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Rebeccak
02-13-2007, 09:59 PM
TUTORIAL / Exercise - Cross Contour Drawing


Some folks have asked me about the recent cross contour drawings which I have been doing for a drawing class I have been sitting in on. It's a college level drawing class with an excellent professor, Chawy Frenn (http://chawkyfrenn.com/), who is great at getting his students to perceive in different ways and to learn how to speak about and critique their own and others' work - essentially, to become visually literate.

It's the first drawing class I've taken in years, so though the exercises are very basic and fundamental, I've found the course to be so refreshing and is helping me to connect some of the missing dots in my own drawings. I hope this tutorial is useful. :) Please note that my comments here on cross contour drawings are mainly derived from the teaching of Professor Chawky Frenn.

Thank you to mashru (http://mashru.cgsociety.org/gallery/) for allowing me to use his free downloadable female 3D model for illustrative screenshots. Mashru's model (obj. file) may be downloaded for free here:

Free Model (http://forums.cgsociety.org/showthread.php?t=446213)
http://forums.cgsociety.org/showthread.php?t=446213

+++

What is a cross contour Drawing?

A cross contour drawing may be thought of as a topological map of the face and body, or of whatever form you are drawing. Cross contour lines may be thought of as vertical and horizontal slices of the figure (or as in the case of 3D - wireframes).

The purpose of a cross contour drawing is to allow the student the opportunity to draw not just the outline of the figure, but to map the interior of the form. As you are drawing, you are to look more at the model than at the page. You should also think of yourself as an ant along the surface, mapping the surface of the form with your eyes and transcribing it onto the page.

Elements of a cross contour Drawing

Perspective and where the viewer is in relation to the model is of primary importance in a cross contour drawing.

Here are some screen shots of some simple primitive shapes as seen from different positions. There is a deformed sphere, a sphere, a cylinder, and a cube. The wireframes - the horizontal and vertical lines - of the primitives are essentially the cross contours of the objects.

Notice how as the viewer's position changes, the direction of these wireframe lines / cross contour lines change. Depending on the eye level of the viewer, the lines will either curve up (if the object is seen from below) or curve down (if the object is seen from above) in accorance with the laws of perspective.

Notice that the eye level of the viewer is level with the center of the objects in this first example. Note how the horizontal lines above the viewer's eye level curve upward, and the horizontal lines below the viewer's eye level curve downward. Also notice how the horizontal and vertical lines are spaced depending on how close to the viewer they are. The spacing between the lines becomes much less - the lines become closer together - as the object recedes in space:

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour-shots_001.jpg

Now the viewer's eye level is below all of the objects. Note how the horiz. lines all curve upward and around the rounded objects. Notice how the spacing between the lines is greater where the object most protrudes and is closest to the viewer, and how the spacing becomes less as the object recedes in space:


http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour-shots_002.jpg

Here the viwer's eye level is above the objects. Notice how the horiz. lines of the rounded objects curve downward and wrap around the form. Again, take note of the line spacing depending on how close or far the object is fromt the viewer:



http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour-shots_003.jpg

Here the viwer's position is slightly above the objects and to the left. Notice how the horiz. lines of the rounded objects curve downward and wrap around the form, but less dramatically than when the viewer's eye level was higher. Again, take note of the line spacing depending on how close or far the object is fromt the viewer:

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour-shots_004.jpg

Notice how dramatically the curves are affected by the higher eye level of the viewer relative to the objects below:


http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour-shots_005.jpg

Rebeccak
02-13-2007, 10:15 PM
*Please note that the 3D female figure is by mashru.

Taking the above simple examples further, let's look at a 3D model of a head and figure (as generously provided for free by mashru (http://forums.cgsociety.org/showthread.php?t=446213)).

Below I've taken mashru's model and screencaptured it and a cylinder with a proximal position in space from varying perspectives to illustrate the cross contour lines of each in space.

In each of the images below, look at the horizontal lines to analyze how they curve either upward or downward depending on where the eye level of the viewer is relative to the figure and the cylinder.

Also, analyze the spacing of the horizontal lines relative to one another and the vertical lines relative to one another to see how the spacing grows or shrinks depending on whether the form is extending or receding into space.

Finally notice how these horizontal and vertical lines literally map the surface of the form - the images below are 2D screen captures, yet because the horizontal and vertical lines follow the topology of the form, they create the illusion of dimensionality. This is the goal of a cross contour drawing:

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_001.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_002.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_003.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_004.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_005.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_006.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_007.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body-Cyl_008.jpg

Rebeccak
02-13-2007, 10:44 PM
Now look at and analyze these screencaptures of the model alone and analyze the form based on horizontal and vertical line proximity and direction (upward curving or downward curving) of the horizontal and vertical lines. Ask yourself, how are these lines creating the illusion of form and dimensionality?

Note how the horizontal lines above the viewer's eye level curve upward, and those below curve downward.

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body_001.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body_002.jpg

Note that there are no downward curving lines here, because the viewer's eye level is below the entire figure:


http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body_003.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Body_004.jpg

Rebeccak
02-13-2007, 10:51 PM
The above images are meant only to illustrate the concepts of perspective that are crucial for an understanding of a cross contour drawing. This is not a 3D tutorial, but a 2D drawing tutorial which is meant to help you to describe 3Dimensional form on the page.

Elements of a cross contour Drawing

There are a number of different formal visual elements which are important in a cross contour drawing:

Line weight / pressure / contrast of lines

Line spacing / proximity

Line direction

Line weight and contrast comes into play especially - a lighter line recedes, while a thicker / heavier line comes forward in space.

Line spacing, as we have seen illustrated above, determines how close to the viewer a particular area of the object is - the nose, for example, protrudes further from the face than the lips in a front view, so the line spacing would be greater on those areas of the nose closest to the viewer. By contrast, where the cheeks begin to recede back toward the ears and edges of the face, the cross contour lines would be spaced more closely together to indicate their recession.

Line direction (upward facing or downward facing lines) determines how the viewer's eye level is shown - lines above the viewer's eye level with curve upward, while lines below the viewer's eye level will curve downward.

Rebeccak
02-13-2007, 10:56 PM
And now, for the embarrassing part - some self portraits / cross contour drawings done for my class. These drawings are far from perfect, but I hope that they are illustrative of the concepts described above and I highly encourage you to try them.

The main thing I recommend is to draw from life when doing these. The assignment I had is to do around 8 of these cross contour drawings in a week. Doing this exercise, as fundamental as it is, has really helped me to perceive things better and to look more closely at the subject at hand, as well as to better analyze it.

30 minute contour drawings:

http://anatomy.cgnetworks.com/15%20Minute%20Sketch/Sketchathon-011.jpg

http://anatomy.cgnetworks.com/15%20Minute%20Sketch/Sketchathon-014.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Drawing-003.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Drawing-002.jpg

After doing these ballpoint pen cross contour drawings initially, I decided to try and incorporate the cross contour drawing concept into my charcoal drawings, which I believe has made a difference. These are drawn from reference:

Untimed:

http://www.rebeccakimmel.com/gallery/albums/Traditional-Drawings/_Charcoal-Drawings_9991.jpg

30 minutes:


http://www.rebeccakimmel.com/gallery/albums/Traditional-Drawings/Sketchathon-016.jpg

30 minutes:


http://www.rebeccakimmel.com/gallery/albums/Traditional-Drawings/Sketchathon-017.jpg

Rebeccak
02-13-2007, 11:04 PM
Finally, here are some more screen captures of the head model by mashru (http://forums.cgsociety.org/showthread.php?t=446213) to further illustrate the cross contour lines of the head.

One thing to note about the difference between the wireframe of the model used and drawing cross contour lines is that mashru has modeled the figure to be animated, so the wireframe topology is a bit different in some places than how you want to draw your cross contour drawing.

When drawing, think of each line as a slice of the figure - don't encircle areas (such as the mouth) which is something in the 3D model which is done to make it better to animate - instead in your drawings, make the lines continuously either horizontal or vertical, but following the topology of the form - sort of as though you are skiiing over it in either direction.

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_001.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_002.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_003.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_004.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_005.jpg

Rebeccak
02-13-2007, 11:04 PM
http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_006.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_007.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_008.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_009.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_010.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_011.jpg

http://www.rebeccakimmel.com/gallery/albums/Cross%20Contour%20Tutorial/Cross-Contour_Face_012.jpg

Rebeccak
02-13-2007, 11:07 PM
Cross Contour Drawing Exercise

I really recommend trying this exercise for those who haven't, or for those who haven't for years. ;)
Working from life only, draw at least 5 - 10 timed cross contour drawings of a head / face - your own or of someone you know. Do at least 5 in one week.

Use 4B or 6B sharpened pencil in a sketchbook which is at least 12" x 12" in dimension.

If you time your cross contour drawings, give yourself 30 minutes for each.

*Note that the 3D illustrations are just that - illustrations - this is a 2D Drawing Exercise.

I hope this is useful. Please feel free to post your work here! :)

Cheers,

-Rebeccak

anandpg
02-14-2007, 04:50 AM
Hi Rebecca!.. This is really helpful! thanks.:) I will try and draw from 3d Models(I dont have access to live models right now) to post here.

Rebeccak
02-14-2007, 02:18 PM
Thanks anand! :) Actually I really recommend doing self portraits - though I've tried the method using Sketchathon reference, and that is helpful as well, I think you'll most definitely get a stronger drawing using yourself as reference or a friend.

Thanks for your reply! :)

Sketchathon reference is here (http://forums.cgsociety.org/showthread.php?p=4191662#post4191662) (NUDITY):

http://forums.cgsociety.org/showthread.php?p=4191662#post4191662

Miyagu
03-04-2007, 04:29 PM
Lovely drawings Rebecca! Inspiring to look at.. really "fleshy"..

paintdabs
03-06-2007, 09:33 PM
Hi Rebecca, I'm finally checking out the forums, etc here and came across yours. I have a lot of baby steps to take, but am inspired and edified by all the terrific artists here.

Rebeccak
03-06-2007, 09:50 PM
Benita, you changed your name! Thanks for stopping by. :)

Dorothy, good to see you on the boards, and look forward to seeing your participation around here! Feel free to start up a Sketchbook in the Sketchbook area, would be nice to see your work. :)

su
07-06-2007, 03:16 AM
Thank you Rebecca for the tutorial and Mashru for the model used in the illustrations :)

That seems to be a pretty good exercise, and it would also be helpful to draw with contours if you are going to shade your drawing.

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