Friday 24 December 2021

Accurate Projection Mapping

Accurate Projection Mapping..

There are 3 main ways to do accurate projection mapping.

The very expensive way - a LIDAR laser scan  of the building and a 3D based media server such as Disguise

The difficult way - drawing onto the building through the projector with an app like photoshop - usually means being outside all night

and then there is the way I do it..

Work from a photograph taken from the projector position.

I invented this approach myself back in the days when I used to do building projections with slides and needed to get it right first time every time. Sometime in the early 1990s if I remember rightly.

So here’s a brief walk though of the latest mapping project that I did for EMF onto a town hall in the UK

First, photograph the projection surface from the projector position

To get this photo, I had to put the camera on a light stand and wind it up to 20ft - the final position of the projector on a scaff tower in the square..

I then pop the photo into photoshop and make a template that acts as a map for all the content and I also use to generate a line up for the individual projectors. In this case using a 1920 x 1080 pixel template that matches the native resolution of the projector.

Then you just do all the content - I drop the .psd template into after effects and do everything there..

finally I generate a lineup - using the original photo + find edges, invert & levels. which is projected back onto the building to bring the projected image into a perfect fit for the actual building.. 

Of course there is bound to be a small amount of final adjustment but it’s usually just an inch or so off - all down to manufacturing tolerances in projector lenses, accuracy of projector placement and so on. I use Resolume Arena for playback. On this particular job the lower centre was off by around 4" so it just needed a tiny nudge in advanced output. If you can't afford Resolume, take a look at Qlab, which is free so long as you don't save, or you can rent it by the day.

here’s the end result..

projection 3 x 18k lumens Christie HD projectors
Playback Resolume Arena

Here's my original how to vid from 2007, ignore the bit about comparable lenses.. seems I was mistaken about that bit of the process..

Have fun

Wednesday 8 December 2021

Aylesbury Court House - Xmas 2021


Finally regained my video content mojo finishing a 5 minute bespoke vid for EMF that runs dec-early jan

Tuesday 2 November 2021

Bye Bye Boaters

 All things shall pass, and my delightful sojourn as a Lock Keeper on the Upper Thames has come to an end for now.
I have to say it was a thoroughly enjoyable time and a simply delightful way to spend the summer.
Even though the job is gone, I still have the occasional money spider hanging from the brim of my hat and I can always find a swan to talk with should I have the need...

Wednesday 15 September 2021

Saatchi Gallery - Holotronica

 Yet another gig - soon be into double figures...
It was odd in a lovely sort of way to be away from calling in boats and wrestling with geese and be back doing something that is second nature to me. 
I pulled at least 6 rabbits out of hats on this one..

Wednesday 14 July 2021

Almost did some work

 Had a projection job whose success hinged on the English ball kicking team winning which they didn't. So that was that. Probably just as well as it was raining..

Monday 22 March 2021



Taking a 6 month break from not doing anything for a whole year.
I'll get to wear a uniform and I won't have to say 'would you like fries with that'..

Monday 1 March 2021


 The best part of two days in bed with a high fever after a dose of the AZ vax.
Not an ideal way to spend a weekend.. Oh hum