This assignment is worth 15 points.
Unfortunately, it is difficult to load a file in javascript, so we need to convert these files to some format that can be placed on the web. While a json solution may be more elegant, you are to write a simple javascript solution.
You program should read in a .off file and produce a .js file. This file should construct an object. This object should have two properties, .triangles and .BC.
.triangles will return an array containing the triangles defining the object.
.BC returns the values required for barycentric shader. In the future, we will add another field, .normals which will return the computed normals associated with the vertex.
In the end, your program should produce a javascript file looking something like:
function CubeModel() {
this.triangles = [[-0.5, -0.5, -0.5], [0.5, -0.5, -0.5], ...]];
this.BC = [[1, 0, 0], [0, 1, 0] ...]];
};
And will be used like:
cube = new CubeModel();
console.log(cube.triangles);
console.log(cube.BC);
The off modes sometimes contain polygons that are not triangles, so your program should decompose all non-triangles into triangles.
While you have no control over how the polygons are specified (CW or CCW), make sure that you remain consistent with the original in your final output.
The Off models tend to be all over the place, so one additional requirement is that you scale the model so that it fits in the unit cube (-0.5, -0.5, -0.5) to (0.5, 0.5, 0.5). The ENTIRE model should be scaled by the largest dimension. So for example, if the model is bounded by the cube (1,1,1) to (9,10,11), the largest dimension is 11-1 or 10, so all coordinates should be scaled by 1/10.
Ideally the program should read the .off file from standard in and write the .js file to standard out. It should command line arguments for the name of the model to create. If you have had CSCI 311, you should do this. You may, however, write an interactive program that asks for
$ off2js Enter the input file name: cube.off Enter the output file name: cube.js Enter the model name: CubeModelIf you chose the CSCI 311 approach, your program should accept the command line option -modelName name. If no name is given, the default should be CubeModel.
$ off2js -modelName CubeModel < cube.off > cube.jsBy the way, please call your executable off2js.
More documentation on off files, along with links to multiple off file repositories are located here
You may use any language that will compile on the linux machines. I would assume C++. If you use c++, you may use the vector class.
Please be aware that lines in off files starting with a # are a comment.