Add generic joint support to physics extension

gama.extension.physics/models/Physics Engine/models/Box2D Articulated Arm.gaml

@@ -0,0 +1,59 @@
+/**
+ * A two-link robotic arm driven by Box2D revolute-joint motors.
+ */
+model Box2D_Articulated_Arm
+
+global parent: physical_world {
+	string library <- "box2D";
+	float step <- 1.0 / 60;
+	int world_width <- 200;
+	int world_height <- 100;
+	geometry shape <- rectangle(world_width, world_height);
+	point gravity <- {0, 0, 0};
+	joint shoulder_joint <- nil;
+	joint elbow_joint <- nil;
+
+	init {
+		create arm_base {
+			location <- {45, 50};
+		}
+		create arm_link number: 2 {
+			location <- index = 0 ? {75, 50} : {125, 50};
+		}
+
+		shoulder_joint <- create_hinge_joint(arm_base[0], arm_link[0], {50, 50}, -1.2, 1.2, 0.0, 80.0);
+		elbow_joint <- create_hinge_joint(arm_link[0], arm_link[1], {100, 50}, -1.2, 1.2, 0.0, 45.0);
+	}
+
+	reflex drive_arm {
+		shoulder_joint.motorSpeed <- 1.5 * sin(cycle * 3);
+		elbow_joint.motorSpeed <- 2.0 * sin(cycle * 3 + 90);
+	}
+}
+
+species arm_base skills: [static_body] {
+	geometry shape <- box(10, 14, 0.1);
+
+	aspect default {
+		draw shape color: #darkgray;
+	}
+}
+
+species arm_link skills: [dynamic_body] {
+	geometry shape <- box(50, 8, 0.1);
+	float mass <- 2.0;
+	float friction <- 0.5;
+
+	aspect default {
+		draw shape color: #steelblue rotate: float(rotation.key);
+	}
+}
+
+experiment "Box2D Articulated Arm" type: gui {
+	output {
+		display Arm type: 2d axes: false {
+			species arm_base;
+			species arm_link;
+		}
+	}
+}

gama.extension.physics/models/Physics Engine/models/Box2D Wheel Car.gaml

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+/**
+ * A car whose wheels are Box2D wheel joints (suspension + motor), followed by a trailer
+ * attached with a rope joint and a hanging load attached with a distance (spring) joint.
+ */
+model Box2D_Wheel_Car
+
+global parent: physical_world {
+	string library <- "box2D";
+	float step <- 1.0 / 60;
+	int world_width <- 300;
+	int world_height <- 100;
+	geometry shape <- rectangle(world_width, world_height);
+	point gravity <- {0, -9.81, 0};
+	list<joint> motors <- [];
+
+	init {
+		create ground {
+			location <- {150, 5};
+		}
+		create chassis {
+			location <- {40, 25};
+		}
+		create wheel number: 2 {
+			location <- index = 0 ? {30, 17} : {50, 17};
+		}
+		loop i from: 0 to: 1 {
+			point anchor <- wheel[i].location;
+			motors << create_wheel_joint(chassis[0], wheel[i], anchor, {0, 1, 0}, 4.0, 0.7, -8.0, 200.0);
+		}
+		create trailer {
+			location <- {10, 25};
+		}
+		joint tow <- create_rope_joint(chassis[0], trailer[0], {32, 25}, {16, 25}, 12.0);
+		create load {
+			location <- {40, 40};
+		}
+		joint spring <- create_distance_joint(chassis[0], load[0], {40, 28}, {40, 38}, 2.0, 0.3);
+	}
+
+	reflex report when: every(60 #cycle) {
+		write "wheel translation: " + motors[0].translation with_precision 2;
+	}
+}
+
+species ground skills: [static_body] {
+	geometry shape <- box(300, 10, 0.1);
+
+	aspect default {
+		draw shape color: #gray;
+	}
+}
+
+species chassis skills: [dynamic_body] {
+	geometry shape <- box(30, 6, 0.1);
+	float mass <- 5.0;
+
+	aspect default {
+		draw shape color: #firebrick rotate: float(rotation.key);
+	}
+}
+
+species wheel skills: [dynamic_body] {
+	geometry shape <- circle(5);
+	float mass <- 1.0;
+	float friction <- 1.0;
+
+	aspect default {
+		draw shape color: #black;
+	}
+}
+
+species trailer skills: [dynamic_body] {
+	geometry shape <- box(14, 4, 0.1);
+	float mass <- 1.0;
+
+	aspect default {
+		draw shape color: #steelblue rotate: float(rotation.key);
+	}
+}
+
+species load skills: [dynamic_body] {
+	geometry shape <- circle(2);
+	float mass <- 0.5;
+
+	aspect default {
+		draw shape color: #gold;
+	}
+}
+
+experiment "Box2D Wheel Car" type: gui {
+	output {
+		display Car type: 2d axes: false {
+			species ground;
+			species chassis;
+			species wheel;
+			species trailer;
+			species load;
+		}
+	}
+}

gama.extension.physics/models/Physics Engine/models/Bullet Cone-Twist Tentacle.gaml

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+/**
+ * A tentacle made of boxes linked by cone-twist joints (ragdoll-style), anchored to a fixed base
+ * with a fixed joint, and swung around by an initial push. Runs on native Bullet when available.
+ */
+model Bullet_ConeTwist_Tentacle
+
+global parent: physical_world {
+	string library <- "bullet";
+	bool use_native <- true;
+	int segment_count <- 8;
+	float segment_length <- 10.0;
+	geometry shape <- box(160, 80, 80);
+	point gravity <- {0, 0, -9.81};
+
+	init {
+		do register([self]);
+		create tentacle_base {
+			location <- {30, 40, 60};
+		}
+		create tentacle_segment number: segment_count;
+		ask tentacle_segment {
+			location <- {30 + (index + 1) * segment_length, 40, 60};
+		}
+		joint root <- create_fixed_joint(tentacle_base[0], tentacle_segment[0], {30 + segment_length / 2, 40, 60});
+		loop i from: 0 to: segment_count - 2 {
+			point anchor <- {30 + (i + 1.5) * segment_length, 40, 60};
+			joint j <- create_cone_twist_joint(tentacle_segment[i], tentacle_segment[i + 1], anchor, {1, 0, 0}, 0.5, 0.3);
+		}
+	}
+}
+
+species tentacle_base skills: [static_body] {
+	geometry shape <- box(10, 10, 10);
+
+	aspect default {
+		draw shape color: #darkgray;
+	}
+}
+
+species tentacle_segment skills: [dynamic_body] {
+	geometry shape <- box(10, 4, 4);
+	float mass <- 0.5;
+	float friction <- 0.4;
+
+	aspect default {
+		draw shape color: rgb(255, 120 + index * 15, 60) rotate: float(rotation.key);
+	}
+}
+
+experiment Tentacle type: gui {
+	output {
+		display Tentacle type: 3d {
+			graphics "World" {
+				draw shape color: #white wireframe: true;
+			}
+			species tentacle_base;
+			species tentacle_segment;
+		}
+	}
+}

gama.extension.physics/models/Physics Engine/models/Jointed Snake.gaml

@@ -0,0 +1,54 @@
+/**
+ * A simple articulated chain driven by hinge motors.
+ */
+model Jointed_Snake
+
+global parent: physical_world {
+	string library <- "bullet";
+	bool use_native <- true;
+	int segment_count <- 8;
+	float segment_length <- 16.0;
+	list<joint> joints <- [];
+	geometry shape <- box(160, 80, 40);
+	point gravity <- {0, 0, 0};
+
+	init {
+		do register([self]);
+		create snake_segment number: segment_count;
+		ask snake_segment {
+			location <- {30 + index * segment_length, 40, 20};
+		}
+		loop i from: 0 to: segment_count - 2 {
+			point anchor <- {30 + (i + 1) * segment_length - segment_length / 2, 40, 20};
+			joints << create_hinge_joint_with_axis(snake_segment[i], snake_segment[i + 1], anchor, {0, 0, 1},
+					-0.6, 0.6, 0.0, 8.0);
+		}
+	}
+
+	reflex drive_joints {
+		loop i from: 0 to: length(joints) - 1 {
+			joints[i].motorSpeed <- 1.2 * sin(cycle * 8 + i * 45);
+		}
+	}
+}
+
+species snake_segment skills: [dynamic_body] {
+	geometry shape <- box(16, 5, 5);
+	float mass <- 1.0;
+	float friction <- 0.4;
+
+	aspect default {
+		draw shape color: #orange rotate: float(rotation.key);
+	}
+}
+
+experiment Snake type: gui {
+	output {
+		display Snake type: 3d {
+			graphics "World" {
+				draw shape color: #white;
+			}
+			species snake_segment;
+		}
+	}
+}