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...