Light and shadows on 3D objects




I am working on piece that I airbrush onto lycra. It has a mandala structure with some 3D elements.
I would like to get your idea's on how to get my work properly 'lighted'.
My main problem is that I don't have the experience of drawing (on paper), and that casting shadows is all new to me.

Let me explain:
Rougly the artwork will consist of eight big diamonds, eight smaller ones, and a central octagon. All will be connected to eachoter with fishwire, will measure 10 diametre and can be attached to the roof of a venue.

The colours will be a rainbow gradient, throug the different shapes.

I finished one of the small diamonds. I want them to look 3D, as if you are looking to it from an angle. The borders of the diamond are meant to be round. I tried to create that look by casting shadows on the sides.
My biggest problem here is making shadows and highlights meet when there are intersections of different borders.
So far, in my opinion, it's looking ok. Not high level, but I've got to paint all of them, and not spend months on it ;) Any suggestions on increasing realism is much apreciated.

But now, the octagon needs to be done. That thing has a lot of diagonals meeting eachother. And I'm a bit scared about merging the different shadows and highlights in a decent way. The light will come from 'right under'

Especially the center: I really don't know how to make eight '3D' rounded lines merge...
My main question is, how do you guys figer out the way it should look?
And apart from the lighting on each diagonal, I think the right under side needs to be lighter as well?

Fyi, in the middle of the octagon, 'inside' the octagon, I will airbrush the green Polyhedron picture.As if it is stuck inside. Looking forward to that one :D

Many thanks in advance!

Really cool design, just my style. I can't help you out much with your dilemma. I still fight with trying to maintain just one light source. Sometimes I think my work is lighted by a mirrored Disco Ball. But, cool beans on your design. You'll figure out how to make it work and look great.

Well there are no rules in art so... hehe. It's your own style and YOU decide where the light and shadow falls. The general guideline or "rule" in art for light and shadows is your light source and where it's coming from. When an object is not actually 3d, you have to paint the light source in perspective of where the art will be viewed. Such as on a car doing emblems. If they are going to be looking at the hood emblem from above, wouldn't the light source be in perspective of the viewer looking down at the hood from normal eye level? Making something that isn't 3d into such, is just a matter of creating an optical illusion. Remember this, people don't see what you do, but what you didn't do in your creation. I live by this mantra.
Thanks for the replies!
The lighting is getting better and better as I am making more diamonds.
Still don't kow realy know how I wil figer out the octagon though :p

(edges of the lycra will be cut away)
Apply the same thought to the octogon, but one intersect at a time, remembering what angle the light is coming from.
This allows you to imagine what each individual joint will look like.
Yeah, that's true about the joints, good tip.
I think my main problem is this:
With the diamonds all intersection are lighted the same way: one half is a dark side, the other is a light side.
But if I use that echnique wih the octagon, that would start looking silly, and especially not realistic.
I think I will have to change that. I might have to make interesections with more shadows or less? That non intersection is the same?
That sort of scares me :)
Just think about each leg of the joint and how the light is going to fall on it.(And where the light is coming from)
This might at least give you the starting point of each, separate shadow on the joint itself.
finished the center...

hard to photograph the blacklight, but gives an impression:
Light source direction is the key to making it appear 3d, I think the light source is a bit off on the tubes in the back making it hard for me to see the depth.
That could be the camera use or just my old eyes.
Looking at your image the light is coming from the right? and going to the left.
This being the case then the left side shadows would be darker and the right side ones slightly lighter in appearance.
I remember this thread.......came out amazing in my opinion.....great job!
thanks for the kind words :)
I'm not sure where to start a thread though, as I'm not really familiar with this forum.
In which category would you put it?