Re: [Algorithms] Sampling vs fitting values over vertices

[Bert P. <be...@bp...>]

This sounds like a standard sampling problem, so all of the literature
with regards to sampling, aliasing, undersampling, filtering and
reconstruction could be helpful? (including a thread IIRC about it
either here or on SWeng)

Ie. that may tell you how many samples you need to be artefact
free, how to best position and maybe subdivide them, using gradients
for better reconstruction, adding a good filter, etc.


> gives compelling improvements, etc.  Searching on the web/archive didn't 
> really find too much (besides D3DX PRT methods that don't say how they 
> work, and still require a texture thus an atlas/usable parameterization, 
> which I don't really want to deal with).

PRT solves an undersampling problem, but a different one; instead of
figuring out what the best lighting params are for a vertex to
accurately represent a face, it figures out what the best lighting
params are for representing the entire incoming radiance (cosine
convolved, optionally bounced/scattered) at the sample location.

It can be done per vertex, in which case it doesn't need a UV mapping,
but then it can suffer artefacts from interpolation or unfortunate
sample locations again; hence it solves a related but different problem
and wouldn't solve your issue (other than smoothing things out perhaps
and thus being less vulnerable to it).


hth,
bert