Overture calculation

radiance-general
1

I've been tracing a relatively small number of rays through a model, and when I added more rays, one of the previous illuminance values changed by 9%. Apparently, the ambient file had been inadequately populated.

OK.

So, I need an overture calculation. I think the easiest way to ensure a fairly complete ambient file is to generate small images. I could do six orthographics at maybe 200 pixels long-ways, or a trace a more comprehensive grid, or ... Any suggestions?

···

--
Randolph

2

So, I need an overture calculation. I think the easiest way to ensure a
fairly complete ambient file is to generate small images. I could do six
orthographics at maybe 200 pixels long-ways, or a trace a more
comprehensive grid, or ... Any suggestions?

In general, it is the best to use the same view settings for the ouverture calculation as you will use later for the renderings. You want a refined ambient cache for areas which are actually of importance for your final renderings, so it does not make sense to first create detailes ambient data for the whole scene, if you want to render only one image later. If you are targeting at creating an animation, just skip frames and render a low-res of every 10th or so.

Cheers, Lars.

3

If you aren't generating an image, but are (as you say) just sending a small number of rays, just run your calculation twice, saving the results to an ambient file. Should be very quick the second time through.

-Greg

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From: "Lars O. Grobe" <grobe@gmx.net>
Date: August 9, 2011 1:56:55 AM PDT

So, I need an overture calculation. I think the easiest way to ensure a
fairly complete ambient file is to generate small images. I could do six
orthographics at maybe 200 pixels long-ways, or a trace a more
comprehensive grid, or ... Any suggestions?

In general, it is the best to use the same view settings for the ouverture calculation as you will use later for the renderings. You want a refined ambient cache for areas which are actually of importance for your final renderings, so it does not make sense to first create detailes ambient data for the whole scene, if you want to render only one image later. If you are targeting at creating an animation, just skip frames and render a low-res of every 10th or so.

Cheers, Lars.

4

Thanks, Lars. That helps.

···

On 2011-08-09 01:56:55 -0700, Lars O. Grobe said:

So, I need an overture calculation. I think the easiest way to ensure a
fairly complete ambient file is to generate small images. I could do six
orthographics at maybe 200 pixels long-ways, or a trace a more
comprehensive grid, or ... Any suggestions?

In general, it is the best to use the same view settings for the
ouverture calculation as you will use later for the renderings. You want
a refined ambient cache for areas which are actually of importance for
your final renderings, so it does not make sense to first create
detailes ambient data for the whole scene, if you want to render only
one image later. If you are targeting at creating an animation, just
skip frames and render a low-res of every 10th or so.

--
Randolph

5

Ohhh... Thanks--I'll try that.

···

On 2011-08-09 08:47:47 -0700, Greg Ward said:

If you aren't generating an image, but are (as you say) just sending a small number of rays, just run your calculation twice, saving the results to an ambient file. Should be very quick the second time through.

--
Randolph