Attached Link: http://www.kuroyumes-developmentzone.com/appleyard/temp/_movie_00_ns_nb_avi.zip

This link points to a zip file which contains a movie (at screen-display quality) and the .PZ3 file that I used to make the movie. This still is a render of frame 21 of the movie. In the movie he draws and aims and fires the raygun. The gun is parented to his chest. Both his arms are IK-on. His hands are IK-parented to the gun so that his arms follow the gun. It needs my workman and ray gun and cop-belt models.

In the movie, his left arm starts out OK, but between frame 26 and frame 27 his left shoulder and forearm flip into a wrong pose. This is as a result of Poser starting to take the wrong solution in its solid-trigonometry when (converting the hand's x/y/zRotates from (relative to the gun) to (relative to the forearm)) and (adjusting the shoulder's and forearm's x/y/zRotates to match with the fixed position of the hand). Setting joint limits won't work, as the limits apply to the values BEFORE all this adjustment and messing about. I have tried this and that. (In a longer movie that I made where he puts his gun back on his belt afterwards, his left shoulder and forearm flip back to the correct pose as his left arm moves gradually back to the "at attention" pose.) Has this bug been cured in Poser 5? It seems that when rendering a movie, (converting the hand's x/y/zRotates from (relative to the gun) to (relative to the forearm)) and (adjusting the shoulder's and forearm's x/y/zRotates to match with the fixed position of the hand) should choose the solution as near as possible to the solution used when making the previous frame. I know that (solid-trigonometry equations involving arcsin and arccos and arctan and suchlike) tend to show multiple solutions.

Message edited on: 06/01/2004 11:45

The arm looks a bit too straight by the end of the movement, maybe bending it a bit might help with the animation?

His left elbow must be nearly straight to reach the gun's front grip when the gun is in firing position.

Yes, but a slight bend at the elbow might help with the animation.

I'm not sure I can help, but I wanted to say that thatis a rather ingenious workaround you've got there, parenting the gun to his chest, and the hands onto the gu... I'll have to try it with a sword....

Ok, having looked at the film, I have a suggestion: The final pose that you have him in is unnatural. The gun shouldn't end up exactly perpendicular to his shoulder line. There are several ways you can fix this, the easiest of which would be to twist his chest so that HIS right shoulder goes back a bit and his left shoulder comes foreward. that should eliminate the need to overextend his left arm, making the elbow lock up like that. you've definitely got to twist the chest, at the very least.(of course, twisting the chest is going to mean repositioning the final keyframe for the gun, so that it still points where you want it.) For something a bit more dramatic, instead of twisting the chest, twist the hip, spread the legs a bit, drag the right foot back, and lower the hip a bit to bend the knees. And make sure his head still points foreward... If you want, I'll tweak the file you uploaded, and send it back to you, so you'll see what I was talking about.

I would have the gun positioned a bit more to the left so that the left arm pose doesn`t have to be so unnatural. The whole figure could then be turned to point the gun in the right direction.

but it's not just the left arm that looks unnatural. Stand up and try the pose yourself. Nobody's going to stand like that and hold a gun straight out from the center of their chest. Especially not if the gun has any kick, or they'll most likely break their solar plexus, for starters.... The angle between the gun and shoulder line should be about 45 degrees at most. The back end of the gun sould in this case point at his right bicep, and when it kicks, it should slide past the chest on the right side. My most basic advice on planning an animation: Get up out of your chair, and do the action yourself. Several times. Try to put thought and emotion into it. Use a stopwatch to time yourself.

Message edited on: 06/02/2004 22:09

Thanks.
I should point out that the gun is a ray gun and does not have recoil like a projectile-firing gun.
This gun is in the freestuff :: I made the model.

Message edited on: 06/03/2004 00:47

In my experiance anytime you animate a limb with IK and have the joint nearly straight you wind up with a problem in the software determining wich way to bend the joint. Is it an option to scale the gun slightly smaller ? Keeping the elbow slightly bent may help your problem. Another way is to add keyframes where the problem occurs to 'help' the software pick the solution you want.