View Full Version : Expressions causing large values in 7.5c?

02-22-2004, 08:30 PM
I've started to play with expressions to rig some animation. However, I'm running in to an issue when using expressions on lights.

In particular, I set Light Intensity to 0%, and then select envelope. I click on the Expressions tab, and in the boxes,

"Bank Right"

[TB.Rotation.B,Frame +1] < [TB.Rotation.B,Frame] ? 50:0

The "idea" being that when the rotation in the next frame is lower
than the current frame (e.g. "Banking Right"), turn the light on 50% (it happens to be an attitude thruster light).

However, when I close these dialog boxes, the light intensity shows 5000%, and rendering the scene seems to bear this out, as the frame comes out mostly white.

I've performed the same process with the Lens Flare Intensity options, with the same result.

This shouldn't be happening, should it? Is this a known problem/fix?


02-22-2004, 08:57 PM
I hate adding on to my own messages, but its getting more fun. In reading, I found that I can add Expressions under the "Modifiers Tab", as well.

So, I add my expression there, hoping it'll get around the aforementioned error. I tried it both as:

[TB Null.Rotation.B,Frame + 1] < [TB Null.Rotation.B,Frame] ? 50:0

and as the documented:

([TB Null.Rotation.B,Frame + 1] < [TB Null.Rotation.B,Frame] ? 50:0)

When I try to exit the dialog, I get:

Expression Compile Error:
found ',', expecting ' or '&' or he 'Muscle Bone (Primary)' for information on how to create a muscle bone.

Besides the error making absolutely no sense, anything in particular I'm doing wrong?

02-25-2004, 07:49 PM
Well, I found one problem. The value range I need to use is 0.00 -> 1.00, not 0->100. It makes the lights too bright.

However, the expression errors keep coming.

02-26-2004, 01:35 AM
I can't help with your problem, but i figured I'd wish you luck.
Maybe the luck will get the guy with the big brain to stop a moment and give you an answer. Where is he.....:)

02-29-2004, 06:59 PM
Have you tried using the channel follower. I did a quick test with it and it worked fine. brightness increasing when I banked light one way and decreasing when I banked it the opposite way.. Here is my set-up.. you could mess with this..

hope it helps,


03-03-2004, 07:55 PM
Thanks for the tip. Unfortunately, I will be moving on to more complex expressions. At this point, I have a working set for what I want, so I'm guessing my issues are primarily newbie magic.

We'll see :)