Modifiers on a mesh — ModelCraft help

A modifier changes what a mesh shows without changing the mesh itself. Mirror one half of a part and model only that half; round a box with a subdivision surface and keep editing the box. Modifiers sit in a stack and work in order, top to bottom. What you see, export, print and render is the mesh with every modifier that is on.

Add a modifier

Select a mesh. In the Model workspace its Modifiers section is in Entity info; in the Mesh workspace it is in the panel on the right.
Pick one from Add a modifier…. It goes to the bottom of the stack.
Change its settings below its name. Lengths take the same values as the Value box, so 600mm, 2'6" and (6m)/4 all work.

Every change is one undo step: ⌘ZCtrl+Z takes it back.

The buttons on each modifier

The checkbox turns it on or off.
The screen button shows or hides it in the view (it stays in the stack).
The camera button shows or hides it in rendered pictures and videos, so a modifier can be for renders only (or for the view only).
The arrows move it up or down the stack. Order matters: mirror then subdivide gives a smooth seam, subdivide then mirror does not.
Apply makes the shape part of the mesh: the modifiers above it and this one are done to the mesh itself and leave the stack. It is one undo step.
The cross removes it.

The modifiers

Modifier	What it does
Mirror	Adds a mirrored copy across red, green or blue through the mesh's origin, and joins the halves where they meet.
Array	Copies in a line (a step of its own size times the numbers you give, plus a fixed step), round an axis, or along a curve in the model.
Subdivision surface	Smooths the mesh by Catmull-Clark subdivision. Sharp edges stay creased. Renders can use more levels than the view.
Bevel	Rounds every edge sharper than the angle you give.
Solidify	Gives a surface a thickness and closes the rim.
Boolean	Cuts away, joins or keeps the overlap with another object in the model. Both need to be closed solids.
Displace	Moves the surface in or out by smooth noise. The same seed gives the same bumps every time.
Weld	Joins vertices closer than a distance.
Decimate	Keeps a share of the triangles, removing the ones that change the shape least.
Smooth	Relaxes the vertices toward their neighbours.
Lattice	Bends the mesh with a cage: move the cage's points and the mesh follows.
Curve deform	Bends the mesh along a curve in the model, along red, green or blue.
Shrinkwrap	Moves every vertex onto the nearest point of another object.

Subdivision surface

Subdivision smooths a mesh by Catmull-Clark: every face becomes four-sided faces, and each level makes four times as many. A box with two or three levels already reads as a rounded shape, and you keep editing the box.

Levels in the view sets how smooth it is.
Levels in renders sets how smooth rendered pictures and videos are; renders can use more levels than the view.
Renders on the true smooth surface puts a rendered mesh's points on the limit surface the levels tend to, so even two levels render as smooth as many.
Creases keep edges sharp: in the Mesh workspace select edges and use Crease (1 stays sharp, 0.5 rounds a little, 0 is smooth). See Edit a mesh.
Lower the view level on a big mesh: when the levels you ask for would give more faces than this computer's view handles well, the view shows a lower level and says which. Apply always uses every level. How many faces is set by your machine's class in Settings › Rendering › Your machine.
Open borders keep their corners and stay on their edges' line.

Bend with a lattice cage

Add a Lattice modifier and press Add a lattice cage round the mesh. A cage of 3 × 3 × 3 points appears round the mesh, drawn as wires.
Open the cage in the Mesh workspace (double-click it) and move its points. The mesh follows smoothly.

Big meshes

Small stacks are worked out at once. A big one is worked out in the background on every core of your computer: the view keeps showing the last result until the new one is ready. Booleans load the solid modeler the first time; the view says so for a moment.

What modifiers do not do yet

Weights per vertex (a falloff painted on the mesh) for Displace, Smooth and Shrinkwrap.
Modifiers on push/pull geometry: turn it into a mesh first (Convert to mesh).