[idiot]

I'm working on the Fred's cube exercises, and I'm having problems constructing shadows that fall on adjacent objects. I haven't been able to find much information despite the fact that everyone seems to know how to do it but me. The book I own on perspective (Perspective for Comic Book Artists - David Chelsea) doesn't even deal with the subject. The only tutorial I have is from TeamGT



This is great if I'm working with parallel cubes, but what if they are at different angels? Where would the line between the left vanishing point and point aa go? I don't know! What about casting the cube's shadow onto a sphere or cylinder? Or vice versa? Or what about the shadows here



I ran the left line of the shadow (on the middle cube) from the base up to the light source, but I was guessing, I don't know if thats right.

If you could point me in the direction of a tutorial, or a book that deals with this, I would appreciate it. I'd just order another perspective book, but I'm afraid that it might also just skim over, or ignore the subject, and that's all I'm really looking for (info on shadows). So if you'd recommend one, or give me any help I'd appreciate it.

[IDrawGirls]

Sorry ... didn't remember the question. Wanted to reply in the middle class

Not sure if I understand the question correctly ...
and not sure if the explanation helps.

Think about it as a wall ...
along the points on the ground under the lightsource and under the edge the shadow is cast on.
The blue line on the ground in my image ...

Part of this wall is the point that casts a shadow on the other object.
You find it if you draw a line from the light source through the point that casts the shadow.
That line crosses the edge the shadow is cast on.

*cough*

Hard to explain. If I find a better explanation I'll edit the post



I didn't actually find your light source so I was just guessing when I drew in the lines.
Hope that helps somehow.

Oh and if you want to find the point that a corner of a cube casts ... then it's the other way round.
As seen in the image that you posted.
Still thinking about it as a wall can help.

The point casting a shadow on the edge of the far cube doesn't need to be constructed ...
because the line from the other point on the surface to the VP takes care of that.
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[idiot]

Thanks for responding Andy, it does help to think about it that way. I guess we might as well continue this conversation over at the thread on conceptart. But if anyone else here at sijun knows anything about casting shadows on adjacent objects, or can recommend a book.... please feel free to respond here or there.

[jfrancis]

Shadows are a volume.

In your mind, you need to be able to intersect one volume with another.