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View Full Version : how to..constant floor color, with shadows



blindsided
10-06-2008, 09:20 AM
Hi all,
I feel like my lighting skills have got worse of late, and I am struggling with a look that I am sure must be easy to achieve.
I have created a ground plane with a model on it.
I want the plane to catch the object shadow.
I would like to have the background color set to white, but i would like the plane to look solid white so that it merges with the background without a 'seam'

I have been trying to achieve this effect by increasing the luminosity on the ground which obviously affects the shadow.

and i find that i i can see where the plane meets the background (or alpha) quite clearly.

Is there a better way?

thanks

Hopper
10-06-2008, 10:01 AM
It would probably be much simpler to create your ground plane as a large sphere (or bowl) so that you simply eliminate the horizon alltogether. Or at the very least a large ground plane with walls that slowly curve perpendicular to the plane - so you have a flat area to work with.

Sekhar
10-06-2008, 10:07 AM
You could set alpha to shadow density for the ground (see advanced tab in surface editor). You can then use the resulting alpha to key out the ground areas you don't want.

If you don't want to composite, you could use the shadows node in DP Kit (a cool set of plugins). What you do is: for the ground, create a shadows node and set its output (e.g., soft) to the diffuse shading (NOT diffuse!) input. And assign color of the ground to that of the background, of course.

blindsided
10-07-2008, 02:49 AM
thanks for the help, i will try both methods.

daforum
10-07-2008, 02:59 AM
You can also try using background fog.
Set the fog colour to the same as the ground plane, then set the max/ min distances to just inside the far edge of the plane (you may have to play with the distances until it looks right)
You will have a ground plane that will show your shadow and a background that will look seamless.

Iain
10-07-2008, 04:05 AM
You can also try using background fog.
Set the fog colour to the same as the ground plane, then set the max/ min distances to just inside the far edge of the plane (you may have to play with the distances until it looks right)
You will have a ground plane that will show your shadow and a background that will look seamless.

Quoted for agreement.

The only problem with this method is that the fog interferes with some forms of lighting i.e. if you have a sphere with a HDRI mapped to it, the effect of it's lighting will be lost.