Thorsten Froehlich wrote:
> 
> Yes, but ignore the beta 7 implementation details as they are not complete
> yet.  The main idea was to get some feedback on the changes, but of course I
> didn't take into account the problem that was left in there.

Ok, that's clear.

> What is happening is that the "adaptive max_gradient technique" as Mr.
> Suzuki calls it, is now always used partially.  Unfortunately this causes
> the max_gradient to grow and thus cause the slowdown people report with
> evaluate.

I think that's what you can influence with the second and third parameter
of 'evaluate', i was just starting to explore it.

> > Then one thing wonders me: what's the difference between the first
> > parameter of 'evaluate' and the max_gradient value if both are specified?
> 
> I have a good idea how the code works, but not what the individual values of
> evaluate will exactly do to what surface, if that is what you are asking.
> 

Yes, as i understand it, it's a starting value for the estimation
process.  So the following view should be correct:

- with only max_gradient, Povray 'blindly' renders the isosurface.

- with max_gradient specified and using 'evaluate' the max_gradient stays
fixed for the render, but Povray suggests a new value (like Warp described
in the other thread)

- without max_gradient, Povray uses an 'adaptive max_gradient technique'
or 'estimation technique' and uses the first parameter from 'evaluate' as
a starting value.

I think this is also what is essentially written in the isosurface SDL

i will try to work out something for the tutorial (referring to your other
post)

Christoph

-- 
Christoph Hormann <chr### [at] gmxde>
IsoWood include, radiosity tutorial, TransSkin and other 
things on: http://www.schunter.etc.tu-bs.de/~chris/

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