Shadowing Techniques

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6 comments, last by Matt Aufderheide 16 years, 6 months ago
After almost two hours on the net I've compiled a list of Shadowing Techniques for my third year project at University: -Radiosity -Ray Tracing -Dark Mapping -Light Mapping -Stencil Shadowing -Plane Projected Shadows -Projected Shadows -Vertex Projection -Shadow Mapping -Bump Mapping -Horizon Mapping Is there any clear holes im missing in terms of currently employed/state of the art techniques? I think I have pretty much all categories but would like some input on other techniques which people may have used or heard about. Any help will be greatly appreciated Thanks Neutrinohunter
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Bump mapping as shadowing technique?? As far as I can remember, bump mapping is used to simulate relief on surfaces without using an overdoses of triangles. there are some self-shading issues with bump mapping, but I don't think bump mapping can be used as a shadowing technique.
Bump mapping is a name used to refer to a set of shading techniques (i.e. normal mapping) but AFAIK has nothing to do with shadows.
Radiosity is used to compute some indirect lighting effects, but often shadows are computed with other algorithm (like raytracing).
If you want to put Global illumination algos into the list then you should also add:
-photon mapping
-path tracing
-bidirectional path tracing
-metropolis light transport
-ambient occlusions
-Precomputed Radiance Transfer
and most probably a few others.

Add anyway Beam Tracing to the shadowing algos.

P.S. What is Dark mapping?

EDIT: In addition, if you want to take variations of the same tecnique into account, be aware that there a lot of different implementations: there are at least 10 different shadow mapping variations, for example...

[Edited by - cignox1 on September 27, 2007 11:51:12 AM]
there are a bunch of threads regarding shadows. Nowadays most AAA titles use Cascaded Shadow Maps. Just google for this term or read the ShaderX5 article. Parallel-Split Shadow maps are cascaded shadow maps with a clever way to determine the size of the slices. So this article covers the determination of those slices.
I suppose it depends on what you class as a shadows, whether to include some of the Mapping techniques.

Bump mapping can have an effect where it makes a shadow-like siloheutte on the surface (similar to self-shadowing) in some programs which I have seen and articles I have read. Though this may not be a correct interpretation of those sources :) I'm not an expert.

I think it was Ysanega, who developed this technique. I'm not sure, I sent a PM asking for some information on it, which I believe he posted in a topic not long ago.

The idea was to catalogue various different types (projection shadows, planar shadows, volumetic techniques,mapping techniques, global illumination) and pick a few of them to use in a shadowing project I have at University.

Thanks for all your replies, I still welcome any other information to add
Jamie
Some of the most advanced bump mapping techniques can also render a shadow of the 'bumped' portion of the texture. That aside, there are (as you most probably already know) different algorithms targeted to real time apps rather than off line apps... I don't know if your project should consider that...
My project is to review and demonstrate state of the art shadowing techniques. As far as I know there are at least 9 - 12 different techniques with like 50-60 variants, so I'm not sure I will address with that sort of detail.

However, I think all these methods can be condensed to 3 basic techniques: raytracing, shadow volumes and shadow maps.

I think you'll find that all other versions and so on are essentially variations or subsets on these main methods (I dont know about the various global illumination methods like PCRT, etc...I dont consider those really shadowing methods).

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