# Lattice morphing with shapekeys?

Hi.
I have a box mesh morphing in to a U shape with a shape key.

Is it possible to have a lattice cage that also deforms with my mesh? Meaning the lattice starts as a bounding box to the box and when the shape key finishes the shape key cage its a perfect boundary of U shape ?

Thank you

I might be wrong but I think not, you can do it the other way around, use a shape key for the lattice and deform the cube with it.

1 Like

Yes I was thinking that and actually it sounds it will be more efficient.

I actually started doing that by snapping the cage of the lattice to the actual geo from the arched mesh.

1. Make a box
2. Make lattice with the amount of divisions needed to snap to the arched mesh
3. Added the modifier lattice to the box and start snapping the vertex of the lattice to the arched mesh.
4. The deformation does not happen exactly as If I was snapping the box vertexes to the other mesh…it seems like the lattice have an area of influence (The lattice is exactly at the bounding box of my box mesh).

Do you know how to fix this?

Just to be sure I understand correctly.
Your proposal:

Apply a lattice box to my shape key (morph between box and arch) ?
How the lattice will adapt to arch when the mesh morphs into an arch?

I tried to follow your instructions.
My main goal to make the lattice to follow the shape of my shapekey mesh.
Unfortunately If I do my shapekeyed mesh morphing from a box to an arch the lattice will deform the arch if I move it.

Actually there is an easy fix to get them exact, the interpolation of the lattice properties controls the fall off influence. Set interpolation to linear:

Edit
What I have done is:
create cube and subdivide
create lattice the same size and subdivisions
set interpolation of the lattice to linea
Make a shape key for the lattice and curve the lattice in edit mode of the shape key.
Put a lattice modifier on the cube.
Now using the shape key influence of the lattice will deform the cube in the same way (without fall off influence)
Edit2

The goal of a lattice is to deform a mesh so yes if you move, rotate scale or deform it will change the mesh
Edit 3 !!!
Here is a file that I think might be what you are after. What I have done is the same as above then at the end I made a linked copy of the lattice (so now there are 2) you can now move the second lattice around and it will still work.
Lattice.blend (907.1 KB)
Here is the file if you press play you can see the result.

Edit 4 !!**!!!
I made a quick video

Thank you so much for your time ! I really appreciate your help. I will take a look during the day and get back to you Thank you a lot really

Thank you so much! It looks like this is what I need

I am still not sure what is the linked lattice for, but if it works it works.
What I needed is to have a box shaping into a specific arch. I could do it with a shape keys without lattice, but they want a landscape on the top surface from the box and arch…and then someone decided to add a lattice to do that.

What your solution now I can skip the shape key of the mesh and just use the lattice to do that.

I am still curious about the use of the lattice linked ?

I made the linked lattice because I thought that you wanted to use the cubes deformation to drive a separate lattice that you can move, rotate and scale without affecting the cube, while still using the cubes deformation.

The second lattice could be used to deform a different mesh (another cube, sphere or anything) and you could move it around, scale it or rotate it without affecting the cube and its deformation.

The lattice has the interpolation modes because usually the geometry of the object you are deforming does not coincide with that of the lattice, it works a bit like bone weight and needs to pull vertices that are not in line with the lattice vertices.
If the cube had a lot more geometry than the lattice the BSpline option would give you a smooth curve, the linear option will give flat faces on the lattice edges and the object would look low poly (even if you subdivide it).

If I understand correctly you need to use the lattice deformation to deform a “landscape” on top of the cube. I am not sure if the linear interpolation will be good for this as the landscape geometry will not be cubic.