[Radiance-general] animation

[atelier iebele abel]

Hi Peter,

Your reply includes some critical remarks on the subject.
I will try to answer them from my point of view, within the context of
animation (please remember that  my project would have taken about 2250
hours (14 weeks) on 4 1000Mhz cpus when rendered as animation, and still
having significant artifacts).

> Will it work generally ? With specular/reflecting surfaces and shadows ?

Transparent surfaces (like glass) seem yet another problem for me....

What I will try is using a radiance picture without radiosity and then
change the value of each pixel a little depending on the normal orientation
of that pixel. When the normal points upward, I make the pixel just a liitle
brighter, facing downwards, the pixel becomes a liitle darker, etc.
This is needed for my application, since a non-radiosity interior image
looks very flat (a cube in such a case is hardly recognisable as a cube).

My approach is a little like "vloeken in de kerk" (dutch: using bad language
in the church):  I am aware of that.  Believe me: I hardly dared to bring
the topic into this discussion (...).
We want to use animation in combination with "real" radiance images in the
editing of a project (so we don't use bad words all the time :).
The animation is meant to provide a way of having some insight in the
spatial behaviour of a building.
When we use another renderers besides radiance however, these images don't
look very good (they are _different_ ). To mention: luminaires, sky
defention, the appearance of 'white' surfaces etc, the overall feeling of
light (even if ab=0 I feel light in the scene -  I never felt light in
Lightscape, but ok, that was about 8 years ago).

> Will 2d processing be validated to have the same trust as Radiance now
> has ?

When I program this 2d processing: certainly not!
That will be far beyond my skills.
I give it a try, when it does what I imagine I am satisfied.
If anybody can do it better: please!!!

> Maybe you're on the way towards Wavefront, Renderman or whetever
> there is for professional animations, without actually getting their
> speed or quality, but loosing a lot of Radiance.

I don't want to use different rendering tools within one project. As I said:
we will use radiance anyway.
Other renderers require other ways of getting the data right. This means:
much extra work within the same deadlines.
There is something else. I worked with a lot of renderers (except renderman)
and what I like about radiance is that we are able to write scripts for
complex situations. For example we did a project in which there were 4
variations on 4 building types on 2 different location-types.
We rendered two views from every possible combination and put these images
in a simple user-interface. The scripting took 2 hours, the renderings
overnight. Is there any renderer that allows me to do this? I really rely on
Radaince in such cases.

> IMHO, speedups for animations in Radiance will be a side effect when/if
> the core rendering is enhanced (photon map, direct caching maybe) and
> validated. Meanwhile, Greg's recommendation of using brute force and
> some more CPUs sounds right to me.

To me also. Maybe I am wrong and the whole idea will not work.
I will be happy to show you some images after I finished  my homework :)
I am very curious what the result are. My opinion is very humble in this....

Yet there is another application where I am thinking about: when I know
which object/modifier is represented by a pixel, I easily can put each
object-pixel in a different layer ( as in photoshop) and enhance them
seperately.
This is very usefull in video, for example to dim oversaturated colors a
bit.

> Or you may try to render texture maps through Radiance, which are then
> glued onto surfaces and final frame rendering is done by other rendering
> engines

Why not Radiance in this case?

> (which may have more inter-frame coherence too). At least the
> interface would be well defined.

Last but not least: Is there a way to do this ? I read some discussions
about this topic, and it seems to me that it does not really work (?). Or am
I wrong here?

Just to mention within this context. Something simular to the above: we work
on 360o panoramic views (2048x2048pixels, rendering times about 10 hours for
one oversampled image, but that doesn't hurt for a single image), which we
map on a slowly rotating cylinder in OpenGL, and then we render these frames
to file. These result are quite good (and fast and reliable/trustable). The
only bad thing is that I am not an educated programmer, and the application
crashes as soon as I write an image to a file... So I've seen the results
only in the application, not on video yet.
Time will fix this sooner or later.


> Your mileage may very.

I can't translate this sentence, mileage is not in my dictionary (?)


Regards (nice discussion),

Iebele