Sun/Sky system, scene scale

[jonmoore]

When I first learnt V-Ray back in the day I was taught that it was best to have the scene scale set to centimeters to get the best from the Sky/Sun system as this meant that I wouldn't have to rescale strength parameters or set the physical camera with unrealistic exposure settings.

These days I nearly always use HDR's to light exterior shots so it's been a long time since I've used the Sun/Sky system. Do the same scene scale rules still apply for absolute physical accuracy, and are these scene scale rules the same across Max, Maya and Modo (I was taught the scene scale requirements originally with the Maya version of V-Ray)?

[vlado]

When I first learnt V-Ray back in the day I was taught that it was best to have the scene scale set to centimeters to get the best from the Sky/Sun system as this meant that I wouldn't have to rescale strength parameters or set the physical camera with unrealistic exposure settings.

This has never been true; the sun/sky/physical camera combo works correctly regardless of what units you have chosen.

For HDRs, they don't have any meaningful physical illumination scale, so do whatever works.

Best regards,
Vlado

[jonmoore]

Cheers, good to know Vlado.

You need to speak to the folks at Lynda.com as they're the ones who mention the importance of scene scale when using the Sun/Sky system in Maya.

http://www.lynda.com/Maya-tutorials/.../126058-2.html