Enabling Selective Surface-Based Collision

// AppWorldLogic.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Unigine;

namespace UnigineApp
{
	class AppWorldLogic : WorldLogic
	{

        ObjectMeshStatic box1;
        ObjectMeshStatic box2;
        ObjectMeshStatic plane;
		PlayerSpectator player;

        /// method, creating a named box of a specified size and color at pos
        ObjectMeshStatic create_box(String name, vec4 color, vec3 size, vec3 pos)
        {
	        // creating an auxiliary mesh with a box surface
	        Mesh meshbox = new Mesh();
	        meshbox.AddBoxSurface("box_surface", size);

	        // creating a static mesh object using an auxiliary mesh and setting parameters
	        ObjectMeshStatic OM = new ObjectMeshStatic(meshbox);

	        OM.WorldTransform = new dmat4(MathLib.Translate(pos));
	        OM.SetMaterialParameterFloat4("albedo_color", color, 0);
			OM.SetCollision(1, 0);
	        OM.Name = name;

	        // assigning a rigid body with our object
	        new BodyRigid(OM);
	
	        // creating a box shape and assigning it to the rigid body of our object
	        OM.Body.AddShape(new ShapeBox(size), MathLib.Translate(0.0f, 0.0f, 0.0f));
	
	        // clearing the auxiliary mesh
	        meshbox.Clear();

	        return OM;
        }

        /// method, creating a named plane having a specified width and height at pos
        ObjectMeshStatic create_plane(String name, float width, float height, vec3 pos)
        {
	        // creating an auxiliary mesh with a plane surface
	        Mesh meshplane = new Mesh();

	        meshplane.AddPlaneSurface("plane_surface", width, height, 1.0f);

        	// creating a static mesh object using an auxiliary mesh and setting parameters
	        ObjectMeshStatic OM = new ObjectMeshStatic(meshplane);

	        OM.WorldTransform = new dmat4(MathLib.Translate(pos));
	        OM.SetMaterialParameterFloat4("albedo_color", new vec4(0.0f, 0.0f, 1.0f, 1.0f), 0);
			OM.SetCollision(1, 0);
	        OM.Name = name;

	        // clearing the auxiliary mesh
	        meshplane.Clear();

	        return OM;
        }
		
		/* .. */
		
		public override bool Init()
		{
		
            // setting up a player
	        player = new PlayerSpectator();
	        player.Position = new dvec3(0.0f, -6.0f, 12.5f);
	        player.SetDirection(new vec3(0.0f, 1.0f, -0.4f), new vec3(0.0f, 0.0f, -1.0f));
	        Game.Player = player;

	        // creating a scene: two boxes and a plane
	        box1 = create_box("box1", new vec4(1.0f, 1.0f, 0.0f, 1.0f), new vec3(0.5f), new vec3(1.5f, 0.0f, 12.0f));
	        box2 = create_box("box2", new vec4(1.0f, 0.5f, 0.1f, 1.0f), new vec3(0.5f), new vec3(-1.5f, 0.0f, 12.0f));
	        plane = create_plane("plane", 10.0f, 6.0f, new vec3(0.0f, 1.0f, 10.5f));

	        // setting shape collision mask for the first box  [00000000000000000000000000000010]
	        box1.Body.GetShape(0).CollisionMask = 2;

	        // setting shape collision mask for the second box  [00000000000000000000000000000001]
	        box2.Body.GetShape(0).CollisionMask = 1;

	        // setting collision mask for the plane surface  [00000000000000000000000000000010]
	        plane.SetCollisionMask(2, 0);

			return true;
		}
		
		/* .. */
		
	}
}