View Full Version : Newbie Expression Theory Question

06-08-2003, 07:59 AM
Why are there bracketed and unbracketed forms of expressions?

World position seems to be only able to be referenced from unbracketed, but it just seems strange to have two forms with different syntax and with different capabilities.

You're able to reference the same object, the same channels, the same time or frames, yet one understands world position and the other doesn't. What's the point of a limited syntax form and keeping it around? For that matter, why is it important to have caps correct or to spell out "position" or "rotation" all the way? What's wrong with Pos or Rot or just P or R?

I finally got my rig to do what I've been wanting for a long time, but there were no tutorials explaining how to reference world positions. I figured it out on my own from reading something in these forums and extrapolating, but I'm no where near to understanding LW's expressions like I did messiah's. Simple constraints and simple effectors aren't worth the effort to mess with as far as I can see. There's no blending between parenting, and the same goes for parenter.

This is an important character animation feature and it's lost to the average user.

06-08-2003, 10:24 AM
becuase Chuck

actually, thats correct.

prior to 6.5 expression syntax was all done thru a plugin and used this


when 6.5 came out, it integrated teh engine into the GE tab, and also allowed it to connect to bones, object layers, and such easier, hence why it is now

[object:layer.bone.rot.H] or whatever it is now.

I have forgotten a lot of the syntax since I am using Maya more fo animation now.

and that is object.ry for its syntax and when I am in LW, I use Relativity since it can easily access parent info for expressions as well as post IK info.

oh, to access world data try object.wpos(Time).H

06-08-2003, 10:44 AM
Got "object.wpos(Time).H"

That's what kept me from quitting and starting a florist shop.

Thanks for the info. I knew I could count on you, TW. :)

Maybe I need the new Ablan book for the expressions tutorial? (even though the Bastard promised me a free copy of another of his books because I plugged it but never got it...)

Maybe I should post the Dick VanDyke/Ablan - two dicks picture?

06-09-2003, 12:16 AM
I find it very confusing too. So I only ever use unbracketed. I also try to keep all the expressions in the motions panel, rather than the GE. This makes it easier to find the expressions when dissecting the scene.

If I have to use the GE (Texture or Morph expressions) then I use the modifier expression rather than expressions tab. That way I still have the ABCD scratch pad.

It's certainly a bit all over the place at the moment...

06-09-2003, 11:07 AM
You're right, and that makes a lot of sense, too. I find myself using the expression builder in the GE, because I don't quite know all the syntax or commands, though.

Oh well, learning... learning... learning... pop! there goes a cerebral artery. sigh...

06-09-2003, 11:30 AM
U can easy combine two syntax's ...
As the manual say Object.rot(Time).h is the L script syntax and [Object.Rotation.H] is new expression syntax ...
I newer use expression modifier from motions panel after some unsuccessfully case then LW was forget for each channel actually expression was made :hmm:

CGTalk Moderation
01-15-2006, 08:00 AM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.