Layer Pivot point does not follow translation

General Moho topics.

Moderators: Víctor Paredes, Belgarath, slowtiger

Post Reply
NicoGZ
Posts: 19
Joined: Wed Oct 07, 2015 12:37 am

Layer Pivot point does not follow translation

Post by NicoGZ »

Hello everybody. I have a character rigged without problems. But for one particular scene, I added skating protectors to his elbows and knees. I flexibinded the elbow protector to the forearm bone, and set the Pivot point so it rotates better when the arm bends, and also adjust the layer's position so it looks better at the end of the smart action. To my surprise, when I go back from the final frame of the action to see how it worked, the elbow protector does a little "jump" of position and lands in another place, a little off from where I told it to be. I return to the final frame and, alas, it is also changed a couple of centimeters (depending on zoiom of course). So I put it again in it's place, but jumps again when i change frame. I noticed that this happens because the pivot point does not translate along with the object.

Picture the usual box that surrounds the layer when you choose "transform layer", with the pivot in it's center or wherever you put it. What happens is that when I move it, instead of moving along, the box just gets bigger, to complete the rectangle between the pivot and the object, with the pivot staying in the same exact X/Y coordinates of frame 0. So all the movement gets distorted and I cannot control where the layer is when I move it.

Has this happened to anyone else?

Thanks
User avatar
Greenlaw
Posts: 9192
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Layer Pivot point does not follow translation

Post by Greenlaw »

The pivot point (or 'origin' in Moho terminology) moves with the layer not a bone, and it's not an animateable properly so moving it probably shouldn't cause a 'jump'. Without seeing any examples (screencaps, videos or files,) my guess is that something else may be causing the 'jump'. Here are a few ideas:

The layers and points can be animated independently of bones, so are you sure there are no keyframes on the group or individual layers causing the 'jump'?

Are you using any Actions on the bones? It sounds like the 'jump' may be occurring because of a mismatch in the Action.

For example, when I create an Action, I normally place a keyframe at frame 1 and set it to linear so the action doesn't get affected by the interpolation mode used at frame 0 on the Mainline. However, sometimes I may accidentally have a different transform at frame 1 in the Action than at frame 0 on the Mainline, which can cause a 'pop' when the Action becomes active. After I make sure the Action's frame 1 matches frame 0, the 'pop' goes away.

I don't know if that's what's happening in your scene but maybe something similar?

A slight mismatch in a loop can cause that too.

It would help if you showed an example.
Last edited by Greenlaw on Wed Nov 15, 2017 8:31 pm, edited 1 time in total.
NicoGZ
Posts: 19
Joined: Wed Oct 07, 2015 12:37 am

Re: Layer Pivot point does not follow translation

Post by NicoGZ »

Hi, thanks. Sadly I cant post any screenshot, my boss won't let me. But I think I am understanding what happened:

The Layer was linked to a particular bone. In the smart action of that bone, the bone moved from A to B and the layer followed. But if I tried to move the layer WHILE it was also being moved by the bone's movement, it got confused and jumped off it's place, i think to match what the program though was the proper "follow bone" coordinates.

There wasnt ant additional animation in any of the layers involved. Finally, I linked the layer to another bone, the arm bone, and told it to move and rotate to fit the arm's shape when the forearm bone moved. As it's linked bone, the arm, does not move in the forearm's action, I could freely translate the layer as I wanted without causing conflict.

I don't know if I am explaining myself properly. But that was a way of solving the problem, without knowing exactly what was wrong.

Thanks!
User avatar
Greenlaw
Posts: 9192
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Layer Pivot point does not follow translation

Post by Greenlaw »

No worries. I'm not allowed to show stuff I work on either, so understandable. :wink:

Glad you got it solved.
Post Reply