3-phase/5-phase method: is a high -ad value for vmtx_par or dmtx_par?

[sarith]

@catsquito

So for the less complicated room geometry, daylight matrix plays the main role in the calculation, so we only need to set a high -ad value for dmtx when running HB+. In the other way, for a more complicated room geometry, view matrix would participate more than it does in a simple scene, so we need to adjust -ad values in both vmtx and dmtx. Did I understand it correctly?

The calculation, and impact on accuracy of, vmtx and dmtx are independent of each other. So, you need to increase/decrease ambient parameters for them based on the complexity of their geometry. I don’t think it is appropriate to assume that one matrix is more important than the other based on complexity of geometry in a specific context.

@catsquito

Theoretically, does the -ad value connecting to vmtx or dmtx differently have an impact on annual results (average UDI, DA, sDA)?

Yes to all metrics. DA and sDA are measures of daylight sufficiency. UDI also accounts for excess daylight, but this is supposed to be on account of direct sun than diffused daylight. So if the ambient values in the calculation are lower than required, there is a likelihood that those metrics will be affected.

@catsquito

I am asking this because for the same geometry configuration and material, sDA and DA results from Annual Daylight Recipe are much smaller than the results from 5-phase recipe, UDI results are quite similar though, while ASE is always zero.

As I mentioned in my previous post, I’d rather look at the actual commands in the .bat file, than what the recipes are doing. ASE is likely zero because in the direct-sun part of your calculation, the entire scene might be getting blacked out.

@catsquito

I guess radiance parameters don’t have too much to do with the annual results in different recipes, and it is more likely due to materials, but I am not very sure…

The radiance programs used for the annual calculation in HB[+] don’t employ ambient caching algorithms and rely on Pure Monte Carlo calculations instead. So, several paraters like -aa, -ar, -as etc. have no relevance.

Regards,
Sarith