[Radiance-general] animation

[Peter Apian-Bennewitz]

atelier iebele abel wrote:
> 
> Hi all,
> 
> I am rendering an animation of an interior scene. At this moment one
> frame takes about half an hour to render(*), with fine results per
> frame. When I view the frames as an animation however, the artifacts are
> "unstable". It looks like Radiance renders shadows,
> reflections(specularity) and indirect illumination in a random way.
> Sometimes objects also get different color intensities in the rendered
> image, as if they were lit in a (radical) other way.
> I have rendered a lot of still images in Radiance and never noticed that
> two renderings with exactly the same geometry, render-options, viewport
> etc. results in slightly different images (!).
> How can I solve this? Does anybody knows how to render without these
> "moving artifacts"? Is there a random thing in Radiance that we can turn
> off ?
stochastic calculations are used as MC integration in specular and
ambient calculations and for efficency reasons in direct and secondary
light sources. Your vastly different images sound like a too optimistic
approximation in the direct calcs (dt, dc options- how many light
sources are there ?), but most animation suffer from varying ambient
calculations. If it's only a walk-through animation with a fixed scene,
it helps to pre-run along the path doing every n-th frame (n=2..10) with
a small resolution and fill an ambient file. 

Very probably rendering times will go up for artifacts to go down - You
may want to try the pinterp program to interpolate between frames,
although it uses more diskspace and the controlling script/program gets
more complex (especially using multiple machines to render on).
Interpolation breaks with reflecting/refracting surfaces too, but
otherwise speeds up animation quite a bit.

-Peter

> 
> Regards,
> 
> Iebele
> 
> (*)  Below are the settings I use for the rendering. I know that I can
> increase the quality using different settings, but that is not the point
> here. My point is that the overall solution has too many, and
> unexpectable differences between  rendered images.
> 
> The settings are (as they appear in my ran file):
> DIRECTORY  = /disk11/ani01
> OCTREE = glow.oct
> VIEWFILE = ani01.vp
> START  = 1
> END  = 448
> BASENAME = /disk11/ani01/ani01%03d
> DISKSPACE = 250
> OVERSAMPLE = 4
> INTERPOLATE = 0
> RESOLUTION = 720 576
> render = -dp 1024 -ab 1 -ad 1024 -ar 2048 -as 512 -aa 0.2 -lr 1 -st 0.01
> -ps 8 -av 20 20 20
> pfilt  = -r .7
> 
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