[Trance-R]

Wow, Frost! I like I like! So do you wonna do some explaining why the shadow is grayish instead of dark dark? And how you traced the reflection on the glossy sphere?! PLEEEEZE?
BTW, I am gonna try these alright~ =) just need the weekend. What's the deadline teachers?

Spooooooge! I can't download that psd.

[This message has been edited by Trance-R (edited May 24, 2000).]

[freddy flicks stones]

Thanks Spooge for going the path of the whip cracker. I think after writing all that info, I feel like I hammered enough for a moment, and got a little soft on the critiques. I see this is real deal, so I must put on the whip cracker hat too. I think it will take me a few attempts, gotta get my sealegs back.
You guys must listen to these critiques, they are not meant to be eye bashing. They are just the simple facts. Don't get bummed out about them, use them to your advantage. That is what they are here for. Every time you hear critisism, absorb it, and immediately attempt to correct it. Don't let any negative emotions get in your way or it will slow your learning process down a bit. I see it happen way too often.


Spooge, doyou know the name of Hugh ferriss' book? I saw it a while ago, and it didn't even register that it might actually be a rare and hard to find book. Hey, thanks again for the crits...

[This message has been edited by freddy flicks stones (edited May 24, 2000).]

[AliasMoze]

Oh momma! Those look good, Spooge. Can't get the PSD file though. Fred, what's the official deadline on this project? I keep getting stuff dropped on me this week.

[spooge demon]

Fixed link. My crit of mine

Fancy edges of cast shadow, no good. Too much variation in cast shadow values. Bad modeling of back cube- not sitting on flat surface cleanly. Light source should be higher, making lighter halftone on top surface. Cubes look a little gray.

Hugh Ferris book is " the metropolis of tomorrow" Get it.

[This message has been edited by spooge demon (edited May 24, 2000).]

[freddy flicks stones]

Spooge, you also need to move your shadow map back just a pixel on the front cube. See the tight edge at the bottom?

Deadline...Wednesday of next week. That way, everyone can get the holiday weekend excuse out of the way...if it's late, it's gonna cost you ten points

[This message has been edited by freddy flicks stones (edited May 24, 2000).]

[AliasMoze]

The weekend is fine for me. Doing some figure drawing too!

[samdragon]

Would you (spooge) be willing to explain in detail,maybe later, how that works?(the info in the alpha channels) I understand some of it, but I can't figure out where some of those "projection"lines came from, such as the ones between the two cubes for the cast shadow of the left cube onto the right one.
Maybe I should clarify that...I'm trying to figure out what method you used to figure out the exact placement of the shadows.
Big THANKS to the both of you for taking the time to put all of this together..enough talking..back to photoshop.

[This message has been edited by samdragon (edited May 25, 2000).]

[samdragon]

If anyone is interested...
I found that book "The metropolis of tomorrow" try the link below it's around $40.

http://www.papress.com/books/0910413118.html

[jasonN]

Lange said:

"I'm always wondering why my art teacher at school don't learn us such things...
I'm learning here more in a week than I learn a whole year in art class..."

Yeah, it's the same with me. I don't think I have learnt anything technical at highschool. Our teacher has never tried to instruct us properly, we always get to just do whatever we want and it's called 'art'. I'm not against abstract forms of art, but it just gets to me how we've *never* been taught anything near as good as Freds & spooge's tutorial.
So thanks Fred & spooge and thanks to the rest of the board for being the best teacher I've ever had. *No* thanks to the education system in Australia!!!

-jason

[Trance-R]

I agree with JasonN! Canada's public education school art courses are useless too. All you do is collage and some kidish cut and paste stuff. No real technique nor tips like this wonderful once-in-a-while thread. Thank you Freds & spooge SOOOOOOooooo much for starting this informative session! Frost, I wish you could do some detailed explaination of your sphere... I've been waiting for two full minutes!

[This message has been edited by Trance-R (edited May 25, 2000).]

[Plop]

Try 2
The shadows are too long on top and right cubes. I just noticed after scanning it in.



Fred, thx. I did darker shadows on this one. I'll do more at different angles tomorrow.
As to the being offended... pls be as harsh as you want, good critique usually is.

Spooge, thanks. My forms sucked i did it in a rush and didn't construct too good. I'll try to watch my lights too tomorrow.

Once again thanx to both of you guys, this is so helpful.


[This message has been edited by Plop (edited May 25, 2000).]

[Nex]

I have the feeling something's terribly wrong.





[This message has been edited by Nex (edited May 25, 2000).]

[klaivu]

had to add a little texture

hmm. now that i look at it, i see that the shadows are fucked.


[This message has been edited by klaivu (edited May 25, 2000).]

[Frost]

Trance: Now I regret posting that -- it was way off topic. =( For the reflections, I assume Fred and Spooge will be covering that later on, and I did a bad job of it... in the case of the sphere I should have used rays from the center of the sphere towards the corners and points of other objects and then intersecting that ray on the surface of the sphere ... and I did it wrong, but, I just got carried away in the fun of it all. Anyway, it would be fun to go over that in the future.

Spooge: Thanks (a lot) for the input! I didn't really notice that while I made it, and just a few hours after, I see it all now. =) Btw, what did you use to make the example render of the cubes? (the shadows split as though there are two slightly offset lightsources).. used shadowmaps instead of raytracing? =)
Another thing, in the example shown, if BOTH the cubes and the surfaces they lie on are of the same material and have the same properties, wouldn't it make sense (by means of real lighting and radiosity) that the shadow would also get the same sort of light refraction as the dark side of the cube? (in a single light scene) Maybe we should study light from raytracing instead of quick renders. (or am I splitting hairs?) (sigh) Thanks Craig.

[This message has been edited by Frost (edited May 25, 2000).]

[Darkmoon]

Hehehe you may all commence laughing..... now!






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Darkmoon
-Seire Hirez,
-Hirez.org Staff =^..^=

[tanis]

[mOO]

ok heres my 2nd try at this the shadows are really screwed up though.


[This message has been edited by mOO (edited May 26, 2000).]

[Nex]

29A you're right, I just did those very quick and tried to get the values right this time. I updated my picture up there. thx

[This message has been edited by Nex (edited May 25, 2000).]

[Binke]

Practice painting lights and shadows with values, do it you must, help you it can!

Blagh, the sphere is foooked up, and the shadows as well.
oh yeah..used artificial light..


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http://binke.gamesquad.net

[This message has been edited by Binke (edited May 25, 2000).]

[Darkmoon]

lets try this again,
p.s Sc00p is a god



only one this time....



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Darkmoon
-Seire Hirez,
-Hirez.org Staff =^..^=

[IO_Error]

Spooge, Fred, I'm having trouble figuring out how exactly the construction lines work for a shadow, or even a cube whose edges don't run parallel to the vanishing points, like in Spooge's example. Could one of your elaborate on shadow/irregular form construction in 2-point perspective?
Unfortunately in the real world, all objects don't sit on a grid perpendicular or parallel to a set of vanishing points.

Thanks,

-=IO_Error=-

[Stolln]

Spooge and/or Fred...I just had a thought while looking at all the images people posted...

Maybe a good subject (for further columns, tutorials, etc.) would be about the parts of a shadow, i.e. the umbra and penumbra. Although it may not be the biggest tip, I've noticed some people don't really know about the penumbra and the effects on the environment.

Could be a little tid bit of technical knowledge.

Just a thought. (Oh, and great job everyone with your stuff. Thanks to Craig and Fred for putting this all together as well.)

[samdragon]

Ok..let the beatings begin!!!
I can't seem to get the cubes on the ground without using some "artistic licenses". I wasn't sure how much of that was allowed.
I better go now, I think I see spooge coming down the hall with his cane, or it that fred..can't tell it's so dark....


[This message has been edited by samdragon (edited May 25, 2000).]

[Francis]

This post is in response to one or two people who asked about shadow construction. I sketched this out mainly to show how the vanishing points of shadows relate to the 2 vanishing points of the geometry.

I know it's line art, and I know my values aren't too suave - I do want to take some time to do the exercise, but I have two cents on the shadow stuff that I wanted to toss in first.

Hopefully the diagram is self-explanatory, but basically shadows have their own vanishing points which can be arbitrarily placed as shown. The sunlight vanishing point is placed somewhere in the sky, and represents a light source which is essentially parallel, rather than a cone, like a spotlight. We assume this because the sun is a bazillion miles away, and so for all intents and purposes, the light rays are parallel.

In this example, the shadow vanishing point is placed on the horizon line, which indicates that the sun is pretty much on the horizon. I could have lowered the shadow vanishing point (but keeping it lined up below the sunlight v.p.), which would give the effect of the sun moving closer to us. If I lowered the shadow v.p. until it was below the cube on the drawing, the shadows would start to point away from us, toward the top of the page, and this would indicate that the light source is behind us.

Obviously there is a lot more to this, but it's one simple way of constructing a convincing looking shadow for this exercise.

I hope this was clear. Let me know if there are questions or if I screwed this up in any way.

Thanks for your time.



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TeamGT Studios

[samdragon]

Oh, if you could only see the light bulbs going off in my head! Thanks for the tip. I have never heard of such a think in my life. That's great info to have. I'll have to redo my cubes now! thanks

[burn0ut]

awesome, i never really knew how to do shadows like that.. thanks francis/fred/spooge

[synj]

i love you moo :~)

-synj www.synj.net

[AliasMoze]

Doh, sorry I just reread your post. Sorry.

BTW, I got so excited plotting these drawings that I'm gonna spend all day Saturday on these things. Very cool lesson. Very "no excuse."

[This message has been edited by AliasMoze (edited May 25, 2000).]

[This message has been edited by AliasMoze (edited May 26, 2000).]

[spooge demon]

I will continue to beat knots on people until Sunday night, when I may disappear for 6 weeks. That's why I was reluctant to get involved with this. Could not see it through.

***sharpens the axe***

The point behind this exercise is to be very aware with the two most important aspects of a rendering, drawing and value, in that order. In this particular instance, resist temptation to vary from the assignment. As I said, no crutches to make your pic "more interesting." Limit yourself to just value and drawing and the simplest forms and lighting and surfaces for now. You have to isolate these vital things and make sure you understand them.

If there are departures in my crits from what light would actually do, I have a good reason for doing so, and it is to increase the clarity of the forms expressed. a good example is the slight darker tone behind one of my cubes to create an edge to bring it out slightly. I might also ignore some esoteric effect because it is confusing. It is not a good idea to allow your forms to cross the eye level, for example. Less clear as a quick read.

Fred, that line is interesting. It is not a line in the traditional sense, but a cast shadow from the tiny radius on the edge of the cube. I was taught this way, so i follow it. If you don�t use this, how do you show the turn of that surface? Gotta change value somewhere. In other disciplines (like head drawing) you area taught that every object has a thickness, and even a radius where the form turns. It is a minor point, and I remember debating it with my instructors and losing

Frost, my cubes are done in PS only. I used masks for the shapes. The softening of the cast shadow edge is refraction, you see how the farther the cast shadow edge from the edge that creates it, the softer the edge is. This is a function of how diffuse the light source is, but also a characteristic of light going through or around an edge. I don�t remember my physics to well, but I think it has to do with the wave-like properties of light. But it is does help identify the shape as a cast shadow, and helps the read of the forms, so it is included.

Later, when we get into cast and form shadows as applied to figure drawing, we will play up the SHARPNESS of cast shadow edges. A contradiction? No, just a play on the relative hardness of cast and form shadows. Right now, the cast shadows get softer in the described way to contrast with the sharper edges of the cubes. They describe each other through their difference.

Also in my assignment, I said use natural light. You can use either. I used artificial in mine.



Roll your own, or go to the cube farm.


A couple of definitions:

Forms- the 3-d objects that you are trying to describe on a flat surface

Shapes- 2-d areas that attempt to increase the feeling of 3-d form.

These two terms mean something different, and I use them precisely

On to the paddlin�

***women and children leave the room***

Plop


Two different eye levels, or cube not sitting on surface normally. Chose different direction for light source. It is tangent to a face of the cubes, leaving one face either in light or dark. Ambiguous. NG. Left cube is not a cube, too deep. Right VP is not followed in two back cubes. Be more precise in your construction. If you cannot eyeball these things correctly yet, as you will eventually, plot them out so your eye learns what is correct. Won�t worry about values yet. Get drawing right.

Oh what the hell. Separation between lit and shade not enough to dark in lit halftones. Top of right cube is too bright in relation to the tops of the other two. Shaded side should go darker

Ahhh linedrawer!!!! get it away!!! Use VALUE to show form, not line.

Nex, don�t use linework, the values are imprecise as is the drawing. Shadows stand up on surface, use different EL from objects. Ellipse of bottle too open. Just cubes for now.

Klaivu, Gray objects, values too dark overall. No texture, just matte forms, please. Cube is out of convergence, shadow side of cube darker than cast shadow. Use one light source. Missing shadow edge from top edge of cube. No reflected light into shaded vertical sides.

Darkmoon-

Grey cubes on white surface. Make cubes white. You can use tonesi n the background. No cones or spheres yet. No reflected light in shaded side. Need slight gradation in lit sides to show light direction. Too dark in halftones on sphere. No lines! tone behind will help with that. Verticals are not vertical. Shadows not following perspective.

That�s it for now




[This message has been edited by spooge demon (edited May 25, 2000).]

[Binke]

You better believe that's a paddlin'

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http://binke.gamesquad.net