[Radiance-general] Deterministic calculations with Radiance

[Greg Ward]

I don't think repurposing PostgreSQL code is going to be useful in this 
case.  We'll be comparing floating point values within some delta, 
probably over large images, and the existing tools should be sufficient 
for that (pcomb, etc.)  We just need to create a few dozen test scenes, 
a Makefile for generating results, and a generic script for comparing 
them against the official results for each regression.

It's probably a 2-4 weeks effort to do it right.  It's always a 
question of who has the time, I suppose.  We could make assignments, 
each volunteer testing out their favorite aspect of Radiance.  Anyone 
want to step forward?

-Greg

> From: Christopher Kings-Lynne <chriskl at familyhealth.com.au>
> Date: February 10, 2005 1:38:48 AM PST
>
>> Yes, I could see doing this.  We would of course be accepting 
>> differences between versions and machines to some tolerance, but it 
>> should be sufficient for spotting any major regressions in the code 
>> or between releases.  The trick then is to have enough well-designed 
>> test scenes to cover all of the basic and some of the more esoteric 
>> features of Radiance.  (The "prism" and "BRTDfunc" primitives spring 
>> to mind.)
>
> I am a developer on the PostgreSQL database, and we have a full suite 
> of regression tests.  We use diff to compare actual vs. expected 
> results. Perhaps we could borrow that code.
>
> We have per-platform floating point files that we need to use to allow 
> for differences in IEEE implementation between some platforms.  ie. 
> -0, etc.
>
> I was personally thinking for my own project checking that as I make 
> changes to this big script I have, I don't affect other stuff.  
> However, having a regression suite for Radiance seems like something 
> that's way overdue for a piece of software that needs to be correct 
> for legal purposes :)
>
> Chris