[Radiance-general] another water question

[Gregory J. Ward]

Hi Rob,

I can't say I've done it before, but the usual way to animate things  
in Radiance is to generate a different model at each time step.   
There's no reason you can't modify your material descriptions as you  
do this, changing real arguments on your texfunc primitives, which  
are then interpreted by the.cal file to modify the origin and other  
parameters associated with a water texture.

You could also modify the .cal file at each step, but I advise  
against that approach, as it won't work reliably with ranimate unless  
you gave the .cal file a unique name for each time step, at which  
point you will have to modify your material primitive, anyway.

Sorry I don't have any ready examples for you.

-Greg

> From: Rob Guglielmetti <rpg at rumblestrip.org>
> Date: May 25, 2006 8:42:36 AM PDT
>
> Gregory J. Ward wrote:
>
>> You probably want to add a time-dependent wave texture to your   
>> water's surface as well, since most of what makes a person  
>> difficult  to see while underwater is the reflections off the  
>> surface, which are  constantly in motion.  I recommend doing an  
>> animation for that reason.
>
> Thanks Greg for the excellent tips on modeling water, but I'm  
> afraid you have opened up another can of worms with the last  
> paragraph, above.  You mention a time-dependent wave texture. (!)   
> This sounds rather like some sort of variable texture that  
> modulates the surface normal based on a time input.  One could  
> script up a run of images and for each frame that water material  
> would be modified by a random deformation that is keyed to  
> timestep?  This sounds like an interesting application, and I was  
> wondering if you had a framework for such a material description.   
> cal files are really something I'm trying to understand more, and  
> each example helps a little bit more.
> - Rob