Creating a light meter for CG scenes


#1

I’ve been doing a lot of reading about lighting and thought that having a light meter in my CG scene would really be useful. I’ve created an expresso expression to do just that. Here’s how you use it:

  1. Download the xgroup from my website: www.briancbarnes.homestead.com/files/light_meter.xma

  2. Place this xgroup in your C4D library\xgroups folder.

Now, in any scene where you have a light that you want to check:

  1. Create a NULL object as a child of the light you want to check. This NULL object defines the location in your scene where you want to sample the light.

  2. Right click on the light, and add an expresso expression.

  3. In the expresso editor, use the FILE menu to load the light_meter.xma xgroup.

  4. Right click on this xgroup, and select “unpack” so that you can see the two “results” boxes.

  5. The two results boxes will show you the color and intensity of the light at the location defined by the NULL. The values range from 0 (0%) to 1 (100%).

  6. Note that the references in the XGroup for the light and the null object are relative references, so you can ctrl-drag this expresso expression to other lights (after adding child nulls to them) and then double click the expresso tags to check the light from each of the light sources in your scene.


#2

Thank you! - will try it out right away:)


#3

hey way cool. thanks…:thumbsup:

(off topic…but this reminded me…i know i shouldn’t and it maybe a newb question but does anyone have an easy way to measure distances from one object to another?)


#4

@Flingster: Paul Everett wrote a plug that does exactly what you are looking for.


#5

thanks matey…:beer:


#6

you can also use the distance node.

cube----
distance node–result node.
cube-----

pretty simple.


#7

thanks for this one:thumbsup:

bcbarnes: Again off topic are you the bcbarnes who had an excellent thread on dvgarage about bools in cinema…cos i can’t find it on there any more…if you are any chance you kept it? Oooh and sorry about diverting thread again…but good work…nice idea.:buttrock:


#8

flingster,

It might have been me - I visit that forum from time to time and always use the same "handle" when possible. I had a lot of questions about boolean objects when I first started using C4D. Of course, the new "better bool" will make most of us look at them all over again :)

#9

cool any chance of some input on this thread…its got me foxed…and since in mighta been you. i think the poster had an ape handle pic on dvgarage…no offence intended…but you ain’t got one…so maybe i’ve mixed ya up…anyways the thread.

:wip:


#10

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