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March 22nd, 2006 #241Registered User
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heartbeat... you seem to have the theory down for casting shadows from an artificial light in perspective. the way to figure out where your shadow vanishing point is is drop your artificial light source vertically to the floor. it's that easy. you drop it where ever you want your light source to be in space. longer drop the the floor and your light source is closer to the viewer.
i whipped up a quick basic example:
for sunlight when the sun is in FRONT of the viewer, you just drop the position of the sun onto the horizon line and that gives your vanishing point, for sunlight when the sun is BEHIND the viewer drop the light source (sun) to it's inverse position below the horizon line (for exmaple, sunlight behind and left of the viewer has the light source placed below the horizon on the right side of the view) then pull your shadow vanishing point UP to the horizon line and intersect ray lines and shadow lines like usual.
now, keep in mind that this is a real quickie thing and there are more rules for shadows cast on vertical surfaces, over round or complex shapes, etc. that link that idiot apathy put up is a really good resource once you understand the idea and can wade through the terminology.
***edit*** for the record, you shouldn't really have the VPs on the page, as the cone of vision is really only a small area between the VPs, they're just here for demonstration
Last edited by uRiDiAN; March 22nd, 2006 at 02:41 PM.
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March 22nd, 2006 #242
March 28th, 2006 #243
Finally set aside some time for this! I re-did Project two and strted project four.
This time i tried to put more energy into corrrect saturation and value and not rendering, so it's not very pretty. I looked over some posts and decided that in the shadow, the red block and the blue block should both stay fairly saturated in the shadows, because they only reflect thier respective colors, while the brown block should decrease in saturation. I tried to plot the shadows, but I may have gotten the red block's shadow wrong, and the saturation in the shadow it casts on the brown block should be lower, in afterthought.
Not much to say for this, except it's not done, and for practice, I tried to vary the lightsource and reflectiveness (is that a word?) of the spheres.
Thanks for everything Idiot Apathy! More soon!
March 29th, 2006 #244
@Everyone: Sorry that I've been so neglectful of this thread lately, been a lot to do and a lot on my mind. I've lost track of who I've responded to and who I haven't so please post a link to your previous post if I haven't yet commented on it! Ah, P.S. If there is going to be renewed interest here, should we try to get this thread moved somewhere with more traffic? Maybe the sketches and wip thread?
@Cup of Joe: Nice, I like the colors mate. Now the shadows, just their shape for right now, should be uniform and predictable for each block; Right now your blue block looks like it's being lit from maybe a ceiling light and the orange block perhaps from the sun or a light from the side. Blue block's shadow is a little strange but I can't quite place it; On the orange block you've forgotten the hidden edge towards the back I think. If you have the time mate, I recommend going over the shadows in perspective links and demo posted above and doing just some really simple cubes and blocks. If you feel like doing this post them here and I'll give you what feedback I can . Trust me mate, I know how you feel about these shadows, hard stuff! On Colors: I think it looks good, but your wording leaves me thinking you might be a little confused. Any object will only reflect "their respective" colors as you put it, so if the light reflected off a apple comes back to the apple it will increase the intensity. If the light reflected off a grape comes back; more intensity. Off a watermelon, etc etc. Now, what I think you should be thinking about is what kind of light is reaching the shadows? The blue shadow for example, say we are in a room, the blue shadow side is recieving light reflected off the ceiling, the walls, parts of the table, some of the orange block probably, and get this; from it's own cast shadow even (don't let that confuse you, it's not usually a noticable effect). Now consider the red block, it's recieving light from many or most of the same places, perhaps to a lesser extent however as it is blocked a little bit by the blue block. So you might think that it should change a little more than the blue shadow, perhaps darker and less saturated relatively. An important factor in choosing saturation on the red blocks shadow would also be how much light is reflected off of the blue block, becoming blueish light, is hitting the red shadow? This should not only change hue but dramatically effect saturation. Now, keep in mind this is all going to be relative to you local colors and several other factors; just keep thinking about these things and it will become second nature . Man, let me know if any of that was confusing...
Ok, next ! A good try on the reflected light on the spheres. Do refer back to Briggsby's post on spheres though, it should help you create a little bit more convincing sphere It really helped me out. I can see you thinking here, good stuff mate. Where's the cast shadow on the blue sphere ?! Ok, where you've reflected the colored paper back onto the spheres, I think your right in thinking that there would be less of an effect near the cast shadow but I don't think it should be that drastic. It would be recieving light from many areas not just the area where the cast shadow is, make sense?
March 29th, 2006 #245
That's fantastic thread. I was lurking here for a long time but finally decided to post something.
When I paint in Photoshop, I usually use quite dull colours + low contrast. My paintings always looked much better in free program Artrage. It has different pallette which I like more. There are hues mixed with different saturations and brightness setting is on seperate slider. It suits me more beacause I have easier control over value.
Today I finally noticed something so obvious. I didn't realise that I can change the settings for colour picker so that it can look very similar to this one in Artrage. From H/SB to HS/B. To me it looks better this way
Last edited by Farvus; March 29th, 2006 at 10:06 AM.
March 29th, 2006 #246
@Everyone: Keep an open mind on color and what I've said and possibly what others have said as well; I know I'm still discovering many things and many different interpretations. This doesn't mean that things posted before are wrong, it just means that they aren't always and/or necessarly right. Use them as guidelines and find the truth in your own mind
@Farvus: Really nice! I love how the purple turned out. Great value and saturation changes I think. As I've said before don't worry too much about your values not matching perfectly, the system for converting them isn't perfect and the exercise was really just a way of tricking people into thinking about how value fits in with color. Your english is really great by the way, but watch out for things like "a" and "the" . Looking forward to your takes on the next project!
March 29th, 2006 #247
Thanks for taking the time to respond Idiot Apathy!
I re-did project two again. I thought a lot more about light reflected from one block to another. I also plotted out the shadows correctly , although I think the edge on the brown block's shadow is off the page. I think my problem last time was mainly an uncertain lightsource and a hastily plotted horizon.
I also have a few questions in general.
(1)- Increasing saturation before a shadow makes an object pop, but how is this done in grayscale?
(2)- I usually start a sphere or surface by painting the whole thing it’s half-light color, because I think of that as it’s “true-color”, is this correct?
(3)- Saturation x Value= Chroma? What is the purpose of knowing the Chroma?
Thanks again for everything!
March 30th, 2006 #248
Nice, good to see you thinking about it man. Shadows, still a bit funky; they are a bit confusing aren't they? I can't tell you much about what a shadow should look like when it hits another object (like another block) as I'm still trying to figure that out. But on the more simpler parts of shadows just make sure that all your shadows share a common vp, that should simplify a few things. Now, again on the orange block you didn't factor in the back! Just to make sure you get what I'm talking about here's a pic:
See the "invisible" back corner? There should be shadow there too! My lighting is different than yours but you see what I mean right? Now man, next time your free I want you to do a cube in 2pp leaving all edges visible and plot out a lightsource and the shadows, ok?! Post it when your done!
Your questions: That's some harder stuff...
1: I don't think that translates into grayscale, grayscale is a focus on values, probably just look wierd if you tried to simulate it I dunno, experiment a bit let us know what you find out.
2: Yeah, thats not a bad way to think of it. You might look into Local Color though, it's a widely used term in art and usually thought of as "true color" Half-light can be influenced by several things so I'm not sure it could be called "true". For me, an objects "true color" is what it would look like on a nice clear day, maybe at noon or so
3: Chroma, man... not the guy to ask about this; still wrapping my head around it I think. Check a few posts back where Briggsby was talking to me about it, some really good stuff there. Or, if he's around, ask him !
March 30th, 2006 #249
Hi guys, just got time for a quick thought about question 3 (must... get... sleep!).
Along with hue, tone and chroma are the parameters of choice for traditional painting, I think because it is a comparatively direct matter to judge them visually, i.e.:
Tone = relative position on a scale from white to black,
Chroma = relative visual distance from neutral (grey).
Saturation and value (in the specific senses that I've been using them) seem to me to be more relative concepts, not so straightforward to judge visually, but almost essential for creating shading series - and hence creating the illusion of light.
In painting with traditional media I tend to use tone and chroma as my primary frame of reference for most of my analytical thinking, both for finding the main colour components of a picture, and for fine tuning colour variations. I switch to thinking saturation whenever I need to create an accurate shading series of one particular colour.
It seems to me to be a huge bonus that saturation and value are handed to you on a platter in Photoshop. Nevertheless, I think I would still be using tone and chroma as my main frame of reference for many of my analytical processes in digital painting. Bear in mind though that this is a complete newb to digital painting speaking.
Great to see this thread moving again!
March 30th, 2006 #250
Wow! Thanks for the replies Briggsy and Idiot apathy! Got some real work done today. I finally feel like I'm making a little progress.
D'oh! I don't see how I missed this corner thing! I thought you were talking about something completely different. Thakns for the answers too!
Thanks for clearing that up!
Here's today's work.
1- fixed shadows.
2- I did that 2pp shadow you asked me to do. The fisrt one is with all the guidlines and such, and the next is just the shadow and the block. I didn't fill in the shadow because I did this in Illustrator, and I don't know how to do anything in that. (Another thing to learn)
3- Tried out some things for my question no.1. Basically did a sphere and converted it to grayscale to see what changes in value there were around the saturated area. There were none that I noticed, but I may play around with this a little more. I'll post them both here in case there is something in these I'm missing.
4- Did a study on complementary colors. Probably could have used a ref, but I'll post it here. (I know the shadow is wrong, but this was mainly a color study, so I forgot about it.)
Thanks again for the help everyone!
April 2nd, 2006 #251
I had an idea today, and decided to post it here. I was wondering if two blocks of the same color were placed with two lights, and the shadow from on block lay on the other, but at the same time, light from the opposite block reflected onto the shadowed block, would the saturation actually increase instead of decrease with value? I checked it in life, and sure enough, It worked!
Here's the end result in photoshop (real quick)
And heres the basic setup, since my explanation is confusing.
Does this mean I might be beginning to understand this?
April 3rd, 2006 #252
@Everyone: See the post above? If your experimenting with anything! ANYTHING art related, I want you to do what Cup of Joe did there. We can either help you or learn from you ok?!
@Cup of Joe:
Ok, sorry I haven't got to your last post yet but I wanted to get to you on this latest one while it's sort of fresh.
Now, if your thinking the shadow would be more saturated than the part in the sunlight that's incorrect. If your thinking the shadow on the front part of the second block (rear) is more saturated than the back of the second block (rear's rear) that's probably correct.
If your getting confused think only in terms of light, how much light is in the shadow, what are it's properties? How bright/dark, what hues' are contained in the light etc.
Ok, now keep in mind that there are many factors included in having your shadow increase in saturation and it really only takes one factor to mess that up.
I wish I had more time to think this through, sorry! Let me know if you have any questions.
In the meantime, I want you to think about a yellow block next to a red block. and a green block next to a red block. I want to see what you come up with, and do try to experiment in life if possible.
Last edited by Idiot Apathy; April 3rd, 2006 at 01:53 AM.
April 5th, 2006 #253
Added this to the main page; be sure to check em out. Will get to other stuff soon! Sorry!
Links to Some Other Threads You Should Also Participate In / Will Come in Handy
Digital Painting in PS
Bumskee's thread about some great basics and not so basics on painting digitally.
Don't worry it's pertinent to photoshop and painter, and the rest really.
New Artists Seeking Help Come Here!
Looks to have some great potential, just popped up.
This is Infinitum's baby, emphasis seems to be on drawing, lighting/shading etc.
Not entirely sure of it's complete scope, however you will probably see me in there brushing up some skills
April 6th, 2006 #254
@Cup of Joe:
#1: Looking better mate! #2: Nice, you did it perfectly I think. How about if the lightsource was lower down and you had to factor in three corners? #3: Nice looking sphere! You read the Briggsy post didn't you? Watch the shape a little bit though, remember your looking at a round object and can actually see well... around it. Picture a hemisphere if that helps. #4: Ouch ouch... completmentary colors and so bold. Hurts your eyes huh? I remember when I was studying a little bit of this that... well I almost went blind ! My eyes really hurt. Now complementary colors should blend to gray and back again, i.e. red becomes duller and duller until it hits gray and then it will become more and more saturated green.
April 10th, 2006 #255
Well I've finally got in to posting my stuff. I first saw this thread when it was only quite new and I would have posted back then but I couldn't join CA for some reason...but anyway thanks heaps to you Idiot apathy and all who have contributed to this thread. Its taught me a lot! Also thanks to Briggsy and your efforts here describing Ashtons and the tasty Jaffa...mmmm Jaffas If only I lived closer to Sydney ..
So I did Project #1 ages ago and now I've done it again with better results. Like Briggsy has advised I chose the center-light, full-light, half-light and shadow colours/values and blocked them in. I then blended using the knowledge I got from the thread Bumskee started (linked at the top of the first page of this thread) and added the highlight.
Getting better but not quite there yet..
April 10th, 2006 #256
Glad to see this thread getting some new people! I'm still pretty new to this, but I'll try to help. The main thing in the first one is just that I'd have liked a little more saturation to make it pop, which you did in the second one. The second one turned out great! the values are pretty close, but I think the red sphere could use a darker core shadow (Correct term?). Hope this helped, and keep at it!
April 10th, 2006 #257
April 11th, 2006 #258
@Everyone! : Read this post! Should help with sphere construction.
@Bhud: cool, glad to have you here. Spheres look good, and you've accomplished the objective of seeing values in color. Only thing that I can think to mention is your structure, do look over Briggsy's Jaffa post and the link I posted just above. Do take into consideration what Cup of Joe has said however think about why a sphere would look dull or intense, and realize that you could actually have both right next to each other, think about how that's possible too.
@Cup of Joe: Thanks for helping out dude! Sometimes these replies take so very much time, really nice to see when others are replying as well. Check out the last half of the reply to Bhud by the way, I don't think it best to think that a red object should look exactly the same each time, think about what the "local" color is, and what the lighting is. Cheers dude!
@MattGamer: Heya dude! Looking forward to seeing some more from you. Quit being lazy :|
April 12th, 2006 #259
Cup 'o and Idiot Ap. thanks a lot for the crits guys and yup I totally agree on all points. For some reason I felt a bit timid in creating darker values not sure why. I've jumped to the 3rd one now as I found a cool pic on ImageAfter that inspired me to do something a bit more ambitious but still within reach...will go back to the spheres soon though as they have been very helpfull.
So I started trying to just sketch it by eye using the border and negative shapes to get the proportions right but it was well off. I think I would have learned a lot if I had persisted but I really just wanted to focus on getting the values sorted and tackle that foremost in this study.
I traced a rough shape just to get the overall proportion in perspective and then chose three values that I'd try and make the image from. Next step is blending and cleaning up the edges. I'll do some more tomorrow when I don't have to work
April 13th, 2006 #260
Trying to learn a little about color, I have a hard time with the color of the shadows, would love some crits and suggestions!
April 13th, 2006 #261
Bhud- Nice! It still looks a little lighter than the original, but it may just be the white BG making it look different.
gl0gg- Very nice! You did very good on the reflected light. Very bold going for nearly all complementary colors, but I think you nailed it. Nice catch on the orange block turning slightly gray from reflected green light. The only thing I see wrong is that you forgot that not only would the block reflect light on the floor, but the floor reflects light back at the block. (This would normally raise the saturation and value of the block, if only slightly.)
Glad to see this thread making a comeback! Keep at it guys!
April 15th, 2006 #262
awesome thread dude i love it!!!,
i just found it today and sat down all afternoon
until night and read almost all cant wait to
wake up tomorow and continue on page 4 :-D
Idiot Apathy i respect your dedication and
your work is so inspiring such beautiful color
management and application so so damn good
im just staring at your sketch thread
so cool , dude im so excited hahaha ill post
my comments soon on that one,
mr briggsy@ashtons posts are so good too
i have to re read those im still with the
idea of a less saturated light side and more
saturated midtone depends on how the
highlight reflection spreads on the object
washing it away overexposure maybe ??
dont pay attention to me i just wanna write
a lot of stuff here hahaha is very inspiring
i should check bumskee PS thread too
so many things to learn from all you guys
i wanna learn X-D !!! good posts
of ChrisMayernik too i enjoy reading those
looking forward to more post of everyone
keep up you guys are doing great !!!
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April 15th, 2006 #263
@bhud: Looks pretty good dude, I want to stress that tracing isn't bad or anything; use whatever means necessary to learn and get you to the point where you don't feel the need to trace ok? However like any crutch if you rely on it too much it will eventually make you weak instead of help you become strong. Now that you've got down what you think you see I want you to use the color picker and see what value the different shapes are and what value you chose to depict them. If I remember setting up this project, it wasn't to match values exactly but to still have them relate properly to each other, i.e. something that is light should still feel very light next to somethatthat should be dark. Next up look at the lenses in the goggles, parts of them actually have some of the darkest values in the picture. Try not to see the lenses but instead break them down into smaller, but still simple shapes and figure out what value those shapes should be. Cheers dude, hope I don't come off as too critical here , your doing good and I want to see what's next ok!?
@glOgg: Cool color palette, I call it swamp boggy! I think this looks great, but I can see a little confusion in hue shifts am I right? Ok, talking just about what happens to the color when it's receiving more light here: Your red seems to become warmer into an orange, yellowish-orange seems to become a purer yellow, and your blue becomes more cyan, all this to me implies a Yellowish lightsource. Nice, playing around with tweaking your colors a little bit to show warmth perhaps? I'm still on the fence to whether the sun is warm or actually white light, but that's for another time I think. Lightsource looks nice; time for shadows! Red becomes a muddy-orange, looks like your adding in the green swamp ambience right? Yellow - also a shift towards the swamp green, nice; you might have tweaked this a little bit thinking about how much or how little reflected light might be coming from the blue block. Blue, I think perhaps should have a larger shift towards the swampy green, especially since they are fairly far from each other on the color wheel. My only real problem I think has to be the shadows cast on the green swamp grass, what's your thinking in turning them towards a purer green/cyan-green? Are you perhaps thinking that reflected light from the blue block is the influence? It would have an effect but it would perhaps be overshadowed from more green swamp ambience or even the sky etc etc. This is something you might want to toy around with as well, accentuate or exaggerate "subtle" changes like what might happen to the greengrass's shadow from the blue block and the red block, but think about what part/parts of the shadow would be influenced more. I can see this with the blue and yellow block on the lit swamp grass but not much elsewhere, your right in thinking that they would probably reflect more light because they are recieving more light, but also think that the grass is recieving more light and would interfere. I think it's actually easier to see hue shifts etc in shadows because of less influence, i.e. think the glare on your computer monitor or tv caused by the sun. Now not only in the green shadow, but perhaps in the blocks themselves could use a little bit of this treatment as well yeah? Also, how about a blue sky into the equation? I think it's probably correct to think of the sky as the second biggest lightsource in most occasions perhaps. Values look really good, I'm also happy to see you thinking about outside edges and inside edges like on the red block, less light more light you know? Good lord, this is basically a long winded reply meaning, really nice job; you probably already thought of most of this stuff, you might enjoy experimenting with these ideas a little. Nice "shape" on the shadows by the way, looks pretty accurate I think - but then again I'm still trying to figure shadows out. Did you sketch/plan them out or eyeball it? If you have a sketch of it or whatever I'd like to see it if you have the time. Peace dude, oh and please read my reply to Cup_of_Joe as well
@Cup_of_Joe: Careful about reflected light, your right that adding light will always ad value I think, however saturation is dependant upon what color properties the light contains. I.e. if you have a green block and your adding the same color green light, reflected or otherwise, it will increase the saturation. Now, I think perhaps it's right to think that if you mix any color with any different color, no matter how slight the hue change you will loose value. It will get a little more complicated however if say your lightsource is very bright, I think this would mean it's white or contains several hues (still working on that), so potentially it could raise the saturation of whatever color is contained in the lightsource. ... Confused? me too... How about this, think of a pure red lightsource with no other influence and now shine that lightsource on say a cyan object - your cyan object won't be lit up at all (technically speaking it absorbs all the red light). Just something to think about, hope I don't come off as being critical mate! Think about tweaking/exaggerating effects like these, bending reality or even breaking it if you feel so inclined - you might like what that produces, I really enjoy experimenting with this sort of thing. Cheers dude!
@gaboartpage: Really cool to see you in here man, I sent you a PM by the way. Can't wait to see your stuff in here mate If anyone else is reading this check out his SB!
Uwaaa ! That took an hour!? Crazy...
April 18th, 2006 #264
Ok ill chip in wiht some comments later, I just found this place and
I had the urge to give this a try as Im not nearly as good handling color
as I should be so, here I leave you the first two excersices, heck this
is harder than it looks
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April 18th, 2006 #265
Cup o Joe - Thanks for your input, it's very appreciated! All that stuff to think about when it comes to colours and lighting
Idiot Apathy - That's a great reply, but a little difficult to understand everything you say there. I am going to read it a couple of times more and do some adjustments on the picture and get back and see if I get it.
The shadows you ask, they are just eyeballed. I have calculated a bunch of shadows the uridian way (see the top of the thread) before, and I think it's easy to get them at least pretty correct if you just try and trace the beams going past the corners of an object while trying to keep the perspective in mind. I can imagine people have different methods when trying to eyeball shadows. I hope you can understand what I wrote here
April 19th, 2006 #266
coming in a bit too late ( the thread is seeminly dead)
but it seems that this is the perfect place for me to learn hoe to paint Digitally "properly"..
here are two of the basic things
gonna go through the other stuff too just as as soon as I get the chance
April 20th, 2006 #267
Idiot Apathy: Thanks for the crits dude. No way are you being too critical. I'm always open to advice and find it extremely helpful and never disheartening. I've been deviating all over the shop and studying all sorts of colour theory (I really recommend one by our mr FredFlickStone http://www.lemenaide.150m.com/ that's not posted here in CA) and learnt that I should take a step back and focus on form/values before colour so here I am again
So anyways I thought I might go for something a little more simple like a funnel. I can see that I've gone a bit too light again. Not sure why I keep doing that .. oh well
April 20th, 2006 #268
1. value vs. color
2. mehran - Your spheres are outrageous! The green light on the orange sphere is practically perfect!
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April 23rd, 2006 #269
Excellent, excellent thread. Here's my attempt at the first exercise, with more to come.
With this exercise I did the grayscale sphere first, and I was going to use a much higher yellow for the next one than I did, but because yellow has such an inherently high value, I ended up having to tone it down quite a bit. Maybe I'll try it again with the color first.
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April 28th, 2006 #270Registered User
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I've got two attempts here for the first exercise.
The first batch looked pretty nice overall, I thought, but it seems the values on the color sphere were darker than the grayscale:
I decided to try again.
My second batch took a long, long time (the first took about 30 minutes... This was closer to... two hours.) and the disparity in the values were farther off than the first batch... Ah well... Maybe I'll give it one more go tomorrow.
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