[Lev_0]

I just found out how to do smooth gradients after I was almost done, gonna restart on the same cubes next week once/if I can get some feedback hehe.

Here's the info I was working with although I'm not sure it's all appropriate for the set of cubes I have (like the 20% shadow angle on the shadow faces).

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Gradation of lit sides- Half-tones

Need slight gradation in lit sides to show light direction.- Need halftone gradation in lit top of cubes (halftone is what is in light that is not highlight)

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Gradation

With our cube, we have defined planes, with no soft transition between them. Thus, we have no core shadow any more, just a sharp plane change with a very hard edge. While this object isn�t round, it still has value banding on each of it�s surfaces.
On the direct light side, you can see the values go from very hot in the upper left hand corner, and a bit darker in the lower right hand corner. The same with the dark side and the secondary light plane. Unless the light is very large, say like a sun, there is always going to be fall off from the most intense spot of illumination. Look at lights at night, brightest at the bulb, and quickly falls off in a circular halo surrounding the hot spot, and quickly fades to black.

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Gradations

There is value transition happening on every surface of everything, even in the shadows.

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Dark value on shadow side of cube

There would be a ridge of very dark value at the base of this edge. The area where there is no bounce light hitting the face. It would start at the closest bottom corner to us, and expand up the face at about a 20% angle up and off the face of the cube...this is again, the area that the ground plane is not influencing at all, because this part of the ground plane is also in shadow, and there are no other surrounding objects to influence that side of the cube.

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Brightest point in shadow on object/darkest point in cast shadow

The left side of every cast shadow, at the base of every object, was the brightest spot in all the shadow values. Almost too bright to the point that it looked like it was on the light side.This was the hottest point of contact on the ground for all the objects,interesting phenomena...

Values get darkest at the bottom left side of the cast shadow. This area includes the furthest point down from the light source of the cube- however, this point gets the most bounce light from the ground plane than anywhere else. Therefore the ground will absorb the least refraction from the cube because the cube is taking on the most bounce light from the ground.

The shadows got their darkest (in the cast shadow) at the left side bottom of each of the casts. This is the furthest point down from the light source on each object, but this point on each object gets the most bounce light from the ground plane of all the places on each object. So the ground will be absorbing the least refraction from the object, if the object is taking on the most bounce from the ground...read that a few times, I swear it will make sense to you...

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Using values

Values are 0-hightlights 1-3 halftones, 6-7reflected light area, 8 core shadow and cast shadow.


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Reflective light on the cube

You actually get more bounce or reflective lighting toward the top of the cube, not at the base. The darks on the objects you have casting shadows should never be as dark as the cast shadows.



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Reflective light on the cube

There would be more bounce light in the upper corners of the cube, as the lower area of the face will have no reflective light in it. It is too close to the surface that has no light projected onto it. But, the corner where the cast starts will have a bunch of light bouncing onto it because of it being so close to the light ground plane, bouncing white light into it's dark side.

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Shadows loosing focus

An incandescent light at about 50 feet away is going to produce soft edges on your cast, while the sun, as freakin bright and hot as it is, is going to produce sharp shadows. The other variable that affects how soft the shadow edges get is how tall the object is, or how far the object is from the surfaces the shadow is casting on. The only wacky way your edges will be very soft, aside from all these other ways is if you have some sort of softening screen covering your light source. This will most definitely soften your shadows...


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Shadows loosing focus

Shadows loose focus further out from the object that cast them..when a shadow is cast from an object, the edge of the shadow will be sharper, when it is closer to the object.
How much it softens all depends upon how far your light source is from the object, and how bright, or intense the light is also. Where the cast eminates, it should be firm, solid, not fuzzy.

[Sumaleth]

Hmm, where to start.

The tops of the cubes look good to me.

The "leading" edges a) look too bright, and b) are not correct relative to each other. Re: brightness, consider the RED LINE A in this image:



See how sharp that angle is? Now look at how close your values are for RED B and RED C. B is at a much more direct angle to the light source, but the values between B and C are fairly close.

And re: their relative values, note that RED D is actually facing the light source more than RED C, yet the RED C surface is a higher value? That's not right. RED D also looks like it needs more of a gradation.

Now consider YELLOW A and YELLOW B - they are exactly the same value, but there should be -no- values on the vertical faces that are darker than any point on the cast shadow.

Now the GREEN LOOPS areas. The shading here don't look natural at all. There's like a highlight running diagonally through them, with a harsh core shadow on one side, and quite a dark value on the other side. This gradation needs to be more subtle, and it would -perhaps- just get slightly darker right up towards the top (but only very slightly).

In the corners GREEN A and GREEN B there would be a lot of environmental reflection onto the dark sides of each cube. The B side would also be slightly brighter since there is -slightly- less shadow blocking the ground reflection.

PINK LOOP A should be a lot brighter than it is because it has that RED D area -right- next to it reflecting a lot of light into that area. The BLUE LOOP should also be a value or two higher than the same place on the other cast shadow because of the reflected light from RED D.

The YELLOW LOOP would also therefore be a lighter value because it has the back of the first cube and it's cast shadow reflecting light back onto it.

The cast shadow would be brighter out towards the ORANGE LINES where environmental reflection has more impact, and this brightening would be relative to both distance from the join/core, and also relative to how many nearby objects are also contributing reflection. Remember though that no where on any cast shadow should be darker than the darkest point on any sube side.

Also keep in mind that because you've used an unnatural light source, the light actually looses intensity with distance. So the top of the second cube would not be brighter than the top of the first/nearer cube, and likewise the shadow of the second cube would be slightly less intense.

You could also consider un-sharpening the cast shadow precisely with distance. If you get it right, it really enhances the realism.

Also think about cropping the image to a more attactive size. Having the cubes on a huge, uninteresting background is not a good look.

Anyway, there's some initial thoughts. I don't think we ever really nailed all the "truths" with this process, so a large part of it is just experimenting until it looks right.
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[Lev_0]

Thx a lot, lots of things I didn't think about.

1 thing-

"Remember though that no where on any cast shadow should be darker than the darkest point on any cube side."

Spooge posted this for the values so I thought since cast is an 8 value nothing would be darker than that-

"Values are 0-hightlights 1-3 halftones, 6-7reflected light area, 8 core shadow and cast shadow."

Does that mean there's darker value than 8 on the cube?

[Sumaleth]

Sorry, I got that back to front. No where on any cube side should it be darker than the brightest cast shadow point.
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[spooge demon]

Make some cubes out of cardboard and set it up. Look at what is going on and experiment with moving things around. Try to explain the values that you see by using the rules that you already know. If you see something that is not covered, you can make a new rule or disregard it. There are all kinds of subtle things that happen that fall outside of the body of rules that appeared in the cubes exercise. But what is the point of all this? Eventually you are going to start adding variables and complexity but still out of your head. If you make too many rules, and it is easy to do looking only at cubes, you will become overwhelmed as you start adding complexity. So the point is to keep it simple, to do only what has the most bang for the buck.

You really start to see benefits from this exercise when you start adding things. Like one white and one black cube, One shiny, one matte, one black satin cylinder and one matte white cone. Then crash the shapes together to make a lamp or something. Then start adding materials and local colors and values to the lamp. Then try a pulse rifle...

One big thing I see on the above drawing is the shaded side of the left cube would be getting quite a bounce from the lit side of the right cube. I agree with Sumaleth's crits

lev_0, my thinking in reserving your extreme lights and darkest is a way to use the middle tones well enough that you don't need the extremes. I see way too much color dodge stuff and crushed blacks where they should not be in beginners artwork. So that breakdown was done with this in mind. I am always happier if I can make things work without resorting to contrast. Then there really is a different value for every surface.

But the real killer that often slips through the cracks is a good separation between light and shadow, and the old bromide, lightest light in shadow is darker than darkest dark in the light. Given of course equal surfaces and materials.

[Lev_0]

Thanks, I had made some cubes out of white canson paper but the paper wasn't firm enough so the sides ended up getting bent/curved, messed up the lighting. Cardboard cubes sound good. I'm workin my way to the pulse rifle indeed, at a snails pace..

[Lev_0]

2nd attempt, gonna do 1 or 2 more, maybe with dif light positions..hopefully enough to move onto a black cube? Somethin isn't clickin with this latest version, I like the reflected light in the first one better even though it's not as correct I guess. Not sure if I got the reflected light off the right cube's left face onto the left cube's right face right. The cubes I made w/ cardboard don't have the same obvious seperations between gradations, everything is pretty blended together.

[Lev_0]

Made some small updates after some feedback-

-Back right shadow edge same softness since it travels about the same distance from the cube.
-Top right cube face less contrast in gradation.
-Right cube LEFT face more bright since it's turned towards the light more.
-Small problem with left cubes lower cast shadow edge not consistant, think I fixed it, still kind of there but hard to do completely accurately without usin paths I think..or I shoulda been more careful when I started it..
-Right cast shadow corner not joined properly to the cube, fixed that
-Put more reflected light onto the left cube's RIGHT face, not sure if that area's still right, hard to tell from the cardboarc cubes I made since it isn't really defined.

[Lev_0]

Attempted a back light, a lot harder than I thought it was gonna be..both shadow faces on the cubes looked really close in value cept for the reflected light. The 2 inside ones were a bit brighter cause of the reflect. Not sure if it's somethin with artificial light but the left cast shadow and maybe a bit on the right cast shadow had spots that were definately brighter than the darkest point on the shadow face but for the sake of keeping everything seperated I kind of ignored that..did this one pretty quick compared to the first set.

[Lev_0]

Maybe some work needed in the black cube shadow face/cast shadow someone pointed out. Maybe another before moving on. I made a black cube for this one, helped a lot even though there doesn't seem to be much going on in my pic hehe.

http://www.levicon.com/files/cubes.htm

[Capt. Fred]

Hey Lev_O.
Nice cube work
when I saw your back lit one I felt uneasy. I felt it should look more like this following image which is almost certaily less correct than yours, but I just fiddled around a bit, and felt it seemed prefereable somehow like this.
I know that this is you exercise here, but you seem pretty good at , so if you could lend a few comments to my tweak of your image and explain stuf, that would be cool.

(the second/lower one is my tweak)(I didn't fiddle with perspective which might need some fiddling with.. dunno)


And another question to anyone who knows the answer is:
Basically i don't understand reflections very well. This is probably a really stupid question, but could someone explain this relfection n the following photo. How come the light is refleting off the wall and hitting my eye to form to completely differnt 'images' of the light source, A and B.. How come there are two areas the light is bouncing off to reach my eye? I don't get it. I know this is a really stupid question.

[zaar]

Capt. Fred: Here a quick answer to your last question about reflections. There are two kinds of reflections; specular and diffuse. Reflection A on your example is a specular reflection and B is a diffuse reflection. I'm not the right man to explain how the physics work and what the technical definitions of the two types of reflections are... so I'll let someone else do that
btw, it's not a stupid question, it's a really good one!

[Capt. Fred]

sounds bizarre.
don't get me wrong, I believe you, it just sounds bizarre: "two types" why not 3? 4? wierd.
Also seems weird to me that I don't understand/have any idea about the way those reflections work, despite them being completely fundamentla and everyday. trully bizarre.

[Lev_0]

I think it's because the surface doesn't absorb the light, instead it bounces it off..maybe the light kind of "slides" along the surface if that makes any sense. I don't really understand reflections too well either but I think it's just because it isn't absorbing any light so it bounces off further down the surface..having the light so close to the surface is probly another reason, I think it would be less like that if you moved it up.

Yea your cubes do look better, although I don't think that's what happens with a backlit light (on the right cube's right face at least). Yours look more transluscent (sp?) that mine do on the right as if some of the light's penetrating through the cube. Generally the only light that's reflecting onto the cube's coming from the ground, there's no light reflecting onto that top right corner of the cube for it to be so bright, but it looks really cool hehe. Then again I used my lamp for this, maybe the sun works a bit differently.

I like the added light you put on the right cube's left face coming off the left cube's back right face, reads a lot better. For the bottom left cube's right face though, the bottom left corner was definately the brightest spot, from there it gradiated to a darker tone in the rest of the face. The way you have it does make more sense though since the bottom left cube's in the shadow, getting barely any reflected light while the right side corner of the face is closer to the other cube plus it's in less shadow. Hmm..

1 more thing, didnt see your A and B thing for the reflection, what kind of bulb and light is that, try taking off the plastic that's on top of the light. Could be diverting some of the light onto the ground.

Edit- Looking at yours again, I can tell it was the reflected light on the left cube that was bothering me a lot, I think that's why yours looks more easy on the eyes. Gonna set up the cubes again and see what was up with that.

More ppl should try these exercises, the html link's posted above for all the steps, if you need some help makin the cube's in PS I can show you..

[Capt. Fred]

Sorry to barge into this thread like I have

But this painting exercise is allot of fun, and infinitly challenging.
I did a quick one, i got the perspective from a 3d problem, i didn't have much time and i was interested in trying to imagine how the light works.



I'd be interested in seing what a more talenteted person would paint over, or what written criticisms can be offered.

To be honest it's stupid of me: I haven't read much of waht has been written so there are no doubt criticisms relevant to other images that will apply to me. But since I've been fiddling with this pic, I'l post it. I'm having trouble choosing 'how matte' these cubes are; if they reflect sharply defined shadows they are reflective; if they reflet very 'blurred' then they are more matte, but how matte is matte... ? I'll read back and probably find the answers.

[zaar]

Sorry if this is going off-topic. I just came back to see if anyone had posted a explanation of specular vs. diffuse reflections. And since no one has done that yet, I dug up this link: Specular vs. Diffuse Reflection, check it out!

[Lev_0]

Capt. Fred- good to see someone else is doin em, post some more! Your cubes look good, here's what I think... I don't wanna come off like I'm some pro at this, I had no idea what I was doing before I started the first cubes up top.

I put my cubes in the same spots as yours, some things I think could be added-

-If you're following the exercises exactly, I dont think the back cube is on the same plane as the first, I haven't checked but that's what it looks like to me..could be wrong.
There wouldn't be so much gradation from light to dark on the left cube's LEFT face, it'd be a lot darker in the far top corner. The reflected light would start around the center area of that face.
Looking at my cubes, the left cube's RIGHT face should have the reflected light more towards the center, getting darker towards the top. The light bounces off the ground and strikes the cube near the center instead of right at the bottom. There'd be a bit more reflected light on the left cube's RIGHT face too from the right cube's face. I think you have some there, it's hard to tell with the small file size hehe. The left cube's cast would be more blurry around the edges than the right and would be more light around the edges. GJ on the cubes, took me a lot longer just to get out my first 2!

1 thing that helps a lot is to use a value scale to pick the basic values for the surfaces, try d/ling my value scale, I put some reminders in there too from one of spooge's posts as somethin to keep in mind. Don't have to follow it exactly, don't think it would work if you did but it's a good starting point.

- www.levicon.com/files/valuescale2.psd

What I do is copy that and paste it into my cubes file on its own layer, then whenever I need it I can color pick from it or hide the layer. Was gonna post my file but it's 30 megs lol.

zaar- cool link, points out some useful things!

[Capt. Fred]

Yeah, cool. Your cricisms are much appreciated. I thknk I might try and find time to do a couple more of these cube set-ups over the next few days. Looking at that value scale, I think I overestimate the amount of light thats reflected..

Oh yeah, on that page you linked to where the cubes-excersize is set out by craig, the link to his rendition of the cubes doesn't work for me. I could proboably learn allot from seeing how that written advice and theory is 'implemented'. Picture's worth thousand words an' all dat.

Ta' Muchly!

[AndyT]

Capt. Fred:
There are some examples. A little small though:
http://anticz.com/drawing1.htm

I just wouldn't make the darks that dark. It makes the cubes look reflective IMO.

I think the value range on most of your surfaces is too wide.

You read that (by Ron Lemen btw ...)?

[Lev_0]

Andy- thanks for the links and info. I think you're right, both values on both shadow faces are really alike, actually I think I made them almost the same value on purpose cause that's what it looked like on the cubes I made, the only difference was the 2 inside faces had more reflective light. Next time I think I'll make one of the faces darker for an easier read. Somethin doesn't look right on my backlit cubes, I think that's one of the things along with all the reflected light in the shadow corner of the left cube.

Gonna read through that other link, thanks!

edit- Andy- the value scale you posted from anticz is kind of messed up. Since it's in jpg format, the brownish green behind the value squares is blended into the values, so if you were to color pick a value sometimes you'll get a really yellowish black value. Probly better to use the value scale I posted, it's made from the same value scale as anticz but since it's in .psd format there's no compression, so nothing is mixed together.

[Lev_0]

Needs work but I don't know where. A lot going on in the cube's cast, cause of the cylinder's reflecting light. Don't think I got that right. I had a cone and sphere in the left area but I cropped it down and tried just these 2 after reading the link andy posted. Cylinder shadow looks wrong but it's "right" in that it's on the same plane, bad perspective choice I think.

Not sure I learned much from this since the cylinder shading was kind of straight forward. I guess I got some practice out of it. Other things that look wrong to me, the cylinder cast and I'm not sure if the cube's reading as black.

There's a huge difference between the shadows/reflected light on a cylinder under artificial light and sunlight. With artificial (I'm using a lamp) there's almost no reflected light at all but under sunlight there's a lot of reflected light so after some debating I put in some reflected hehe.

[AndyT]

Nice .
I think the black cube could be a little darker. Maybe the cast shadows are too dark. I compared it with this one by rdgraffix:

[AndyT]

Another thing: The grading of the cylinder ... I think it should be darker close to the cube.
Right now the form doesn't look right.
That bright white kinda makes it read flat rather then round.
Don't know how to say that ... hope that helps:

[Edit]Or maybe the shadow is placed wrong!?[/Edit]
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[Lev_0]

Thanks, I'm gonna make some changes tonight, I can't work on dark areas like the cube ATM since the sun is shining right on my monitor, can't see anything that's really dark!

Top of the cylinder is kinda bright, gonna change that. The cast shadow of the cylinder is right although since my horizon line is pretty close to the top of the cylinder it stretches out far and at an angle. I wasn't planning on using this angle of light but I wanted to work with the shadow of the cube falling on the cylinder. I would have used a cylinder of the same size too, but I was planning on having a cone and sphere in the forefront, so the cylinder would have to be tall in order to show in the background. At the last second I decided to go just with the cylinder so that's where it's at hehe.
I'll light the cast shadows too, I was tryin to keep them dark so that everything is seperated with their own values but I think lighter would look better for this one.

I'm using an airbrush for these, everything was done with airbrush except for the faces in the light of the cube. I haven't done anything in photoshop except 1 old painting so I'm experimenting trying to get soft gradations. I think right now the best combination I've found is a res of 3000 or lower and low opacity with airbrush. The lower res you go the more antialiasing you get and the less crisp strokes you get which is what I want for this. Sumaleth's pic with the 4 shapes is awesome, he got the gradations really smooth.

http://www.levicon.com/files/cubes.psd - spooge's cubes file

Spooge has a small band of black at the base of his cube starting near the left corner, really helps to bring out the reflection at the left corner. Gonna try and get something similar to that with 2 white cubes.

[Lev_0]

Small 10 minute study of spooge's cube. At first I thought it was the small shadow along the base of the left corner that made the reflected light have more punch but I think instead it's the contrast between the dark value coming from the middle and the reflected light in the corner area. One thing I noticed with spooge's/suma's cubes that were done right is they look good even if you zoom out, mine aren't really doing that, I think this is part of the problem along with me not getting the gradations right. If you alt click and slide your mouse around on spooge's the gradations are really good..
I think even if it isn't as apparent in the cubes I built I'm gonna start putting darker values around the reflected light to make it pop. Think I'm flooding my own thread too, woops. Didn't bother working the shadows in this.

[AndyT]

May I spam a little?
I just can't figure out how to use the airbrush tool correctly

Round objects are sooooo difficult

Thanks for the link to spooge's cubes btw. I didn't have that file.
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[Lev_0]

What program/res are you using? Those look good although it's hard to tell what's going on since they're all zoomed out so much. The cubes don't read as well as spooge's/sumas when zoomed out, same as mine. Gonna do some tomorrow and try and make them read as well from a distance as up close.

[AndyT]

I use the Gimp for Windows. Res of the whole image is 3200x2400 but the cubes are a lot smaller.
Sometimes I even have to scale them ... make them bigger. There are bigger versions if you click on the image.



Well I think I concentrated on capturing the difference between black and white too much.
Some of the values are too close because of that. I think mine don't look like matte cubes.
I'll have to reread the texts and look at good examples.
At least these have helped because I had to do all the steps over and over again.
Now I can try to concentrate on the theory some more.
Too bad I don't know what mistakes I make over and over again.

What I don't get is how Spooge's cubes don't look like Rdgraffix's/Sumaleth's cubes but neither approach is wrong!?
There's so much about spooge's cubes that I don't get.
And it occured to me ... maybe I shouldn't try to give c&c.
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[Lev_0]

Spooge's and suma's cubes are both right, as in they follow some of the basic rules like having reflected light in the corner, some reflected light towards the top of the cube, things like that. Suma's are a bit more light though, I think spooge made his too dark he said. Read suma's crits on my first cubes, lots of stuff there. Duno if you are but try and crop your cubes so that it's only them and the shadows that are in the pic. Then you can look at your image at 100% and it'll be 3000 res and fill your screen.

[AndyT]