The January 2012 Tutorial Discussion

[Gare]

What is probably confusing is that the shadow is very soft at the edges, and also that shadows are what?

Shadows are NOT just areas where a single light source is stopped by an object. A shadow also happens, in addition to—if you understand what I mean—where naturally-occurring light, ambient light, cannot reach a surface.

Yes, objects cast shadows, but darker areas, which we might not even call a shadow, occur when light cannot get to an area.

This is scientifically called "ambient occlusion", and this is what my modeling program is doing.

Also, the front of the icosahedron is pointed and it, too casts a shadow, although our eyes fool us because a 2D scene flattens this 3rd dimension and we don't expect it to cast a shadow.

Let me grossly simplify the scene, okay? No tricky ambient lighting, nit very photorealistic, though...



-g-

[Drwyd]

Well here goes, this is my attempt at a isocihidiron, icosihidroon, ihosicedron ......... that funny shape.

[Gare]

THAT is TOTALLY wonderful, Drwyd!

You nailed the shading, took the trouble to soften the edges, your lighting and shading is way cool!

And I don't know how to spell "icosahedron', either. It's a "polyhedron", or "polyunsaturated", usually.

My Best,

Gary

[Drwyd]

Thank you Gary

It still feels a bit "floaty" to me. I may add a textured ground to help land it.

[Gare]

What might also help the anchor is deepening the shadow closest to the object. Shadows, more evident on hard surfaces outdoors than soft, ambient lit ones, have a shadow umbra and a penumbra; I refer you to Wikipedia's entry on it.

Also, to keep it from floating, put something heavy, like a garden brick on it.

—Gary

[jvila]

WOW everyday We learn something new, shadows are like languages It gets complicated when you have to learn it when your old, until now shadows were just shadows, now I don't dare to say what they are .

Our ignorance carries us safe along the road hehehehehe.

I'm keep on reading about this topic, I'm still under a very dark shade

[Drwyd]

2nd attempt

[Gare]

2nd attempt

I could stand to see the primary (camera right) shadow a little darker, and this might be an artistic thing and not a photo-accurate thing, Drwyd. Sometimes we need to telegraph a point, and this involves straying from photorealism. If you see drawing of the human hand, many of them are beautiful and also a little on the fantasy side with the proportions. Because if you look at a lot of amateur photography of human hands, they often look like claws because they're not posed and lit properly.

Your drawing is largely above criticism because you know what you accomplished that many do not when copying a photo or other tonal source?

You didn't add too much contrast. I see so much work done by Xaraists, so much effort, and instinctively they've made their work too contrast-y, too much separation in different areas.

And your piece did not fall prey to this human tendency. As humans (which excludes me, of course), we are attracted to bright colors and our minds crave separation (contrast) to make out geometry. And unfortunately, a lot of us carry this misperception into our artwork.

Me? I almost want the top left face to be brighter, but I suspect this would be wrong.

Bottom line is if you are happy with it, Drwyd, you're done and probably have other things to do, including being proud of your accomplishment.

Keep it up!
—Gary

[Gare]

WOW everyday We learn something new...(

That's what I like about this new area on tg for The Xara Xone, Javier. Learning and sharing; I think I've learned quite a lot myself from member feedback already! And we haven't had any fighting or bragging yet, either!

Wait! No bickering or petty baloney? Is this really a forum??!

—Gary

[Big Frank]

i've been away for a few days but am following this dicsussion with great interest

gary, i'll reply to you later if i can, if not, it'll be tomorrow

take care everybody

f