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Projection on 3d geometry

Hi everyone,

This is my first message here and as far as i can see, is the only site where it can be answered ;-)
I´ve carefully read the tutorial “how to project on 3d geometry” which was quite interesting. This tutorial has a section called “Virtual Camera’s perspective is different to real world projector position” and offers an example with 2 projectors setup.
My questions is… has anyone idea about how can be this done with another 3d environment? like Cinema 4D. I find working with vvvv really interesting, but sometimes i need other kind of programs for making my 3d visuals.
Can anyone help me with this? I would appreciate any kind of help
Thanks a lot!

Hi manambros,
i´ve not tried it before but i can imagine a solution based on a few photos of the real geometry (a building maybe?)
In the 3D tool, use each photo to match the perspective of the virtual object in to the real one, and reder each camera in diferents videos.
Then put the diferents proyectors in the same position that you have taked the photos.

I hope it could be usefull.

Thanks for your response Iasal,

If i have correctly understood your solution, i think that i will continue having the perspective problem because each one of the projector´s view will be different than the spectator´s view.

A clear example is an sphere. I will need at least two projectors situated in opposite sides of the sphere. Then the spectator will be positioned in other point of the view completely different than the others. Then every 3d effect that modifies the real shape of the sphere will be different depending on the point of view that we choose (projector 1, 2 or spectator view), there is a perfect example of that here (look “Projecting on two sides of a house with one perspective”)

In other words, projectors should project the image from their position taking into account the spectator´s view, not their own view (aarg!!)

Thanks for your interest, i really appreciate your answer

aagghh!!!..my login timed out, and that was a looong post i had written. in hindsight probably too long, but what the heck. anyway i shall summarize.

i do architectural visualisations. i use Lightwave 3d software.

i measure the venue. (only 1 so far)
build a 3d copy of the venue in Lightwave.
i use Lightwave’s CCTV texture plugin on various parts of the 3d venue which show the spectator point of view.
combination of show/hide scene objects.
record scene from projecter(s) point of view.
…basically the same as the vvvv example. (or is it the reverse)
still have problem of only 1 optimal viewpoint.
and clips are venue specific.

…you could give everyone in the venue a pair of wireless 6 axis tracked glasses which each show a unique point of view. each one has it’s own networked computer running it.

conclusion: the venue goes bankrupt from buying equipment, everyone gets their head fried, and you knock out the local power grid.

the new ‘Projection Man’ in Cinema 4D might be of use.

hi manambros

in vvvv project on 3d shape means project on a surface witch is different than a flat screen… means create a sort of augmented architecture or augmented sculpture.

witch is completely different than a prospective projection with point of view…

the point of view in the tutorial is just to show you the result but at the end in that case we don’t really matter about the point of view because each points of view are correct.

may be if, may be i understand correctly what you need, you imagine to have something like this made by johnny lee.

witch is theoretically possible using vvvv but may be the tutorial you are looking is not the correct tutorial.

hope to be helpful

ciao
alessandro