View Full Version : CenterGravity LScript..what's a fair price?

Mike Pauza
10-04-2004, 01:38 PM
Hi guys!

CenterGravity.ls correctly places an object's pivot at it's center of gravity (CG), while LightWave usually doesn't. All objects naturally pivot about their CG, so positioning the pivot point correctly is essential for believable animation.

Here's some example screengrabs(LWCenter in BG - CenterGravity in FG), and a faq sheet.


This is my "first real LScript" and I want to sell it...and a bunch more down the road. I know, I know, I know, people don't want to pay for scripts but I can't afford spending time creating them and not make something. Just trying to support my newly aquired LScript habit. :)

So if you would, please give me some opinions what this thing is worth and what kind of demand to expect. Thanks for your help.

-Mike Pauza

10-04-2004, 06:13 PM
I'm not too sure many people would use something like this. Even when someone did want the correct center of gravity they'd probably just guess it, but that's just what I think, and I don't animate much :p

It does look like a cool script though. I'd suggest moving the pivot using setpivot(vector) than to actually move the object.

Mike Pauza
10-04-2004, 08:27 PM
Thanks for replying.

I bet a lot of people feel the same way you do, but testing out the script on a bunch of models from the content cd shows that some people can intuitively nail the center of gravity pretty well, but most have some difficulty.

A lot of the time I'm wondering how it will center, then see it and say oh yeah,
that's much better. :)

Thanks. -Mike

Anybody else?

10-05-2004, 09:52 AM
oops. should have read the rtf first.

Mike Pauza
10-05-2004, 10:11 AM
For anyone following this thread...a couple of folks over at cgtalk suggested a good price for a "handy LScript" would be about $5, but to sell it in decent quantities I would probably need to sell a handful of them together.

That kinda makes sense. That's for the input guys!


10-05-2004, 10:14 AM
I would agree.

10-05-2004, 10:20 AM
Hi Mike,
You might want to have a free demo version.
A simple version for $5.
And a Pro version with bells & whistles for $15.

Hobbyists would drop $5 without thinking -- if they liked the demo.
Pros would probably do a lot more, but it would have to have the extra pro features.

That's my 2c. :)

10-05-2004, 10:45 AM
Yep, I agree that you should put it into a pack with several other small tools, then sell the pack for $15-20, the price depends on what your other tools are though.

A demo is a great idea, but I'm not sure how you could make a demo of the center of gravity plugin. A video to demonstrate on a few objects would be a better idea I'd think.

Mike Pauza
10-05-2004, 11:14 AM

I like the demo/lite version and pro version ideas. Thanks.


It will be a while, but I'll come out with a pack of tools and have a video showing them in action.

Castius: Thanks.


10-05-2004, 12:32 PM
I was thinking of a time or use-count limited lite-version demo.
The video idea is great. That always stirs up interest.

If the demo proved useful, hobbyists would easily pop for the $5.
The pro-version should have some of the animation features talked about.
Then $15-20 would easily be reasonable. Maybe more - who knows - depends on what animators can do with it. ;)

10-11-2004, 04:03 PM
first, is it the center of gravity of the volume, or of the points. The problem with points is that a hand is very loaded with points so it would appear very heavy,,,where the body of an object would be the true heavy spot, but wouldn't appear that way with the model. you may want to use a wt map to say how heavy certain points are.

another option is to have it scan the model and then make a poly-line character. Then this could have the true weight built into it. Just have this object be effected by the bones or whatever they are displacing with. then have the calculations for center of mass based on this object.

if it is volume, you could sell it for about $5-10
if it is points, I think it would be better to sell it with a group of plugs/lscripts. make sure you have a nice functional lscript to sell something (and then give away something with it), or you may piss people off when they use it in the extreem casses.

hope this helps (don't mean to be negative...just trying to help you out... so please don't let this discourage you )

Good Luck,

Chris Reid

Mike Pauza
10-12-2004, 07:41 AM

The script calculates center of volume...using points, but not the objects points!!!

It uses an old numerical methods technique:
Basically what it does is create a bunch of one point polys with random positioning inside the the selected objects bounding box...a boolean intersect command leaves only the points that lie inside the original object. By "averaging" the remaining point locations you get center of volume...you could also calculate volume, rotational inertia, etc.

Thanks for the response Meta_Nerd!


10-12-2004, 11:31 AM
Excellent work.
I would assume its a modeler lscript? I was thinking it was a layout script, that constantly calculated the center of mass. I did a layout one along time ago for some of my character animations, thats why I wanted to make sure that you were thinking about it right.

Glad to hear that it works like that.

Definately $5-$10.

Mike Pauza
10-12-2004, 11:34 AM
$5-$10? Thanks.

A layout center of volume is a good idea. I've been toying with writing a center of gravity script for bones. Is that what you did?


10-12-2004, 02:18 PM
no I actually wrote it as a messiah plugin, mainly because That is what I used to animate my characters at the time, and it is very fast.

The thing I never did was make it show the Inertia of my object/or object parts. I always said I was going to go back and do this....but you know how that goes.

I didn't write it for sale, it was just a personal test to try to learn how to write plugins. Feel free to use any Ideas I have shared. I would love to see it work. If you get it working as an lscript, maybe we could convert it to a plugin (that just makes it quite a bit faster).

Good luck