Hello, welcome to Proko. My name is Stan Prokopenko. In this video, I'm going to critique the pelvis
lesson assignments that you guys submitted. So thank you for everyone who submitted their
assignments in the Facebook group. If you're not part of the group and you want to participate,
you can go to facebook.com/groups/anatomy4artists, or just click in the link in the description.
Okay, so this first critique is for Gole Senosi. Now, when I look at this, I can see the perspective
is off. And that's actually the main thing that you guys are struggling with, is the
perspective of the bucket. And that's understandable, because this bucket is quite complex. It tapers
from top to bottom, it's tilted forward, it's squished from back to front. So it's not a
simple cylinder. It's kind of complicated. So I want to go over the perspective of the
bucket one more time, maybe a little bit slower and go over a few really important points
that I noticed you guys were doing wrong.
The first thing to start with, is to get the angle of the bucket, the tilt, the long axis.
So when I look at yours, I'm seeing this is the angle of the long axis, okay? So I'm going
to draw that angle, something like that, just draw it in lightly. The second thing is to
get the angle of the ellipse on the top cap, so this top plane that you drew. And you actually
drew that angle correctly, and let me talk a little bit about how you figure that out.
So the first thing I imagine is an angle perpendicular to the long axis, so that's perpendicular
to the line I just drew. Then I imagine the angle from side to side, so the angle you
drew here. Okay. So let's get that angle in there. Now, the angle of the ellipse will
be in between those two. Quite complicated. Now, the reason it's going to be between those,
is because the bucket is squished a little bit. So let's say you have a normal cylinder,
which is perpendicular, the ellipse is perpendicular, the more you squish the cylinder, the more
that the angle of the ellipse will go toward the squishing angle.
So let's say that we squish this along this angle, right? We step on it here and we compress
from here to here, so these points go this way. The more we squish this, the more this
cylinder will become like this. It's being flattened. So the angle of the ellipse will
go from here to here, at a completely flattened extreme. It's just going to be a straight
line, right? We completely flattened that cylinder and it's just a straight line across.
So since we're flattening this bucket from front to back, this angle of the ellipse will
be somewhere between this angle and this angle. So now that we found that angle, we can draw
the ellipse. And you don't have to draw the ellipse in one shot, okay? You can construct
it with a few lines. So you notice how I'm just kind of ghosting it in in sections. It's
easier to do that rather than trying to go one clean sweep in and connecting those dots
perfectly.
Okay, so there's my top cap, my top plane of the bucket. Now I'm going to find the side
plane, and notice how I'm still following this angle here, this tilting angle that I
established in the beginning. Now, it's going to look weird, it's going to look like, "Wait
a minute, shouldn't that be like this?" Well, no. We're squishing that cylinder. If we draw
it like this, we're just making it perpendicular. We're just making a normal cylinder. But since
it's squished, it's not going to look like a normal cylinder, okay? So same thing here,
the ellipse down here will have that same angle. And it's going to be a little bit wider
because we're looking down at it more. So there's my bucket. Now we can find some more
angles that will help us draw the pelvis in there, in correct perspective.
We already have the line from the left side to the right side. Now let's find the line
from front to back. And this is the middle. I always want to make sure it crosses that.
From there, I can drop a line down the front plane if I find the middle of the bottom plane.
I can keep these lines going around the bucket. So it's top plane, front plane, bottom plane,
and back plane. And as I do this, I want to make sure that the lines taper correctly.
These lines go from front to back, so they're getting smaller as we go back. So they need
to taper toward a vanishing point that way.
If I draw this line like that, now these lines get wider as they go to the back. That's wrong.
Things get smaller as they go away from us. So I've got to make sure that these angles
relate to each other correctly. Same thing with these angles. This one and this one are
going down away from us, so they should taper downward, get smaller. We can do the same
thing with this. The side to side will continue around the side plane, down the bottom plane.
And now I'm noticing there's an issue, okay? So we're looking from the left. That means
that if I draw a line from left to right, they need to converge to the right side. Currently,
these lines are getting wider this way; they're going away from each other.
Now, you can always think of a box. If this is the front plane and we can see a little
bit of the side plane. So we were looking from the left side and we can see this left
side of this box just like we can see the left side of the cylinder. So this edge is
farther away from us than this edge. That means these lines should converge. So that
means these lines should converge to the right, but they're not. So I'm going to correct myself.
Something was a little bit off because my drawing is a little bit sketchy. It's not
perfect. My lines aren't perfectly straight. My ellipse, I have a line here and a line
here, so I haven't established the exact position of that edge. So things are going to be a
little bit off. But if you check yourself at every step, you can make sure that you're
pretty close. So that looks like it's a better perspective. So now when I draw, let's say
if I find these corners in the bottom of the ischiums, I need to make sure that they are
converging. They're parallel to all of these, right? So that would be something like somewhere
around here. It would be those dots.
Notice how you are drawing a line this way here. You're drawing a line this way here,
and you're drawing a line this way here. Notice how your front plane is converging as it gets
closer to us. It's doing the opposite of what it should be doing. If you establish the perspective
correctly up to this point, before you start drawing the pelvis inside the bucket, if all
these angles are correct, the pelvis inside the bucket will be more correct. So make sure
that all your angles in the bucket are working before you start drawing the pelvis.
Let's move on to Sonal Prabhune. Sonal, the thing I'm seeing with yours, is you are drawing
these forms, the forms of the pelvis, as very thin shapes. They're two dimensional. You
need to show some thickness to these forms. So for example, right in here, you're showing
the outline but then there's no depth to these bones. Show this, show that there's a top
plane along the iliac crest. There's a front plane in here. You're doing that on this side,
so that's nice. You're showing some thickness here, but then this angle is wrong. It should
follow this angle from side to side, and then drop it down showing the thickness in there.
Same thing in here, you're showing a little bit of thickness but it's just not enough.
The bone would snap like a potato chip if it was that thin. Okay, something like that.
And then you're not showing any thickness at all on this side. So same thing on this
one. Looks like on this one you're showing some kind of lip, but it's not boxy enough,
because you're not showing angles. It doesn't look like it's a top plane or bottom plane
or side plane. In fact, if there was a top plane, you wouldn't see it from this angle,
right? It would kind of go like that, the thickness would disappear toward the top.
But you're showing it all the way around. So it looks more like a lip around the whole
thing rather than thickness. This one's too tall. So with this one, you just didn't get
the proportions of the bucket correct.
Now I want to contrast that with Bae Soo-hyoung work. Notice how much thickness he is showing,
and this feels so much more solid. It feels like he's understanding the forms. You could
feel them in space, right? It's not like a paper cut out that's skewed. He's really thinking
about the perspective and the angle of all these things. So very nice job. I really don't
have a critique for you other than just showing that you did a good job showing the thickness.
Next critique is for Raphael Ventura. Raphael, your lines are just too wobbly. When you're
drawing structure, when you're drawing something that requires a lot of form, a lot of blockiness,
it's good to draw with a lot of straights. So I would say fill up pages and pages of
straight lines. Draw a dot on the page, draw another dot, and try to connect them. Practice
drawing straight lines and make sure that they feel straight. And also, make sure that
you can draw specific angles.
So if I want to draw a horizontal, I should be able to draw an accurate horizontal line.
If I want to draw a 45 degrees, I should be able to draw something near 45. Notice how
you're constructing things with curves. You're drawing the outline of things. And even in
areas like this, where you're indicating a front plane, but you're doing it with just
little swipes instead of clean lines. This would feel so much more structured if you
had just drawn a box, a clean box, for that iliac crest. See how much more solid that
feels?
Much better down here. That's a nice line. That's a nice line. These are nice lines.
Right here, these are all nice lines. So this drawing down here in the bottom right is your
most successful one. Try to redo all these other ones, one, two, three. Do those again
and do them with more structure. I think you were maybe warming up a little bit, and so
your lines were a little sketchy. You were following contours too much, and then you
slowly got better.
Next up is Francesco Franzini. Okay, Francisco, I think you need to study the proportions
of the bucket. Your bucket shape is very inconsistent. This one is very squished from top to bottom.
This one is very tall. And this one is somewhere in between, a little bit closer to what the
bucket actually is, but still maybe a little bit too flat.
In the Facebook comments, Rebecca Shay provided a link to her blog, where she actually measured
the bucket and found the height, the width, the depth. And you could see all these numbers
here. I really like how she went that extra mile and she's studying the dimensions, trying
to figure it out. This is good. Ultimately, we are visual people, I'm assuming, since
you like to draw. And learning these numbers might not really help a lot of us. It's just
this isn't visual; it's numeric and it's kind of hard to imagine sixteen by eleven by nine.
So I think the better approach to learning the proportions of the bucket is what I provided
in the premium section. We have these models, right? We have the model of the bucket, and
the pelvis inside of it and we can rotate it, we can look at it from any angle, and
we could really just study what the bucket looks like from all these different angles.
So the better approach is to just draw a lot of these buckets, and just engrain it in your
visual memory. So then you'll know this bucket just feels too tall, or this just feels too
wide. It's better to go off of instinct than to say, "Oh, is that sixteen by eleven? No,
it's more like 18 by 11." It's just not going to work that way. So if you have the premium
membership, I really recommend going in there, rotating these from different angles, and
drawing the bucket over and over and over again. You have this ghosted architecture
and you can see through it, and then there's the pelvis inside of it. So start with these
lines of the bucket. You've got the ellipse of the top cap. You've got the front to back,
side to side, all that stuff. Draw it in and then draw the pelvis inside of it. And simplify
the pelvis too, how we did it. Instead of drawing all of these curves, you would just
drop that line straight down. You guys probably already know about this, so let's move on.
Next up is Prikka Harvala. Prikka, it's proportional issues. So let's see, this one, too flattened
top to bottom. You could see, actually, it just feels taller. This pelvis just feels
taller. This one looks like it's the correct height but it's just not wide enough, like
you didn't expand these wings out far enough. So you need to show a little bit more of a
taper. In fact, that taper is consistent throughout. Look at these three on the side, almost vertical.
You're showing very little taper, so you need to really push that bottom plane to be smaller
on all of these guys. Okay, so that's a consistent issue. Whenever you're doing something consistently,
that means that you just have that ingrained in your mind already and you have to reverse
it by doing a lot of drawings of it correctly. Otherwise, you're just going to continue making
the same mistake.
I had that with quick sketch drawings, where I would consistently make people's legs too
long. I would just keep doing that, keep doing that. And I didn't know why. I mean, I didn't
even notice it, because it was like that's what I imagined it to be. And the only way
I got over it was to have my instructor come by and constantly saying, "Hey, those legs
are too long." And I would have to just make them shorter than I thought it should be.
But eventually, it just kind of clicked. I would slowly take my perception of it closer
to what it should be.
Okay, let's move on to Brian Williamson. Brian, looks like you were having a hard time finding
the angle of the top ellipse, because you drew five pelvises, looks like they're from
the same angle, except this one. You drew each one with a different angle for the top
plane. So let's look at them. This one is pretty much a circle. Maybe it's a little
bit longer in this direction. This one looks like the angle of the ellipse is going this
way. This one, the angle of the ellipse is going this way. This one, maybe like that.
Actually, no, this one's more like this. And then this one is also very similar to that.
So notice you put five different angles for that top cap. Now, which of them is correct?
Well, let's figure it out.
So the angle of the pelvis is like that. That's the long axis. So let's draw that long axis.
Now, the perpendicular angle to that would be this. But remember, the angle of the ellipse
is not going to be perpendicular, because it's squished. So we have to now find the
angle from side to side, which looks like, in all of them, they're consistently horizontal.
So if we draw that horizontal, that's that. And the angle of the ellipse will be somewhere
in between that, like this. There's the angle that we need to use. And so which one's the
winner? Ta-da! This one right here matches the one that I found here. So this one, looks
like you made it perpendicular to the long axis. This one matches this angle. This one,
not sure what you did there. You were maybe trying to make it perpendicular to the front
and back, not sure. This one also very close, actually. So these two are almost the same
angle. This one, looks like you were also maybe trying to make it perpendicular or parallel
to the front and back.
So hopefully that helps you figure that out. When I draw these, I don't actually draw all
these angles, I just imagine them in my mind. I'll draw the long axis, and then in my mind,
I'll imagine this. I'll imagine side to side, and then I'll draw this. And so I would only
have these two lines, and then I would draw the top cap, bottom cap, and so on, okay?
So it might take a little bit of time to imagine these things, to be able to see that in your
mind, but the more angles you draw, the more lines you draw and the more boxes you draw,
the easier it will be for you to imagine this stuff in your mind. So like I keep saying,
Marshall keeps saying, draw things around you, construct them into boxes. It really
does help. It's in everything you draw. You're going to have to draw them in perspective,
unless you're drawing abstract. But if you're taking these classes, you're probably not
drawing abstract. So focus on drawing angles and boxes and geometric primitives. It'll
really help you.
Final person, we're down to the very end, is Josip SilvOkami. So Josip, it looks like
you did something that actually I didn't assign but I should have. We were drawing the bucket
and the pelvis and how it fits inside the bucket, but we never really looked at how
it fits on a model, how it actually fits on a real body. So thank you for doing this so
I could point it out to you guys. However, it looks like you didn't position it inside
the body correctly. The main thing is you're drawing them just too small. The pelvis will
actually be on the surface of the body all the way around the sides, how the aces points
in the front actually protrude. And even on heavier people, that bony area of the iliac
crest will be very close to the surface. There will be some fat but usually above and below,
unless that person is very overweight, then everything is covered. But usually the iliac
crest will be very close to the surface, and so this distance that you're showing here
is just too much.
If you have a model and you just can't figure out where to put the bucket, there's a few
things you can look for, the landmarks, the bony parts that will be on the surface. Those
are very important. It's hard to tell from your rough drawing of the contours exactly
what position the model is in, but I'm just going to assume some things. For example,
the pubic bone will be somewhere in here, ileac crest will end right there-ish, at the
aces points and then right there on the other side. So I got this triangle shape, right?
I'm going to draw these points on the side here so I can draw a little bigger. So something
like this, that's generally the relationship between all these points. So you've got the
angle between the ASIS points, and then you got the pubic bone down here. So this is about
the triangle I'm seeing in your drawing.
Okay, now I'm going to take these landmarks and draw a bucket that fits on those
landmarks. So let's see, so I know that this pubic bone is going to be the edge of the
bucket. It sits at the very front. So I could draw the angle of that bucket, and I know
that the angle of the bucket is something like this. Okay. And then we know that the
aces points are going to be slightly forward from the center of the top cap, right? These
are not the middle. This is not the center line of the top. The center line will be slightly
back. And then I'm going to get a really rough shape in there, for where I think the bucket
would fit. So it's going to be a two dimensional shape, something like this. This helps me
to visualize that bucket. Very rough, I might deviate from that later once I get more points
in. Then I'm going to adjust this line real quick. It should go right through the pubic
bone, not in front of it. Okay, there you go.
So now I have to figure out the top cap, which is going to be at an angle about like this.
And it has connect these aces points, and it has to touch the front of the bucket and
the back. So basically, I'm just trying to find an ellipse that will connect that or
connect all those points, and that ellipse needs to be roughly that correct angle. That
long axis should be something like this. I can maybe taper this a little bit more now
that I have that top ellipse. It helps me realize that my initial shape was just a little
bit too flat, not flat but too parallel. The bottom needs to taper more.
Okay, so now I got the top cap. I got the sides, now let's find the bottom cap. And
that's going to be at the same angle. I've just got to find an ellipse. And let's see,
maybe this is a little bit too tall for a female pelvis, just a little bit. I'm going
to bring this up, because remember, a female pelvis is going to be a little bit wider and
shorter. So we're searching right now; we're exploring. We're not really sure exactly where
these lines are going to go. We're trying it out, analyzing it. If something is off,
we adjust and we slowly get closer and closer to the correct shapes. That looks about right
for that bottom cap.
Now, this point right here that I have, which is kind of like my center line
or my center point, it's not really the center so I have to make them adjustments to this.
Let's see, the center of that ellipse would be about there. So that's the center horizontal
or a center from side to side, and then front to back. Well, looks like if the pubic bone
is right there, the front is right about there. So if I just connect that to the middle, that's
the angle from front to back. You do the same thing for the bottom cap.
Okay, so that's pretty good for the bucket. I'm just going to cut out that wedge, just
take it one step further. So remember, the pubic bone is about halfway down. At this
point, I made it shorter. I made this bucket shorter to be a female pelvis, so I'm going
to just bring this pubic bone just a little bit higher. Our initial landmark was just
maybe a little bit off. Unless the female that you were drawing has a taller pelvis,
then that would have been correct.
And then from that center line, we could wrap a rubber band, so another ellipse around there,
a little bit lighter. And then from these aces points, we'll just drop verticals. That's
the step down. There's that edge between the front plane and the top plane. Okay, there's
a pretty good looking bucket. If I wanted to, I could put another layer over this and
clean up my lines a bit because they're messy, we were exploring, but I'll just leave it
at this. So hopefully that helps. Very good exercise. Thank you for showing that Josepp.
And that ends all the critiques. Whew! Thank you guys for submitting all your drawings.
I'm going to continue these critiques for the rest of the bone exercises. If you'd like
to submit your assignment for all the future lessons, go to proko.com/groups, and it'll
forward you to the Facebook groups that we are using right now. And there's a great community
out there, so join in, help each other learn, critique other people's work if you see a
mistake. Submit your work, people will critique you. Just keep the community going. I'm really
happy to see how much you guys are actually helping each other. It's been a great thing.
I'm really glad I started up that group. You guys were asking for it for quite a while.
All right, enough blabbering. See you next time.
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