Projecting image on wall matching Room perspective (workflow?)

[Jeroen Prins]

I probably need to clarify some

We want to project an image on a white wall. The projected image shows the room behind the wall, therefore the image should match the perspective lines of the real room. The effect we want to accomplish is to see the room behind the wall matching perfectly. People can see the projection from a marked position in the room.

Setup is as following;

where room 1 is the existing room and room 2 the impression/animation.
There is only a small area where people can look from, because of the perspective. (a bit like streetart/Trompe-l'oeil)

We first wanted to match the perspective, so we projected 3ds max on the wall. First problem occurred because you cannot have a floating viewport to match the perspectives accurate.
I thought i can make a photo from the peoplesview, draw the vanishing points in photoshop and use this as a texture in 3ds max (but the photo itself has some perspective and distortion on it too..)
The camera settings should match the human eye as close as possible (read something like; filmgate 35 / focal length 45mm) somehow i do not get a convincing look, too much floor, doors to small.

Is there a good workflow to accomplish this in a convincing way?

Hope someone has some ideas, i'm breaking my head on this one

[flino2004]

you have two point of view, one is the from the people and the other one from the projector
you take the view from the people's perspective and you have to adjust it to the distortion of the location of the projector. Since you have the projector aligned in XY the distortion of the frame would be minimal.

In PS is like selecting the four corners of the plane where you want to project the image using crop (perspective-ON) now is a flat and you match those four corners with your projector.

this is simple because your are using a simple plane, when you have 3D planes like building with multiple projectors it a lot more complicated.

[Jeroen Prins]

Hi Flino, tnx for shedding light on this one!
I didn't thought of the distortion of the projector would matter.. So basically i can try to put the projector more up, so it matches the final view more, and the distortion would be minimal. The rest i can transform in PS.

Does it make sense the vraycam target should be straight? (not looking up or down)

[flino2004]

The camera could be anywhere, it's where you want to get the effect for the viewers... Mapping projection only works an specific point of view. Imaging that the camera is a projector and the projector is a camera recording what you are projecting... After you get the film you invert the roles to play your film back. now you have to correct the distortion from where you captured because the projection plane is the same but the cone of the projection and the recorder are different.... To understand it better imaging that both(camera and projector) are way separated in xy. There is a video posted recently in evermotion about a mapping projection project using an Audi R8 model, the graphics where done in Cinema4D, most of the applications for mapping and calibrated projectors are for apple. I did a lot research about it for one project that I did with some friends for Turner in Chicago.

[Jeroen Prins]

Hi Flino, i didn't had time to get on with the project and probably someone else is taking over.
Thanks for the info! i will pass it through.

[flino2004]

You are welcome!!! Good luck!!