Lucas Dittebrand posted a nice video on YouTube demonstrating how to create a perfect mask in Photoshop that can be loaded in Resolume so the video only shows though on the objects on the wall. Very nice trick!
Lucas Dittebrand wrote:here's a little guide:
The resolution of the second screen should be the resolution of the output in resolume (e.g. 640*480).
In photoshop you create a file with the same resolution (transparent or black background)
drag the window to the second screen.
press "F" two times to go into full screen mode and hide the rulers if visible (cmd+R).
Choose the pen tool "P" and select "shape layers" in the bar at the top (first button).
I usually choose red as the foreground/shape color.
Now draw one square with the pen tool. if you draw a second shape, a new layer will be created automatically.
with the shapes it is possible to fine tune the squares, if you didn't put the corners exactly. Just use the direct selection tool "A".
When finished (delete the background layer and ) save the file as transparent png.
Now load this image as a mask on the composition in Resolume.
Thanks for that link Bart - I also use a similar method for buildings, but use the Brush tool with shift which gives a solid line. The problem with this is that the page moves if you track too close the edge and the Pen tool doesn`t seem to do this, which is great. I will try it on my next building - this weekend - the problem might be seeing the pen tip at a distance. A big hassle in building mapping is keeping track of the brush tip!.
I usually multicolour a Map for a building and then make a series of black and white masks for all of the components such as the windows, the walls, edging, special features etc. This way one can isolate and effect any component of the building - i.e. show video in the windows, whilst a graphic is on the walls and the edges are colour changing. Once the pre and post mask render switch is implemented this will make this technique and resolume even more awesome than it already is.
Quick question - do .swf files import with their sound? Mine don`t seem to
ps if you don`t have photoshop then ProMotion will do the job and it`s much cheaper. So will Artrage but it`s mostly freehand with rulers.
-Project a white fullscreen solid with Resolume
-take a picture of the screen with you camera as close to the projector as possible.
-in Photohop open a new file with the same resolution as you Resolume output
-load your picture and drag the corners of your white solid to the corners of you photoshop file.
-Now you can make you masks in different layers by drawing over the picture.
disadvantage is that you can not always make a picture from the projectors position.
advantage is that you can go home and make your masks there instead of on location.
I never had problems with wrong lens types or with the fact that you are always a few inches next to the lens when you make the picture.
Hi Gdlt - This is very interesting as the best so far I`ve managed is to mark key points on the building and then try and stretch the foto to fit which often requires cutting it up the middle vertically and stretching the two sides sererately. Mostly these days I`ve gone back to doing most on site. Currently I`m doing a ruin and nowhere do the corner edges of a resolume full frame hit the building. Also I use a lot of wide angle .8 lenses where a fraction of inaccuracy results in the mapping being off for details like window frames et My experience is that a longer lens projection is much closer to what a camera produces. There is a program DX0 which can flatten out fotos for `proper cameras and lenses` but invariably I have a compact on site and anyway what lens is on the projector affects the registration. I`ll definitely give it a go though because yeah it would be nice to do more at home and less in the street or in a field. cheers JMac
If the corners don't hit the building you could also project a grid instead of a white solid. and then use this grid as a reference in Photoshop.
For the lens types: the mapping i did was mostly on flat surfaces with objects of almost no depth, maybe this is why i dont had any problems with it.
Maybe another way to check if it is working for you is to project the edited picture with Resolume again? I have done this too but the low brightness/contrast was a problem for me (wich i think can be solved with a Resolume effect, but i never tried).
I just got Resolume 3 yesterday so have been experimenting with video mapping. I am trying to follow your tutorial but I don't understand what you mean by dragging the window to the second screen. I am having limited success I think this could improve if I could follow the tutorial fully.
The final image is a little big, I am just practicing trying to map an A4 sheet of paper on the wall, hopefully I can move onto something more complex.