Projection Alignment

Alignment for any kind of projection surface can either be done manually or by using auto-align tools. The process of alignment produces geometric data that warps the regular media to project correctly. Geometrically simple setups with smaller numbers of projectors do not require auto-alignment systems to achieve this warp data, but with large numbers of projectors, dome theatres and projection mapping, this becomes a very time-consuming task, that will only require repeating with any theatre adjustment, including lamp changes.

In both cases, geometrically accurate patterns are projected onto the display surface and observed, either by eye or camera. The warp data for each channel (projector) is held in Delta Geometry resources and applied to the background / display layer (i.e. to apply to the whole canvas and all visual media resources. Adjustments are made until the projected geometric patterns are correctly aligned. In the case of auto-alignment tools, the process may also include auto-blending and colour correcting overlapped media regions.

The geometry file can be saved separately as an .xdl file and then merged with any show on this display.

General notes for manual alignment of flat or curved screens

•The media design must match the aspect ratio of the display surface, not the additive dimensions of all channels, which overlap by around 20 per cent.

•Using a laser line will help provide a true horizontal and true vertical visual reference .

•The grid pattern projected consists of true squares. Physical measurement of diagonals will confirm aspect ratio.

•Work progressively with two adjacent channels, left to right.

•Adjust channels towards each other, not all one towards the next.

•Get everything almost right first, then go back and improve.

•With each channel, start with simple geometry (the four corners) before adding grid points to finesse your warp.

Guides

➢Flat-screen manual alignment setup and process

➢Dome Mode auto-alignment using Scalable Display Technologies Display Manager™

➢Projection mapping (Mesh Mode) using .obj geometry definition files and Delta 3D calibration

Page edited [d/m/y]: 16/12/2020