deformation error (bug?)

[bwcc]

I'm hesitant to call this a bug, because it has done this for as long as EIAS has had deformations, maybe version 2.x, not sure. But I wanted to submit it to see if anything could be done.

When using multiple bend deformation regions along the length of a cylinder (or similar shape) some regions can be affected by the deformation of other regions. I set up a project with a cylinder and 4 equal regions. Each region bends at 90 degrees and should deform the cylinder into a torus. I know this shape could be made other ways with or without deformations, but this is a good example of the error that occurs.

I uploaded the file in the "Animator Bugs" called "def error.zip"

thanks,

brian

[Igors]

Hi, Brian, All

Not a bug, bend does not do this. It uses each vertex' position to calculate actual bend angle. The Region 1 (magenta in attached image), Along X-axis, therefore:

- if vertex X

- if vertex X > 50, then 90.0 (maximal) angle is applied

- if (0.0

With all top 3 regions everything goes fine - all right vertices are deformed with 90 degrees. But for Region 1 (bottom) the vertices of last segment appear inside X-range [0..50] again (as a result of previous deforms), so a fancy result happens.

Note also that, regardless this region issue, bend can't close circle to make a full torus (in this case): rotation does not change radius, so left and right vertices will not coincide.

Need to find a workaround, here artists can advice better than we

[bwcc]

I think I understand why it's doing this and I have thoroughly explored all the limitations and work arounds. I uploaded another file that is not a torus, it does not bend all the way back on itself but it still has vertices affected by multiple regions.

The stretch deformation has a "capture vertices" to ensure the region only affects the vertices in the region. Is there any way to get the bend regions to only affect the vertices inside the region? I know we can check the boxes next to the X region dimensions but that puts the vertices all the back to their original position. I want to able to add bend deformations along the length of a cylinder to create a specific shape. Sometimes the limitations of the deformations can make it impossible.

I understand this may not be classified as a bug, but could we make a feature request?

thanks,

brian

[RichardJoly]

Now check what's happening in this movie between 4 and 5 seconds...

The other half of the chair is deforming by itself. What's happening here?

You can even delete regions 6, 7 and 8 in the Project.

Movie:

http://www.rdnmultimedia.com/eias/Bending_Chair.mov

Project:

http://www.rdnmultimedia.com/eias/Bending_Chair.zip

[Igors]

Hi, Brian, All

I understand this may not be classified as a bug, but could we make a feature request?

Here we've no idea what this eventual feature should do.

"Capture vertices" (stretch) does not mark/save individual vertices. it just stores deform region (cube) in private data to have a blended stretch between saved and actual regions. For Bend it makes no sense.

Bend prob is what to do with vertices outside region. Apparently we need "left unchanged" and "right fully rotated" but how to detect where is left/right for complex models? We agreed the actual method isn't perfect but we see no a better one

[bwcc]

At least for me, the perfect solution would be to deform an object along a path drawn in EIAS. I currently have Northern Lights Contortionist, and seems to well with the limitations of a plugin.

The resolution or number of segments in the deforming curve is dependent on the animation fps, which makes it difficult to animate the object moving through the deformation. And, especially on big models it gets very slow. The plugin tessellates the deformed model to conform to the curve and the render times can be as much 10x. I almost always have to deform the model, then save it out and import, this is only good for stills, not animation, and the maps applied to the original model don't work.

This would clearly be a new (and totally awesome) feature.

thanks,

brian