Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Feature Requests => Topic started by: Artisticpixel on 2023-07-06, 12:57:18

Title: set lumens per 30cm/ 1ft at a certain width
Post by: Artisticpixel on 2023-07-06, 12:57:18
Not sure if this has been asked before but is there any way we could have a setting where the light would scale up/down its lumens if the light rectangle remains constant in width but becomes longer eg, the LED is 1cm wide and 450 lumens at 30cm- that becomes scalable dependent on length ? would save quite a bit of time especially when it can be dialed in once and then left to work throughout the scene on multiple length strip lights. At the moment I have to use this calculation on each strip light :: length divided by 30 x 450 = lumens needed
Title: Re: set lumens per 30cm/ 1ft at a certain width
Post by: Juraj on 2023-07-06, 13:02:44
After setting initial amount in Lumens, change to Watts. It will convert the value and the Watts are measured per square area so the total intensity will scale up & down with size change.
Title: Re: set lumens per 30cm/ 1ft at a certain width
Post by: Artisticpixel on 2023-07-06, 13:12:18
After setting initial amount in Lumens, change to Watts. It will convert the value and the Watts are measured per square area so the total intensity will scale up & down with size change.
Perfect, thank you. BUT.. when I go into the light lister and change from lumens to default it changes every single light to 69.9 W no matter the lumens, if I change it back it still shows the correct lumens- should this be the case ?
Title: Re: set lumens per 30cm/ 1ft at a certain width
Post by: Juraj on 2023-07-06, 14:22:40
It should be like that if you used your formula previously as you mention in your first post. And Corona should do conversion correctly both ways unless there is bug. (Only exception is when you reach 99999 value)

Example I just quickly tried:

Light A: 100cm x 5cm 5000 Lumen = 46 W/srm2
Light B: 200cm x 5cm 46 W/srm2 = 10000 Lumen

Works as expected. Watts per surface stay constant, Lumens as direct total luminosity adjust accordingly.
Title: Re: set lumens per 30cm/ 1ft at a certain width
Post by: Artisticpixel on 2023-07-06, 14:49:25
It should be like that if you used your formula previously as you mention in your first post. And Corona should do conversion correctly both ways unless there is bug. (Only exception is when you reach 99999 value)

Example I just quickly tried:

Light A: 100cm x 5cm 5000 Lumen = 46 W/srm2
Light B: 200cm x 5cm 46 W/srm2 = 10000 Lumen

Works as expected. Watts per surface stay constant, Lumens as direct total luminosity adjust accordingly.

Thanks, just did some more tests and yes it works as expected, I still cant seem to grasp how it works out the initial Default number but seeing it work fine is good enough for me. Thanks for your help.