CIS 781: Introduction to 3D Image Generation

Autumn 1998; Instructor: Rick Parent

[[ NOTE: The cooler stuff is at the BOTTOM of this page, in the more complex labs ]]

LAB1 - Wireframe rendering, 3D transformations, Polygon Clipping, &tc

Remember that teapot, you'll see it again a few times below.
It's the classic 'Utah Teapot', a historical object in computer graphics.

LAB2 - Polygon scan conversion, Basic Illumination model

Objects here are flat shaded, IE a single color is used across an entire face of an object. The images below are compressed much more than they should be, and have had the colors brightened (after they were compressed, bad move, Vince).

Note that the last image contains a spot light. The face shading causes an interesting effect as some faces are inside or outside the light's beam.

LAB3 - Complex lighting model, Solid modeling (3D texture).

Gouraund and Phong smooth shading are implemented. Note how objects appear smooth compared to the flat looking pictures from lab2. A side by side example of Gouraund, Face, and Phong can be seen respectively in the middle picture with all the boxes. Notice how Phong shows a 'hot spot' or bright point where the light source is reflected. Gouraund misses this, but does vary the color along the face. Face shading is just a flat color across the entire side.

The last four mushrooms have solid modeling functions which changes the color along the surface.

LAB4 - Raytracer.

Objects are all spheres (I will add more object types later). Reflection and Refraction are done easily with a raytracer, however it takes a long time to generate the images. A 'long time' can range anywhere from a few seconds up to a few days. Images below with thousands of spheres that are all reflective and refractive a 'long time' is often many hours.

These images all use many spheres, which would have been impractical to place by hand. Instead I 'painted' them in: I made two grayscale images and used the brightness at each point to specify the height and radius of a sphere.

This image contains 101 spheres, all reflective, one refractive. It took 10 minutes or so to render on my Pentium 133.

Detail of a portion of the previous image.

This image contains over 10,000 spheres!

This image has over 20,000 spheres. ALL are reflective and 10,000 are refractive.

A variation on the previous (20,000+ spheres). No post proccessing or color alteration was done, this is the exact output of the raytracer.