Moving Shadows/Light on Characters

[bupaje]

Hi, new user here .... I just got and started going through the tutorials. I am wondering if there is a sample around or someone could just give me a general overview on how I might do something like on the animated Tarzan series on TV and cast shadows from branches on characters when they are under the trees, or when I have my fish in the water if I want there to be the effect of light rays or shadow areas as they swim.

I'm not looking to create a shadow for every tree but say paint a fixed layer of tree branch shadows and/or light rays/water ripples for the whole scene and mask it so that it only shows on the characters and as they walk under the trees etc you could see this very slight shadows and light spots appear to move on them as they walk.

[Lost Marble]

Here's how you could accomplish this effect - download the following Moho file:

http://www.lostmarble.com/misc/masked_shadow.moho

If you play back the animation in Moho you'll kind of see the effect. Export it as a QuickTime or AVI movie to see the full effect.

What I did is put the character (or multiple characters, depending on the scene) in a group layer called "Masking Group". In the Layer Settings dialog for the group layer, go to the Masking tab and set the Group Mask to "Hide all".

Next, for each of the character layers (in this case just one), go the Layer Settings dialog, Masking tab, and set the Layer Masking to "+ Add to mask".

Finally, you need to add your shadow layer. In the sampel file, it's the layer in the group called "Shadows". For my shadows I just quickly drew some blobby shapes and blurred the entire layer a bit. I also set the layer blending mode to multiply. You could instead use an image layer that you hand-painting in a painting program.

The result will be that the Shadows layer will only be visible on top of the character, and not on the background. You could animate the shadow layer a little bit if your trees are supposed to be moving in the wind.

[7feet]

Another thing this technique is useful for is just the opposite, simulaing beams of light in a shadowed area. I did a test piece where I wanted the character walking across an unlit room to walk through the beam of light being cast by a daylit window near the "camera". most of the setup was the Same as Lost Marbles, except the masking layer was a rectangle that covered the entire frame. Inside the rectangle were some clear spaces that defined where the light beams were, and the rest was filled black, but with the transparency set pretty high, so in the end it looks like the entire room is in shadow except for the area where the light is cast..

--Brian

[bupaje]

Thanks very much for the explanation and example. I'm off to play with it right now.

Thanks also for the explanation of using it for light beams as well.

Burt

[bupaje]

Just as a small follow up I tried this technique using an animated 3D object as the shadow layer and it works. I think this can be used to advantage to do what I tried to explain here http://www.lostmarble.com/forum/viewtopic.php?t=937 but won't repeat it as it will likely sound confusing again.

Anyhow here is a quick mov for those who are interested and the moho file below it -nothing new here, just what LM suggested but put it here for the sake of completeness.

http://stormvisions.com/moho/masked3drotate2.mov

http://stormvisions.com/moho/masked3drotate2.moho