Warp <war### [at] tagpovrayorg> wrote:
> Slime <fak### [at] emailaddress> wrote:
> > Changing block size is a bad idea. Got it. =)
>
>   Actually I was not talking about block sizes at all. I think Thorsten
> misunderstood me (or I misunderstood someone).
>
>   What I was talking about was that if POV-Ray started to show on the
> preview window each line of each block immediately when they are
> calculated, how much overhead this would cause to fast renders. (This
> would be quite relevant if you are rendering a 100000-frame animation
> where each frame takes 2 seconds to render.)

This makes a lot of sense - I myself have done things like this sometimes
just to see how it runs.

>   Block sizes have nothing to do with this. Determining a good rendering
> block size depends on other things.
>   The larger the block size, the smaller the overhead caused by
> antialiasing, but the higher the probability of an uneven render
> (IOW the higher the risk that threads will start to idle at the end
> of the render while the last blocks are still being rendered).
>   And the opposite: Smaller block sizes increase the probability of
> a very well-balanced render but increase the overhead introduced by
> antialiasing (and secondarily other things).

What prevents you from using different block sizes for different things?
For example, render with a 4x4 block size to ensure evenness (although this
does nothing for overhead...), and then group 16 of those 4x4 blocks
together into a bigger block when calculating antialiasing so that
antialiasing is calculated with 16x16 blocks.

Although that might be getting unnecessarily complex...  another option
might be a 'simple' block mode and a 'complex' block mode - the former
divides the image into large blocks and tries to reduce overhead, the
latter is for rendering complex scenes that take a while and run the risk
of uneven renders and/or have complex needs (e.g. sophisticated AA, or the
different-block-size idea I presented above).  That said, 'simple' and
'complex' are subjective...

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