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3d user
06-30-2005, 10:08 AM
I'm trying to get a darker shadow for my object in a simple lightdome setup. An object sits on a white floor and should cast a darker shadow.

Captain Obvious
06-30-2005, 01:05 PM
Reduce or remove the ambient lighting.

Surrealist.
06-30-2005, 02:58 PM
If that doesn't work, well I thought the dome trick was to simulate a radiosity effect which can give you lots of "ambient light". Anyway, you can apply this trick of light exclusion in any case. It can appy to just about any light set up where more control is needed.

Just remember - as Capt. Obvious pointed out - ambient light lightens up the shadows so you will have to contend with that also with your set up. However, in the real world the shadow would be lighter under these conditions.

But here's a little trick that will give you some controll, say using a spotlight or an area light to get control of the shadow, remebering of course that the distance to the object with an area light affects the look of the shadow. Closer to the opject will make the shadow more opaque.

In the example below there is one light and two objects(not including the ground plane).

One object has this "shadow light" excluded so it has no effect on it's surface nor to cast a shadow. This is the object in your scene that would remain lit from the other lights, though you would turn off the shadow options on those dome lights.

In the example below it is not being lit since there is only one light in the scene and remains black.

The second object remains affected by the light however has "unseen by camera" checked in the object properties render tab. It is merely a clone of the first object and is there only to cast a shadow but not be seen by the camera

This way you can control the lights that effect the object's surface and those that effect it's shadow separately.

toby
06-30-2005, 06:22 PM
You can always use a gradient backdrop, and adjust the colors' brightness overhead or on the sides - but adjusting the image in a 2d app would be the easiest.

Surrealist.
07-01-2005, 12:40 AM
Oh I wasn't even thinking of that kind of a dome set up. I was thinking lights.

toby
07-01-2005, 01:06 AM
oh - if it is lights then I think he will have to do it post.

Surrealist.
07-01-2005, 02:54 AM
Could be. But we don't know anything yet do we? Could be an animation. But I think that light trick I gave (not of my own invention of course) might help though in ether case.

Sooner or later he's gonna come out of the woodwork and tell us or post a pic.

Things just sail along too fast around here. :)