prism docs · Designing · Shapes

Shapes

Every surface you project onto is a shape: a quad, a triangle, a circle, a polygon or a line. Add one and it appears at once, ready to drag onto the real object. Then pull its corners onto the object's corners, and soften its edges if you like.

WhereDesign ▸ Add, or the keys Q T O P L

Five kindsQuad, Triangle, Circle, Polygon, Line

Starts withthe Test Grid look (a line: plain white)

ModeSimple quads, triangles, circles, polygons, Feather
Advanced lines, Erode, curves

1 · Pick the right kind 2 · Add a shape 3 · Corners and points 4 · Circles, rings and arcs 5 · Lines 6 · Soft edges: Feather and Erode 7 · More shape settings 8 · Hints and tips 9 · When something looks wrong 10 · Mouse and keyboard

1Pick the right kind

A quad, a triangle, a circle, a polygon and a line on the canvas — The five kinds as they arrive: areas show the Test Grid with their number and name, a line is plain white.

Kind	Good for	Points
Quad `Q`	Anything with four corners: walls, doors, screens, posters, the faces of a box. Its picture stays in perspective between the corners, so a grid on a tilted door still looks like a grid on the door.	4 corners
Triangle `T`	Gables, pennants, the sides of a pyramid.	3 corners
Circle `O`	Round things (clocks, drums, portholes), ovals, rings and arcs.	4 corners of its frame
Polygon `P`	Any other flat outline: an L-shaped wall, a hexagon, the side of a staircase. Its picture is laid flat across its box.	3 to 32
Line `L` Advanced	Strips of light: outlines, neon tubes, the edge of a shelf.	2 to 64, with a width

Other ways to make a shape. Draw one freehand or with the Pen (Draw and Pen), map a whole box at once (3D objects), or let a phone scan find the surfaces for you (Pair your phone and scan).

2Add a shape

In Design, press Add in the canvas tool bar (or + at the top of the Surfaces list) and choose a kind. Quicker: press its key, Q, T, O, P or L.
The shape appears in the middle of the projector's picture, already selected, with the Test Grid on it so you can see it on the real object. If a shape is already there, the new one lands a little down and to the right.
Drag it onto the real object, then pull its corners onto the object's corners (next section).
Give it a look in the inspector on the right. See Choosing looks.

The Add menu in Advanced mode — The Add menu in Advanced: the five kinds with their keys, Mask, 3D object, Group from selection, Draw and Pen.

The Add menu in Simple mode — In Simple mode the menu is shorter: no Line, Pen or Group. Their keys still work.

Right-click ▸ Add shape puts the new shape where you right-clicked.
A new shape joins the group of the selected surface and sits right above it in the list.
No test grid? With nothing selected, the inspector's Start with the test grid switch decides whether new shapes start with the Test Grid or dark. It is a setting of this computer, not of the project.

3Corners and points

A selected shape shows a round handle on each corner or point. Drag a handle to reshape; drag inside the shape to move it.

A quad with its right-hand corners pulled in, in perspective — A quad's corners pulled in: the Test Grid follows in perspective, as it would on a door seen at an angle.

A polygon with a new point added on an edge — Double-click a polygon's edge to add a point there (the lime dot). It has the focus, so the arrow keys nudge it.

To…	Do this
Move a corner or point	Drag its handle. `Shift` keeps the move straight.
Nudge it	Press its handle, then the arrow keys: 1 px, or 10 px with `Shift`.
Add a point	Polygons and lines: double-click an edge, or right-click the edge ▸ Add point here.
Delete a point	Press its handle, then `Delete`; or right-click it ▸ Delete point.
Move the whole shape	Drag inside it, or use the arrow keys when no point has the focus.

The right-click menu of a polygon's point — Right-click a point: Delete point, Smooth point, Corner point, and the shape's own menu at the bottom. Curves are explained in Draw and Pen.

Quads, triangles and circles keep their corners. Deleting one of their points shows “A quad keeps its four corners. Press Esc, then Delete to remove the surface.” Esc takes the focus off the point and keeps the shape selected, so the next Delete removes the whole shape.

4Circles, rings and arcs

A circle sits inside a square frame with a handle on each corner. Drag a corner to stretch it into an oval; hold Shift to keep it round. The inspector calls it Circle while it is round and Ellipse when stretched.

A circle made into a ring with a quarter missing — A ring with a 55 % hole, drawn from 0° to 270°. The dashed square is its frame.

The Circle settings: Ring, Only an arc, From and To — Inspector ▸ **Circle**: Ring, Only an arc, and its From and To angles.

Ring cuts a hole in the middle, from full up to a 95 % hole.
Only an arc keeps a slice. From and To are angles that go clockwise from the right-hand side (0° points right, 90° down).

5Lines Advanced

A line is a stroke of light that runs through its points. Add points by double-clicking it; drag the small diamond beside its middle to make it thicker or thinner.

A zig-zag line selected, with its points and width diamond — A line of five points. The diamond near the middle sets its width.

The Line settings: Width, Closed loop, Ends and Corners — Inspector ▸ **Line**: Width, Closed loop, Ends and Corners.

Closed loop joins the last point back to the first.
Ends: Flat, Round or Square. Corners: Sharp, Round or Bevel.
With the diamond focused, the arrow keys change the width by 1 px (10 with Shift).

Neon outlines in one click. Right-click a shape ▸ Outline with light adds a closed white line that follows its outline, right above it in the list. Change its width and look like any line.

6Soft edges: Feather and Erode

Real edges are rarely perfect. Softening a surface's edge hides a pixel or two of misalignment and makes the light blend into the room.

Select the surface.
In the inspector, drag Feather. The edge fades out over that many projector pixels, inwards (up to 10).
Advanced Drag Erode to shrink the surface inwards (up to 5 px), when light spills past the object's edge.

The Feather and Erode sliders in the inspector — Feather and Erode sit in the inspector, under the blend settings. In Simple mode, Erode is behind the inspector's More….

A solid surface's edge with no feather, zoomed in — Feather 0 px: a hard edge (zoomed in).

The same edge with a 10 pixel feather — Feather 10 px: the edge fades out inwards.

Also while aligning. Advanced Right-click a surface ▸ Align on the object… has the same Feather and Erode under Edges. Masks have their own Soft edge (Masks).

7More shape settings

Lower down, the inspector has the shape's own section, headed with its kind (Quad, Circle…).

Make it a mask turns the shape into a mask that cuts what is below it. See Masks.
Curves Advanced: Smooth all corners and Straighten all edges. See Draw and Pen.
Mesh warp Advanced, for quads and circles: bend the picture over a curved object. See Mesh warping.

In Simple mode, Curves, Mesh warp and a line's settings are behind the More… at the bottom of the inspector. When a surface uses something Simple hides, such as a mesh warp, a small Advanced chip under its name says so; click it to show that section.

8Hints and tips

Use a quad for anything with four corners, even if it looks like a trapezoid from the projector. Its picture stays in perspective; a polygon's doesn't.
Zoom in for corners. Select the shape, press Shift + 2, and place corners with the projector window open. Finish with the arrow keys.
Shapes can share an edge. Two surfaces that meet along an edge leave no dark gap between them, so a wall can be several shapes.
Copy a finished shape with Ctrl + D: the copy lands slightly offset, right above the original.
Name as you go (F2 in the list): “Door” is easier to find than “Quad 7”.
A few pixels of feather hide a wobbly real edge better than endless corner nudging.

9When something looks wrong

You see	Why	Fix
“A quad keeps its four corners.”	Quads, triangles and circles have a fixed number of corners.	To delete the shape: `Esc`, then `Delete`. For more points, use a polygon.
Double-clicking an edge adds nothing	Only polygons and lines take extra points, up to 32 and 64.	Use a polygon, or remove a point first.
The picture looks warped on a four-sided polygon	A polygon lays its picture flat across its box.	Use a quad: its picture follows the corners in perspective.
The new shape isn't where I'm looking	New shapes go to the middle of the projector's picture, even when you have zoomed in elsewhere.	It's selected: press `Shift` + `2` to zoom to it, or right-click ▸ Add shape where you want it.
The new shape is dark	Start with the test grid is off on this computer.	Pick a look for it, or turn the switch back on (nothing selected).
Light spills past the object's edge	The shape is a little too big, or the projector's pixels are soft.	Pull the corner in with the arrow keys, or set Erode to 1–3 px.
No Line or Pen in the Add menu	Simple mode keeps the menu short.	Press `L` (the key still works), or switch to Advanced in the top bar.

10Mouse and keyboard

Action	How
Add a shape	`Q` quad · `T` triangle · `O` circle · `P` polygon · `L` line
Reshape	Drag a handle · `Shift` keeps it straight (a circle round)
Add · delete a point	Double-click an edge · press the point, then `Delete`
Nudge	Arrows 1 px · `Shift` + arrows 10 px
Duplicate	`Ctrl` + `D`
Delete the shape	`Delete` (with no point focused; `Esc` first if one is)
Menus	Right-click a point, an edge or the shape

Shapes

1Pick the right kind

2Add a shape

3Corners and points

4Circles, rings and arcs

5Lines Advanced

6Soft edges: Feather and Erode

7More shape settings

8Hints and tips

9When something looks wrong

10Mouse and keyboard

Related