The Moon is a Marble

Discourses Relating to Art and Science

Thursday, September 30, 2010


Warm up dice

Do you ever sit down to sketch, but you don't know what to draw?  I have been working on drawing faces and heads lately using the Andrew Loomis method for head construction and I  wanted a good way to challenge myself and my friends.  I finally figured out how to draw the head facing in any orientation, so I was thinking about a way to randomize a view to get me to practice.  At the same time, a friend of mine showed me Scott McCloud’s 6 basic emotions and 36 compound expressions, from Making Comics, p. 85. He argues that there are 6 basic emotions that can be combined to show the range of human expression.

So, I came up with Warm-up Dice to generate both a random face orientation and expression for a pose. You can play with regular dice, or make your own with blank dice.  Roll a six-sided die five times.  Three times for position, twice for emotion.  Click here for a roll.
On the first roll:
  • 1-2 = Low angle
  • 3-4 = Nothing
  • 5-6 = High angle
On the second roll:
  • 1-2 = Left
  • 3-4 = Nothing
  • 5-6 = Right
On the third roll:
  • 1-3 = Front
  • 4-6 = Nothing
For example, if the roll is [Low, Left, Front] then the head position is a low angle shot so you are looking up at the character, from the left and front (I use my left rather than the character’s left). If it comes up [__, Left, Front] then it is a level shot, 3/4 view.   [__, __, Front] would be a nice, easy front view.   [Low, Left, __] would be a side view.

For the emotions, the fourth and fifth roll are the same:
  • 1 = Anger
  • 2 = Disgust
  • 3 = Fear
  • 4 = Joy
  • 5 = Sadness
  • 6 = Surprise
Add the two emotions together as in Scott McCloud, Making Comics.  Fear + Sadness = devastation.  Anger + Disgust = outrage, etc.

Table pinched from the summary here.

There you go.  Start sketching!

Other options
Add a face
This method of randomization seems particularly suited to people who want to be sure that they can draw a particular character in any pose.  Animators and comic artists will already have a character in mind.
If you need a face for your sketch, try these options:
IMDB’s fresh faces gallery
This skews toward pretty and young faces, and there is no convenient link.  The faces refresh every week.  Or, use the Whose Birthday is Today feature on the front page.
They have portrait photos.  Hit shuffle.  The content seemed very pretty-girl-heavy.
Or, I just grabbed a magazine from the rack at the coffee shop where I was and used the girl on the cover, Lea Michele, ever heard of her?

If the position roll comes up [ ___, ___, ___ ] then re-roll.  [ High, ___, ___ ] and [ Low, ___, ___ ] are also re-rolls, because they would just be top or bottom views.

If the same emotion is rolled twice, then roll again for the intensity of the emotion   Joy + Joy = roll again.  I use a 4-sided die to match the intensities in Making Comics, p. 84.  1 = heh, 2 = lol, 4 = omgroflmao.

Other sketch idea generators
Paul Greveson’s SpeedPaint script:
Paul’s script has characters, scenarios, vehicles and structures.  I usually reserve the option to delete one of the descriptors, maybe I am satisfied with a “wrinkled, small troll” and don’t need a “wrinkled, small troll with wheels,” okay?

Andrew Bosley’s brainstormer:
Includes a ‘story conflict’ section, some kickass adjectives and (..clicks ‘random’..) Tim Burton-ish nouns.
Grab the old game of Pictionary and draw a card from the deck, pick the item that you like best and think of the most clever way to show it. It is a different sort of experience when the 1 minute timer isn't dropping sand.


Saturday, September 18, 2010


How to align a centrolinead

How to align a Centrolinead

James Gurney and Craig Elliot had posts about this tool from the by-gone days of board-drawing.  The centrolinead is a sort of adjustable T-square ruler that you can use to make tapered perspective lines to a vanishing point that may be dozens of feet off of the edge of the paper.

from, Mathematical Instruments: Drawing and measuring instruments, John Fry Heather, p. 10

How does it work?
The geometry of the Centrolinead is based on the Inscribed Angle Theorem.  A proof of the method can be found in the volume excerpted below, Geometry, plane, solid, and spherical, in six books, whose subtitle rambles to include, to which is added, in an appendix, the theory of projection, so far as it is auxiliary to geometry; with an account of the Plane sections of the cone and cylinder, in which certain general properties of the conic sections are demonstrated by help of the foregoing theory.

The proof.  (It is okay to skip this part)

This is fine and edifying reading material, to be sure, but the main idea is that four points remain on the line that describes a fixed circle:  the vanishing point, the two studs, and the intersection of the ruler's edges (the edges that slide on the studs).

How do you set the centrolinead to line up with your vanishing point?

I found several sources that simply say, "Adjust the centrolinead by trial and error."  If that answer is sufficient for you, good day to you and happy drawing!

If not, here is one explanation, including an example.  Note that they expect you to know the measurement of the distance between the studs and your vanishing point.  Start at "To set the centrolinead..."

A numerical method for setting your centrolinead
from, Mathematical Instruments: Drawing and measuring instruments, John Fry Heather, p. 10

Unless you are a master draftsman, you may not know precisely where your vanishing point is.  If you just have an existing line, and a pre-existing horizon, you can use this method:

Setting the ruler using a pre-existing line
from, Mathematical Instruments: Drawing and measuring instruments, John Fry Heather, p. 10-11

Finally, there is this method of setting the centrolinead first, and then varying where the second pin goes:

Setting the centrolinead first and then putting the lines in

A Descriptive Treatise on Mathematical Drawing Instruments, William Ford Stanley, p. 171

And if all these things don't work or don't make sense, you can always just work at a really long table, with a really long ruler.



February 2009   January 2010   September 2010   October 2010  

This page is powered by Blogger. Isn't yours?

Subscribe to Posts [Atom]