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Shade01
02-17-2006, 04:43 PM
Are there any camera projection techniques that allow for more extreme movement of the camera than traditional front projection techniques? I want to do a city fly through but I would prefer to paint the textures and project them on top of geometry as opposed to actually modeling everything. Thanks for any ideas.

jeremyhardin
02-17-2006, 04:59 PM
i'm not sure if this will help your particular case, but one thing i do to get the benefits of front projection without the drawbacks is layout my UVs for my object in a paintable order (not Atlas), front projection map my desired texture onto my object, and bake the surface color to an image with Surface Baker.

then I take the baked image into my paint program and paint detail where I want it, while knowing exactly where it will rest on the geometry. I also use this to paint detail that wasn't there, like spec/diffuse maps and bump maps. Finally, I paint into areas that didn't project well and fix texture problems there.
i UV project these images back onto my object. This can also be mixed with multiple projection cameras. So one camera projecting from the X axis (for X-facing polygons), 1 from the Z, 1 from the Y, and bake it all to one UV, then do the same steps above.

is that what you're looking for? or have I missed the point entirely? :)

Shade01
02-17-2006, 05:16 PM
i'm not sure if this will help your particular case, but one thing i do to get the benefits of front projection without the drawbacks is layout my UVs for my object in a paintable order (not Atlas), front projection map my desired texture onto my object, and bake the surface color to an image with Surface Baker.

then I take the baked image into my paint program and paint detail where I want it, while knowing exactly where it will rest on the geometry. I also use this to paint detail that wasn't there, like spec/diffuse maps and bump maps. Finally, I paint into areas that didn't project well and fix texture problems there.
i UV project these images back onto my object. This can also be mixed with multiple projection cameras. So one camera projecting from the X axis (for X-facing polygons), 1 from the Z, 1 from the Y, and bake it all to one UV, then do the same steps above.

is that what you're looking for? or have I missed the point entirely? :)

I think I kind of get what your saying, but its hard for me to understand that as just written text. One thing I know I don't want to do is UV map an entire city :)

jeremyhardin
02-17-2006, 05:55 PM
well, to skip the uv mapping step, you could just have as many cameras as you want to project from. here's a simple example with cameras from x, y, and z projections.

jeremyhardin
02-17-2006, 06:01 PM
here's one of the texture channels, and a preview of the render camera moving (while the other cameras keep the projections locked.

Shade01
02-17-2006, 06:48 PM
Thanks man, appreciate it- I'll have a look at all of that when I get home.

PixelInfected
02-18-2006, 12:04 PM
a good tutorial for electric image is on
http://features.cgsociety.org/story_custom.php?story_id=3344&page=
you can do same thing with lw without problem.

jeremyhardin
02-22-2006, 04:05 AM
ok here's a simpler scene i mocked up. only 2 projection directions, so you get some streching, but if you were to do more you could eliminate this. notice how the 'render_camera' is free to move about, since it's not being used to project any textures.

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02-22-2006, 04:05 AM
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