3d from a photo

[westiemad]

a year is a long time to go mate, do u know any 3d software at all? Lots of cubes, then duplicate and scale ;)

AnDy

[Bonedaddy]

What is this for, exactly? Depending on the application, you could fudge a LOT of it. Camera mapping, cards, matte paintings, there are many ways to get around building an entire city.
Hell, the big houses usually LIDAR scan a city rather than build it. What are you trying to do with this?

[Elvis75k]

Basically i have to do a simple fly-thru-sequence, i don't need too much details (textures on the building, etc.).. I've already set up some boxy stuff, scaled them but ther's too much in density!!

Someone, time ago tell me about software that take the shadows from the picture and (Pythagorean Theorem) take the real scale of any part of the shoot.. Who know him??


http://www.elvis64k.com/cg_help/ortofoto_build.jpg


ps.. i'm a maya user..

[westiemad]

Start looking at satillite websites, they use something like that to generate 3d models of the earth, and the government tally the recon photos with satillite ones to generate 3d models :)

AnDy

[maX_Andrews]

this is a good time to use displacement maps. A displacement map is a black and white image used to deform a mesh shape. Te white parts of the image will deform it the most, the black parts will not deform it at all, and everything in between dforms more and more as you get closer to white.

So I took your image in photoshop, made a new layer, and made grey shapes where the buildings are, using photoshop's "polygonal select tool."
http://www.renderring.com/misc/displace1.jpg

Then I did the trees using a small brush, and touched up a few areas. The final map looked like this after only a few minutes.
http://www.renderring.com/misc/dusplace2.jpg

Now in my 3d app (bryce, but maya does it too)
I loaded the black and white as a displace map and the other image as a coor map. This is what I got.
http://www.renderring.com/misc/displace3.jpg

The quality loss is because I made the image 4 times bigger for a better resolution. The building shapes would looks better if I started out at a higher resolution.

If you spent more time you could use different grey values for each building so they would be at different heights. For example, dark grey for low buildings, light grey for high buildings, etc.

Hope this helps!

[Elvis75k]

hehe, thanks a lot!! :surprised

[Bonedaddy]

Originally posted by maX_Andrews
this is a good time to use displacement maps.

Oh, dude, good idea. I'm going to use that. Thanks a bunch, that's usin' your noodle.

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