM is calculated to guarantee a maximum error in z. It should be noted that warping techniques work best with directional lights, and for situations where the light comes from rather overhead.
"swimming" shadows are unfortunately unavoidable if you want to make decent use of texture space, since you have to adapt the shadow map to what you actually see...
Michael
well I tried the LiSPSM calculation for my directional light, but I didn't like the results. It is great for screenshots, but like you mentioned, the swimming artifacts, when you're moving, make the shadow look even worse if you ask me. I am now doing some more advanced cascaded shadow maps with variance and projected shadows into it, and I might add the LiSPSM calculations afterwards to it again, because the quality should be much better then, and I hope the swimming will be less noticable.
I heard that with TSM you can smoothly change the transitions. Is this correct, and does this work nicely?
Regards,
Kenzo
I heard that with TSM you can smoothly change the transitions. Is this correct, and does this work nicely?
Regards,
Kenzo
Quote:I heard that with TSM you can smoothly change the transitions. Is this correct, and does this work nicely?
Yes, there is a parameter which determines the focus region. When light and camera become more parallel, I set this parameter to a higher value.
What I'm also doing is to cut the view frustum before shadow calculations. This means that objects far away don't cast shadows anymore, but it really helps improving shadowmap resolution.
if the quality of lispsm or tsm is not good enuf then use csm (the downside is they are slower)
Author
I think CSM's are great because they're cachable and they seem easier to implement. Does anyone know of a tutorial for them?
Quote:Original post by wolf
... there will be an article in ShaderX5, but this book is due in December 2006.
I found a paper about CSM right here it's called "Parallel Split Shadow Maps".
They mention that they will consider using MRT for CSM shadows in future. I have no clue how that should work, since you want different geometry for each shadow map, but maybe they are just way more clever than I am.
There's also another paper from the same university called "Generalized Linear Perspective Shadow Map Reparametrization" which (as every other algorithm before ;-) claims to create lower antialiasing artefacts. Has anyone tried that one?
There is also Subdivided Shadow Maps. Their video looks great, but I haven't had time to read and implement the paper.
hmm fast server for the "Parallel Split Shadow Maps" paper. Can someone provide a link or mirror to this pdf, because I can't seem to download it. Will take ages.
Thank you,
Kenzo
Thank you,
Kenzo
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