ObJS

ObJS

A .obj files viewer for HTML5 written in JavaScript

Features

• Object rotation with the mouse.
• Zoom control with the mousewheel.
• Choose to draw (or not) vertizes, edges or faces.
• Change colors of background, vertizes, edges, and faces during runtime.
• Change face transparency during runtime, so hidden elements are visible.

How to use

Just include the ObJS.js in your project, create a ObJS object, and initalize its canvas.

myObJS = new ObJS();
myObJS.initCanvas(canvas);

Where

• canvas is the canvas element in witch the model will be represented. If this parameter is not specified, the script will try to use a canvas called ObJSCanvas.

Then you can load any obj model by calling

myObJS.load(file);

Where

• file is a character string with the path to the file, relative or absolute.

If you want to clear the canvas, just call

myObJS.clear();

Note that the canvas is automatically cleared when a new object is loaded.

Transformations

The model can be rotated and zoomed in and out with the mouse, but it can also be done programmatically.

To rotate the object, just call

myObJS.rotateX(ang); //Rotate along the X edge
myObJS.rotateY(ang); //Rotate along the Y edge

Where

• ang (integer) is not the exact angles to rotate, just a internal measure.

To zoom in or out the object, call the method

myObJS.zoom("+"); //Zoom in
myObJS.zoom("-"); //Zoom out

Customization

You can change parameters such as the elements to draw, their color, transparency, rotation speed, zoom speed... in the script, but much of them can be changed on runtime, so you can use controls.

Select which elements to draw

drawElement(keyword, on);

Where

• keyword is a character string indicating witch element you want or don't want to be drawn. Possible values are
  • 'backg', for the background.
  • 'verts', for the vertizes.
  • 'edges', for the edges.
  • 'faces', for the faces.
• on is a Boolean value, indicating if the element is to be drawn or not.

Select color for elements

colorElement(keyword, color);

Where

• keyword is a character string indicating witch element you want to colorize. Possible values are
  • 'backg', for the background.
  • 'verts', for the vertizes.
  • 'edges', for the edges.
  • 'faces', for the faces.
• color is a character string with the HEX codeo for the desired color, for example '#ff0000' for red.

Select face transparency

setAlpha(percent);

Where

• percent is an integer, between 0 and 100, indicating the level of transparency you want to apply to the faces.