Inaccurate output findglare

The accuracy of the de output of findglare seemed to be limited by its formatted output.

For example, when modelling a car headlamp with a diameter of 0.1 m at distance of a 100 m the sold angle is 7.85398163e-07 sr. This solid angle will be printed by findglare as 0.000001. So incorrect data is used for further analysis. (See also “Rendering with Radiance”, section 7.4, for a similar situation).

This can be easily fixed by the makers of findglare by using e-format or g-format with sufficient precision for data output.


Hi Johan,

Thank you for pointing this out. Sorry for the delay in our response – your post was held up by the “spam detector,” so I only just saw it. I have made the appropriate change and checked it into CVS. It should appear in the next release, or you can download it directly from here.

We have recently found other issues with findglare, particularly in how it computes indirect illuminance. We have not had time to correct these inaccuracies, but you should be aware they exist.


Hi Greg,

Thank you for fixing this problem. I can make better glare calculations now.
In general, the accuracy of all Radiance commands with data output should not be limited by formatted output.
By the way, Radiance is a great toolkit! Thank you for developing it.


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