Cineversity

Hi

I am using Cinema for analyzing lightpattern on ground in different applications. Is there any way to get isolux curves on ground plane in Cinema? Currently I have to make same setup in other program and import curves as texture to the Cinema.

Hi Janne Lindholm,

I’m not aware of a direct way to get this, if you could share a file…
Any curve that is produced is based on a very specific position in relation to the light source. Those parameter need to be kept in relation, a projection in distance will distrot its “readings”. I guess we agree here. Having said this:

The following is more a graphically based idea, not even pretending that this would recreate exact curves.

If there is anyway to get the light data as IES, that could be read in Cinema 4D.
https://help.maxon.net/#OLIGHT-LIGHT_GROUP_PHOTOMETRIC
With this you might test this with “Sketch ‘n’ Toons”, as in the scene below.
The results need to be baked as texture, as it would otherwise change if the camera position changes. This can be done by using the S’n'T shader Cel, tehn reload to the bake.

Scene File _01 + _11
https://www.amazon.com/clouddrive/share/T2gOSQLqPX3gjvcZOUwihejqjg9HVv26TBXMgtkgEaw?ref_=cd_ph_share_link_copy

Screen Shot
https://www.amazon.com/clouddrive/share/RKwZnj9gJTn2sb4SZmFWmSQ6tRkKzWJvacCeisugf9k?ref_=cd_ph_share_link_copy

Bake Screen Shot
https://www.amazon.com/clouddrive/share/vLpChgLGLDF0kGVB57P5ztKGusCnFYDF1pdHZ52PD64?ref_=cd_ph_share_link_copy

All the best

P.S.:
For everyone else interested about it
https://youtu.be/k8BayPSRcGI
https://iarc.uncg.edu/elight/learn/qualitative/la_sub/isolux.html

An undocumented feature might be useful, as the Attribute Manager [Light source active] > Details allows for a Gradient. Here, so my exploration, the Gradient needs only one color, and presents then the brightness in rainbow colors, as in H: 230º, S: 97%, V: 50% As setting while using IES data. This is just an idea, your values might differ.
https://www.amazon.com/clouddrive/share/0wAq7hZOyIgOu4cguohwRxQWk4PRHkz3xtakqwtegwn?ref_=cd_ph_share_link_copy

I assume that the isolux curves can or are based on IES. Again just an assumption. With the mehtod above, the interaction with a surface would limit its precisition, as the cuvers measured are normally clean air (my terms, nothing official) measurements account for the numbers of each curve.