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Fixed the noisy/aliased shadows for Parallax Occlu

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I'm thinking of buying this XFX GeForce 8800GTS for GBP361.47. Whilst it'd be nice to have the GTX variant I'm expecting the GTS to be sufficiently powerful for my needs (read: faster than the reference rasterizer) and by not blowing my entire savings on a GPU now will make it easier to buy another next-gen one next year sometime... That and I'm half expecting my PSU to explode just by looking at an 8800, so I might have to spend another GBP50 on a decent PSU [oh]





As the above images show I fixed the shadow aliasing/noise issue I mentioned in my previous journal entry. Yay.

The shadow tracing starts at the current texel and early-out's if it intersects with the surface. The code doesn't pay any attention to where it intersects, just that it does or does not. In the process of debugging I output the length of the intersection offset and found that the aliased pixels were all very close intersections. A bit more checking and the assumption became that it was either intersecting with the source(possibly courtesy of filtering rules) or it's immediate neighbours (more likely).

I'm using a traditional 8bit height-field for this source data, therefore we are working on a 4e-3f granularity. Offsetting the initial height of the shadow ray by this quantity generates the "clean" pictures above [grin]


Next time I'll see about posting a summary of the performance complexities for the various effects. If I can work out how to post a table of figures in this journal that is...
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Wow, those corrected images (well, not the debug one) look simply spectacular. I can't wait to see this implemented into a more complex scene.

Awsome work [smile].

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I'd like to test this against a more complex scene, but my modeling skills are sufficiently rubbish that this might not happen [lol]

I probably should look at buying in some decent artwork for this book...

Jack

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Have you seen NVidia's TransmogrifyingTextures Pack? I'm not sure what the license is, but it may well allow you to use it, and they have some pretty impressive textures in there.

Combining one of the bumpmaps in the pack on some terrain could yield some nice results, I think :).

Of course, actual artwork would work even better...

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Looks awesome. I have the 8800GTX and can say its worth the extra cash if you can afford it. It's a fair amount faster than the GTS. I would look at BFG cards. I have had a few and never had any issues. A friend of mine has a BFG also and likes his. Their fans seem quieter than XFX's fans from what I been told...

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Quote:
Have you seen NVidia's TransmogrifyingTextures Pack? I'm not sure what the license is
I grabbed my copy of that download a long time ago - it is indeed a good resource that I'd forgotten about. I checked the licence and my interpretation is that I wouldn't be able to use it for the book [headshake]

Quote:
I have the 8800GTX and can say its worth the extra cash if you can afford it
I don't tend to be too fussed about performance above 'real time'. If I could use it to play 1600x1200 games at top (or near top) level of detail then that's absolutely fine for me [grin]

Also, if I get a single cheap(er) GTS I suppose I could either buy a second GTS later on and get SLI/AFR, or I could get another model in a years time - say a second generation D3D10 part, or a first-gen D3D10.1 part...


Cheers,
Jack

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