Good heavens, ronstuff, thank you for taking my post in such a good spirit. If more people could discuss their pet ideas with such open-mindedness and courtesy, 'rosity would be a much happier place.

And thank you for bringing the subject up again. Before, I was just content with understanding why gimbal lock happened within the Poser system. Your post forced me to ask the (come to think of it, obvious) question, "Why does Poser use this system? Aren't there others?"

And that's still a good question. Trying some more refined Google searches linking those 3d software programs with "gimbal lock," I'm beginning to get the impression that a lot of them have found various ways of finessing gimbal lock problems that were more prominent in earlier versions. (Maybe Max is one of them.) So maybe there's hope for Poser.

And as far as the tradeoff -- the problem Poser avoids by living with gimbal lock -- so far I've only seen little hints of what that is. I'd love to know, and I'm sure you would too. I think we are most likely to find it by following up the medical biomechanics links; apparently the doctors who reconstruct shoulders and hips face a similar tradeoff when trying to model those joints.

I had a tooth extracted today, so I literally have a hole in my head and am probably not going to learn anything more about this tonight. I didn't mean to leave the false impression that I actually understand Euler angles or Quaternions from a math standpoint (or any other standpoint) -- I was just summarizing the articles I saw in Google. With your CAD and programming experience, you will probably get more out of those references than I do.

But if I do turn up anything on the nature of the tradeoff, I will post it here. And I'll be very interested in anything you learn about this as well.

Thanks again for making this a real dialogue and not battling rants.

Bill

No problem here either.

Sorry, it's not a flim-flam or a smokescreen, it's a well-known problem for any rotational matrix using orders of rotation and computing Euler angles. It's a straight kinematic problem and has nothing to with X-rotate being coded different from Y-rotate by CL.

You can find tons of documentation on this via Google. For instance:

http://www.edharriss.com/tutorials/tutorial_xsi_gimbal/xsi_gimbal.html

http://www.fho-emden.de/~hoffmann/gimbal09082002.pdf

http://wiki.beyondunreal.com/wiki/Brush_Rotate

http://art-design.smsu.edu/yarberry/Courses/Reference/PivotPoints/

http://www.darwin3d.com/gamedev/articles/col0398.pdf

Now, does Poser have to use Euler angle computation? No, here you're right, there are other ways to go that don't gimbal lock. But there may be good reasons why CL did not go with the alternative (Quaternions, also called Euler parameters -- different from Euler angles). There's a detailed discussion of exactly that subject here:
http://isb.ri.ccf.org/biomch-l/archives/biomch-l-2001-05/00018.html

And this link claims (I don't own any of this software, so I couldn't tell you one way or the other) that Poser is far from alone among 3D programs that use Euler and get gimbal locked. Says the same thing is true of Maya, Max, Lightwave, and Softimage:

http://www.anticz.com/eularqua.htm

Bottom line: there's some kind of tradeoff between gimbal lock on the one hand and problems interpreting anatomical biomechanics on the other. Since Poser is all about anatomical biomechanics, they chose to live with gimbal lock. A drafting program would go the other way.

It's not messed-up code, though, and assuming otherwise isn't going to get you anywhere.

Bill

And let me add that you should not let person B resell your omni as part of his product X. The fact that he sells X for more than you sell the omni does not repay you for your time or idea. You sell one copy to B for ten bucks, and he sells a hundred copies of it, adding ten bucks to the price of some cheap prop to house it? Not fair to you. Let him get a fair price for his prop, no more, no less. If you set a price low and fair enough, B can sell X as a housing for the omni at a low and fair price of his own, pointing his customers back at you.

Let me say that less confusingly. It's like you're selling a figure and you're happy that other people can make money selling textures for it -- but you don't let them include the figure with their texture. Why should you?

Bill

Aaah, it's a character, not just LT2 lights that parent to a control globe . . . I should have realized that's how you can have ERC . . .

You really are adding a lot of value to the idea. I feel sure there's a market for it. How much people would pay I don't know, but it's a great effect, even in my crude version (which does not seem to illuminate as brightly as yours despite having more lights.) People definitely want the effect, and when you add up the hours it would take to build their own, why wouldn't they want to pay ten bucks instead? Of course, in terms of how much time it would cost to make it yourself, if you value your time at minimum wage, you'd theoretically pay a lot more than ten bucks. The problem is, above ten bucks there are so many other products that one doesn't own yet and that would enhance one's Poser projects even more than an omni.

The biggest mistake people make in the Market is to price something at what it's "really worth" rather than what people will pay. A hundred sales at five bucks is better than ten at twenty bucks, and that's the kind of demand curve you run into here. Just one man's opinion.

Anyway, I can now answer your question. Under ten bucks, I'd buy.

Bill

I don't know, the last time someone explained "gimbal lock" (or at least, the last time I read about it) in the Forum, I thought they did a good job. If NASA can't solve it, I'm not sure CL can.

(That came out snottier than intended. I do admire the trouble you've gone to to make this problem concrete. Who knows, maybe you'll find a new angle on it.)

Bill

SnowSultan put a version of this in Freestuff a few weeks back, and I'm including my own variation in a product out shortly.

That said, it sounds like you've added some intelligent wrinkles to the idea that would make it worth a few bucks to anyone who didn't want to go through all the tedium of building his or her own.

The problem with having two omnis in a scene is not just crosstalk, of course, it's that the second omni must have a completely different set of light names or it will simply take the first omni's place as the scene's Lights; and if the second omni DOES have a completely different set of light names, the first omni will be blacked out when the second is introduced and every black bulb will have to have its luminosity turned back up, one by one.

If your ERC thing gets around that drawback, you're really adding value to the idea, and that's the way to get paid for it.

Good luck!

Bill

Uh, take a closer look jqesq: space_program asked the original question, then added that it was a Poser 4 question as a clarification. It wasn't some second person butting in and telling him "Sorry, this is a Poser 4 question." (Actually, I had the same reaction as you did when I read it the first time.)

I think VK deserves a round of applause for one of the simplest, shortest, yet clearest explanations of gimbal lock I've ever seen. Whenever I've tried to explain it to someone else, I get brain lock.

queri makes the essential point that it's excessively high-res textures that are more likely to choke your computer than Vicki2's mesh. My no-longer-cutting-edge machine doesn't balk at having several V2's in a scene, but just one with an overly hi-res texture will knock it down. The good thing is, one hardly ever needs that much res, and most textures don't shoot that high.

"I know you all, and will awhile uphold
The unyok'd humor of your idleness"
-- Henry IV, Part I, Act 1, Scene 2

Even hates Shakespeare.

Excellent! I've never had big problems with P5, and they seem to be knocking off the little ones one by one.

Pokeydots,
Does that mean MAT poses will work now? I think the transparency falloff was the only thing P5 didn't get about them.

Bill

Find and read tutorials. Find and read tutorials. Find and read tutorials. Auto update sounds like one of the UV Mapper Pro features you don't need; saying it's disabled reminds you that you can get more features from UV Mapper Pro (which costs money, is worth it, but is not necessary to do what you want to do.) Find and read tutorials. Find and read tutorials. Find and read tutorials.