Overview

3-mode 3D triangular facet renderer written in Clojure. The viewpoint is rendered with orthographic projection in the positive Z direction. The origin is centered, X increases rightwards, and Y increases upwards. Backface culling is enabled in all modes. Input takes the form of TRI files specified by path on the command line. In some modes, keyboard control provides rotation and scaling of the mesh about the origin.

Usage

Modes

Mode must be specified at command line:

• bary2: Triangles are rendered in color with barycentric interpolation.
• wire: Front-facing triangles are rendered solely as their edges, in white.
• shade: Directional lighting (from an arbitrary, hardcoded direction) is used for flat shading of triangle faces. Colors are shaded linearly from full color on light-source-facing triangles to black on triangles facing along the source's vector. Barycentric interpolation is still used for coloring.

Shade and bary2 are the slowest modes, due to rendering each triangle pixel by pixel. Wire is much faster. All are rendered against a black background.

Interaction

The left and right arrow keys change rotation around the Y (vertical) axis and the up and down arrow keys change rotation around the X (horizontal) axis. Each increments or decrements rotation by 0.1 radians. To compute the current scene, the accumulated X rotation is applied before the Y rotation. The [r] key resets both rotations to 0 radians.

The object may be scaled up by a factor of 1.1 using the [+] key and down by the same factor using the [-] key. Scaling is reset to 1 using the [1] key.

Compilation

timmcHW4 requires a GNU/Linux machine with Java on the classpath.

On first run, the Leiningen build tool will be downloaded into the project directory and will install its dependencies into the ~/.lein directory. Compilation is JIT and will occur during the first run.

Execution

Invoke ./run.sh mode filename to execute HW4.

Known bugs

• Neither z-buffer nor the painter's algorithm are implemented, so non-convex obects may not render properly in certain orientations.

Extra credit

Possible items:

• Light direction is arbitrary, though currently hardcoded as having a source in the upper right foreground. Lighting intensity goes to zero at back, not side, relative to source.

Third-party credit

• No external source code was incorporated into this project.
• Libraries used: Incanter (for matrices), Clojure, and Java standard libraries