> Is it possible to optimize blurred reflections when
> you also use DoF and radiosity?

Absolutely yes. When you use DOF or good AA, it's not necessary to average
normals on top of that. In these cases, using only 1 normal is sufficient
for blurred reflections:

normal {
    bumps .3 // Strength of blur
    scale .000001  // Simulating a microscopic bumpy surface
}

As you see, this code is also easier to handle.

You can speed things up further by calculating radiosity separate of the
final render. Try to render your scenes without DOF or AA, just to get the
radiosity values and save them to disk. By doing this, these relative slow
calculations will happen only "once and for all" and not XX or XXX times,
like they do when you activate DOF or AA.. The resulting image will be
nearly identical.


#declare Render_Pass = 1;  // set to 1 or 2

#include "rad_def.inc" // Great setups; easy to use

global_settings {
    radiosity { Rad_Settings(Radiosity_Normal, off, off)

       #if (Render_Pass=1)
            save_file "Illum2-c.rad"
        #else
            load_file "Illum2-c.rad"
            always_sample off pretrace_start 1 pretrace_end 1
        #end
    }
}


Now, lets see... Render-time has dropped a lot by now! Now it's time for
fine-tuning to balance speed vs quality. Here are some quick suggestions:

Try 40 blur_samples for DOF. That's usually enough for me.

In global_settings, set adc_bailout to 1/64 to increase speed in certain
cases + never a problem.

If you want AA instead of DOF and you're using my approch to blurred
reflections, you may need this: +AM2 +A0.0 +R2 -J    This is my way of
setting AA (in the command line bar) and gives superb AA with reasonable
speed. The quality can go higher/lower, of course. If you want it higher,
try  +R3  but if you think, it's all a waste of time (and you don't mind
some noise here and there)  try   +A0.05 +R2    It depends on the scene.

I hope, your rendering will be a lot more fun now!  :o)

Regards,
Hugo

Post a reply to this message