Projection Mapping Workflow

This guide takes a multi-projector wall from an empty rig to a running show: plan, connect, set up the Stage, correct the projection (with a VIOSO calibration or with Exaplay's own Projection Setup), map the content and check it. Each step links to the page that explains it in full.

Walkthroughs

Two recorded walkthroughs follow this workflow on the real Stage:

• ☰ menu → Walkthroughs → Outputs & projection → Assigning outputs to screens
• ☰ menu → Walkthroughs → Outputs & projection → Two projectors, one picture

Step 1 — Plan the projector layout

Before installing, work out:

• Projector positions, throw distances, lens shift.
• The overlap between neighbouring projectors — typically 15–25 % of the image width. The overlap is where the edge blend happens.
• The content resolution of the wall: e.g. three 1920 px projectors with two 288 px overlaps give 3 × 1920 − 2 × 288 = 5184 px.
• Which machine drives which projector, on a multi-machine rig.

Factor	Guidance
Overlap	15–25 % for a smooth blend; more overlap, softer seam
Lens shift	Prefer optical shift over digital keystone
Keystone	Get the projector as square as you can before correcting in software
Brightness	Same model and similar lamp age

Step 2 — Connect the projectors

1. Connect every projector and set it to its native resolution.
2. In Windows Display Settings, set the displays to Extend (not Duplicate) and arrange them in the order they hang.
3. On a multi-machine rig, set up the clients first — see Multi-Client Setup.

Step 3 — Build the screen on the Stage

1. Open the STAGE tab. Every screen sits there as a card with its fields.
2. The + after the last card adds a screen (with one field). Name it in the inspector — e.g. Wall.
3. If the content has a fixed size, type it into Content resolution in the screen's Canvas card; with both fields empty the screen takes the size of its outputs.
4. Add or size the fields the content will play in. One field over the whole screen is the usual start.

See Output Setup → Screens.

Step 4 — Assign the projectors

1. Open the screen: click the arrow under its card. Every PC of the rig — this machine and every client — appears under it, with its projectors as boxes above it.
2. Name the outputs so you can tell them apart — Proj L, Proj C, Proj R.
3. Drag each box up onto the screen card (or select it and pick the screen as its Assigned screen). An assigned box takes the screen's colour and a line connects it to the screen; an unassigned one is drawn hatched, and its projector stays dark.
4. Leave monitors that are not part of the show (the operator's GUI screen) unassigned.
5. Press Identify in the header: every projector shows its name on the wall. Check that the names match the positions; switch it off again.

See Output Setup → Assigning.

Step 5 — Lay out the overlap

Skip this step with a VIOSO calibration: the calibration places the channels.

For the Projection Setup, the overlap on the Stage is the blend width:

1. Select one of the screen's outputs and set its Alignment (under Assigned screen) to Rearrange (the default, As in Windows, follows Windows).
2. With the screen open on the Stage, drag the projector boxes edge to edge (a drag never overlaps them), then select one projector: its Overlap & Blend card lists the neighbour with edge to edge, Overlap 0 px. Type the planned overlap into that number and this projector moves over its neighbour. The number stays editable after the blend is switched on.

See Arranging the outputs.

Step 6a — With a VIOSO calibration

1. Calibrate the wall in VIOSO 7 (camera, dark room, projectors warmed up for at least 10 minutes). On a single PC use the project template Exaplay 3, which exports straight into Exaplay's calibration folder; across several PCs use Generic with a Destination Parameter, which exports one .vwf per PC — see VIOSO calibration.
2. Select the screen → Calibration → Load… and pick the file (of a per-PC set, any one — the others come along) — or drag the .vwf from the Stage's content browser onto the screen card. Do this on the master; the clients get the files with the show.
3. A calibration that fits says nothing: Status reads Applied. If the screen's size differs clearly from the calibration's, Use the calibration's size? shows both sizes side by side — click the calibration's to take it. If the channels do not land one per output, the assign tool opens: drag each channel onto its projector — on any PC of the rig — while the wall shows the VIOSO test image, so you see every projector take its channel.
4. Check which projector draws which channel: Identify in the Stage header labels each projector with its channel. If one shows the wrong slice, Needs assigning › (or Edit… beside Status) opens the calibration's dialog again.
5. While that dialog is open the wall shows the VIOSO test image through every channel's warp and blend, and each output's tile shows the same picture — so a mirrored or rotated mapping shows there at once.
6. Not sure whether the calibration or the picture is at fault? Raw wall in the Stage header shows this machine's outputs without any correction; press it again (or Raw wall ON in the top bar) to go back.

See VIOSO calibration.

Step 6b — Without a calibration: Projection Setup

1. Select the screen → Warping → Manual Warping → Open editor.
2. Warp: for each output, pull the four Corners onto the surface; refine the Grid to 3×3, 5×5 or 9×9 for a curved surface. Mode → Perspective (4 corners) keeps straight lines straight on a projector that is not square to the wall. A single bump: a pin (double-click the picture) instead of a finer grid.
3. Edge blend: switch Enabled on with Auto widths from overlap — the width is the overlap of step 5, shown on the card under Overlap on the Stage (Right · with Beamer R 240 px). (Or use the Edge blend switch in an output's Overlap & Blend card: it switches the blend on for both outputs of the seam.)
4. On the wall: set Pattern to Vernier (overlap check, ×20). If the fringe is not on the centre mark, the overlap on the Stage is not the real one: type the overlap you read into the Overlap on the Stage number on the Edge blend card (the same dial sits in the output's Overlap & Blend card) or nudge it with ↑ / ↓ until the fringe sits on the mark. Then Grey 50 % (seam test) — the seam should vanish; adjust Curve and Gamma.
5. Black level: raise Lift until the area one projector lights alone matches the overlap in a dark picture (Grey steps).
6. Set Pattern back to Show content and close the editor.

See Projection Setup.

Step 7 — Map the content

1. Render content at the screen's content resolution (step 1), or let the screen's Content scaling fit it (Content on this screen: Fit, Fill (crop), Stretch, Keep resolution).
2. In Produce & Play, point a track or composition at the screen with its Plays on property, and play.
3. Press Outlines in the Stage header to see where every screen and field lands on the real wall; switch on Preview to see the live picture on the Stage.

See Additional fields.

Step 8 — Final checks

Check	How
Every projector shows the right slice	Identify on the wall; Status Applied in the screen's Calibration
Geometry	Grid + circles pattern in the Projection Setup, or Edit… in the screen's Calibration (the VIOSO test image on the wall); from your desk, the Output view of the Output Preview
Blend	Grey 50 % (seam test) — no visible seam
Black level	Grey steps — the dark stripe is even across the overlap
Colour	A mid-grey picture — all projectors match
On-wall aids off	Identify, Outlines, every test pattern and Raw wall switched off (no Raw wall ON in the top bar)
Saved	Save the project — the calibration, the Projection Setup and the output settings are stored with it
Going on air	SHOW ON in the header; Blank fades every output to black and back

If something is wrong, see Outputs Troubleshooting.