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View Full Version : how in the world to do this.


Wesball
09-07-2002, 10:50 PM
I went to this site to check out images of Tree Maps...

and I found this animation... from what they are saying... the tree's here are planar with image maps of their trees.

http://www.marlinstudios.com/products/vtf/forest_test02.mov

so how do they get "depth" to the trees when the camera looks straight down?

I'm looking for an economical way to do a big forest so I'm curious.

:surprised

Tottebias
09-07-2002, 11:02 PM
2 Polygons mapped with the same image crossed, like a + sign.

Wesball
09-08-2002, 02:01 AM
That would work from shooting down the z and x axis...

but when you look straight down along the "y", you would see the cross shape wouldn't you?:hmm:

particle
09-08-2002, 02:48 AM
This is just a guess, but I think they used 3 polygons per tree. One in each plane, zx, zy, and yx. If you scroll through the video slowly there seems to be a point when it shifts from the side views to the top view. I guess you could use gradients to make the vertical poly's transparent at a certain camera angle and have the "up" facing one become visable. Another weird thing is the circular shadows, which is why I think they used a ploy in the xz plane. Just my guess though.

particle

Norbert
09-08-2002, 05:10 PM
$200 for a disc of tree & clip maps...

Screw that. You can make your own, with infinite variation, for less.

Look here: Jungle 3D (http://www.gardenhose.com/products.htm)

SplineGod
09-09-2002, 05:20 AM
You can create trees in a variety of ways. How you create trees should also be driven by each shot. Trees that are close up will have to be built mainly with polys. Mid to far distance trees can be done by mapping trees onto polys. You can also use hypervoxel sprites and use an image of a tree as your sprite. Another method is to create trees or shrubs using hypervoxels and then baking them.

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