Tracery Pattern: SketchBook or Journal

Assemble text and graphics into a single web page containing "figures" and "notes"

Subject Notes for Nov 12, 2010 [Add Content]

Diffuse Reflection

The underlying assumption behind lighting in most 3D modeling programs is that light reflects uniformly in all directions. This "diffuse reflection" means that we only need to care about the relationship between the surface and the light source--however the surface is illuminated, it is just as bright to viewers in any position. This contrasts with the "specular assumption". See also "cosine shading"

Cosine Shading (Lambert's law)

Incident light is spread out over a larger and larger area as theta increases from 0 to 90 degrees. Intuitively it should be brightest at 0 and dimmest at 90, suggesting the relationship shown in the equation, aka "Lambert's Law". This relationship is tightly tied to the assumption of perfectly diffuse reflection.


Sometimes you get both specular and diffuse reflections.

Figure Name?


Figure Name?

Figure Name?

Figure Name?

nice windws..

modified drawing

The change isn't terribly subtle. I hope it works.

Figure Name?

Flaming Goose

Had to think of a name. That's what came to mind.

About Tracery

Tracery makes graphic input available to web developers. To illustrate some of the ways it might be used, this site presents a "graphical bulletin board"--a place to draw and save graphics, but also a place to comment (verbally and graphically) on graphics already posted.

The image at far left is "hot" - click on it to access an interface through which you can draw or type your response to the graphic. Each image may have an associated comment, so you can offer comments on the image, or modifiy it, or both.

The thumbnails in the lower-left display the "family tree" for this discussion. Click any of the thumbnails to bring it "front and center".

Alternative Configurations

Home page
Sketchbook Sketching & Notes
SketchPad Shared serial sketching
Assignment Prompt & Response
CoQuilt Collaborative design

In Progress...
Homework submittal and grading

Usage Tips:

  • click on the "img" graphic to open a Markup Panel
  • change line weight or color using the menu in the lower-left corner of the drawing area.
  • click on the "Derivations" link below to view previous responses, or scroll down (you may need to refresh if something has been saved since this page was loaded).
  • If the display window is smaller than the actual image, you can use command+Click & drag to pan large drawings.
View Derivations (aka Drawing History)

November, 2010
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Base images

Figure Notes:

If you've selected an existing figure to add to or draw over, here is what you wrote at the time you created that figure.

plain Grid
You can use this base drawing for most scaled illustrations where guidelines might matter. Remember, you can always save the results without the background if that looks better.