This second step model adds the moving3D skill to the cell agents and simply makes the cell agents move by defining a reflex that will call the action move. We will also add additional visual information to the display.

• Redefining the shape of the world with a 3D Shape.
• Attaching new skills (moving3D) to cell agents.
• Modify cell aspect.
• Add a graphics layer.

We use a new global variable called environment_size to define the size of our 3D environment. In the global section, we define the new variable:

int environment_size <-100;

Then we redefine the shape of the world (by default the shape of the world is a 100x100 square) as a cube that will have the size defined by the environment_size variable. To do so we change the shape of the world in the global section:

geometry shape <- cube(environment_size);	

When we created the cell agents, we want to place them randomly in the 3D environment. To do so we set the location with a random value for x, y and z between 0 and environment_size.

create cell number: nb_cells { 
  location <- {rnd(environment_size), rnd(environment_size), rnd(environment_size)};       
}

In the previous example, we only created cell agents that did not have any behavior. In this step we want to make them move. To do so we add a moving3D skill to the cell species.

More information on built-in skills proposed by GAMA can be found here.

species cell skills: [moving3D]{
...  	
}

Then we define a new reflex for the species cell that consists in calling the action move bundled in moving3D skill.

reflex move {
    do move;
}	                    

Finally we modify a bit the aspect of the sphere to set its size according to the environment_size global variable previously defined.

aspect default {
    draw sphere(environment_size*0.01) color: #blue;   
}

The experiment is the same as the previous one except that we will display the bounds of the environment by using a graphics layer.

graphics "env" {
    draw cube(environment_size) color: #black wireframe: true;	
}

output {
    display View1 type:opengl{
        graphics "env"{
            draw cube(environment_size) color: #black wireframe: true;	
        }
        species cell;  
    }
}

https://github.com/gama-platform/gama.old/blob/GAMA_1.9.2/msi.gama.models/models/Tutorials/3D/models/Model%2002.gaml