I eventually completed the second physics material addition to Trajec3D - it turned out a bit more challenging that I anticipated. But, the addition of a third or fourth physics materials is now trivial (only time consuming) if we decide to pursue that - let me know your thoughts. I kept the expiry date at 1 April 2013, as we could find a bug or two with the latest version due to the substantial changes to the code base.
Careful consideration was given to the implementation of the second physics material, as I want keep the current simplicity of Trajec3D. A button was added to the top toolbar, but can be ignored and Trajec3D then functions exactly as before - see the new second button from the left.
The logic of the method I selected for the second physics material is that sub-horizontal surfaces are typically softer than sub-vertical surfaces. The sub-horizontal surfaces often consist of broken material, and the sub-vertical surfaces of clean rock surfaces. The sub-horizontal surfaces thus typically have lower rebound (Coefficient of Restitution) and higher friction angles, as fall bodies have to plough through the broken material on the sub-horizontal surfaces.
If the second physics material is required, follow the following procedure:
Load a file, or build a custom slope, as before with the first "Mat1"-button. This will create the first physics material in a bronze colour that can be used as before.
Press the second (new) button and select the only option "Split triangulation on dip angles". This is currently the only option, with more options the follow in future.
A form will be displayed with a few options as shown below the dot points. The first is the angle from horizontal for the second physics material, and the rest the physics properties of the second material.
Accepting the parameters on the form will divide the pit into two colours with different physics materials.
The bronze colour is Mat1, and the physics properties selected with the tabs on the left lower bottom as before. The light blue colour is Mat2 that is given the properties of the form (image to the left) that pop-up when selecting "Split triangulation on dip angles".
The cut-off angle for the second material is basically the angle from horizontal that will still serve as catchment, and the bi-coloured triangulation also provide a visual indication of the catchment capacity of the benches (see figure below). This is similar to the functionality added to GEM4D discussed in the previous post.