> Tor Olav states there that his distance estimation function has to be improved
> likely. And Waggy explained the idea behind this functions but I was to stupid
> to comprehend this at first reading. In fact the original code of Tor Olav
> rendered 31 minutes, but yielded a very smooth superset of the mandelbulb only.

The Max_Iterations limit will control how smooth or detailed the surface 
is. 64 is really a bit OTT for a render that shows the entire 
mandelbulb, I primarily put it that high so that when you zoomed right 
in there was still a lot of detail. You might try reducing it to speed 
things up.

> Here is the image using the distance estimation function proposed by Scott. I
> still observe some problems (there seems to be some kind of bridges at the
> right). To the left is an visualisation of the mandelbulb function as a pigment
> function taken at the middle of the container object. It uses
>     color_map {
>        [0 Red ]
>        [0.5 Yellow ]
>        [1 Cyan ]
>     }
> I rendered this to get a better understanding of the distance estimation
> function (orange to red here). Note that Cyan indicates negative values close to
> zero here (and not close to one).

That's a good idea, I hadn't thought of that - it's interesting to see 
what the range of values actually is.

> Rendering time was 18 h 28 m. I think Scott's GPU approach will be a little bit
> faster then POV.

Well mine (obviously) depends on the GPU you have available, if you have 
a card older than a year or so then it's highly probably it will take an 
infinite amount of time to complete :-) On a modern nVidia 970 it can 
manage of the order of 10fps, which means after 5-10 seconds you've got 
a nice anti-aliased image (once you stop moving the camera it 
continually averages the new frames together).

Post a reply to this message