BGE patch #28476: Character object physics type

===============================================
This patch adds a new "Character" BGE physics type which uses Bullet's btKinematicCharacter for simulation instead of full-blown dynamics. It is appropiate for (player-controlled) characters, for which the other physics types often result unexpected results (bouncing off walls, sliding etc.) and for which simple kinematics offers much more precision.

"Character" can be chosen like any other physics type in the "Physics" section of the properties window. Current settings for tweaking are "Step Height" (to make the object automatically climb small steps if it collides with them), "Fall Speed" (the maximum speed that the object can have when falling) and "Jump Speed", which is currently not used.

See http://projects.blender.org/tracker/?func=detail&atid=127&aid=28476&group_id=9
for sample blends and a discussion on the patch: how to use it and what influences the behavior of the character object.

Known problem: there is a crash if the "compound" option is set in the physics panel of the Character object.

1 files changed, 33 insertions, 8 deletions

diff --git a/source/blender/makesrna/intern/rna_object.c b/source/blender/makesrna/intern/rna_object.c
index 21c9187cbb8..7e3b368aa64 100644
--- a/source/blender/makesrna/intern/rna_object.c
+++ b/source/blender/makesrna/intern/rna_object.c
@@ -891,6 +891,9 @@ static int rna_GameObjectSettings_physics_type_get(PointerRNA *ptr)
 			ob->body_type = OB_BODY_TYPE_NO_COLLISION;
 		}
 	}
+	else if (ob->gameflag & OB_CHARACTER) {
+		ob->body_type = OB_BODY_TYPE_CHARACTER;
+	}
 	else if (ob->gameflag & OB_SENSOR) {
 		ob->body_type = OB_BODY_TYPE_SENSOR;
 	}
@@ -922,16 +925,16 @@ static void rna_GameObjectSettings_physics_type_set(PointerRNA *ptr, int value)
 	switch (ob->body_type) {
 		case OB_BODY_TYPE_SENSOR:
 			ob->gameflag |= OB_SENSOR | OB_COLLISION | OB_GHOST;
-			ob->gameflag &= ~(OB_OCCLUDER | OB_DYNAMIC | OB_RIGID_BODY | OB_SOFT_BODY | OB_ACTOR |
+			ob->gameflag &= ~(OB_OCCLUDER | OB_CHARACTER | OB_DYNAMIC | OB_RIGID_BODY | OB_SOFT_BODY | OB_ACTOR |
 			                  OB_ANISOTROPIC_FRICTION | OB_DO_FH | OB_ROT_FH | OB_COLLISION_RESPONSE | OB_NAVMESH);
 			break;
 		case OB_BODY_TYPE_OCCLUDER:
 			ob->gameflag |= OB_OCCLUDER;
-			ob->gameflag &= ~(OB_SENSOR | OB_RIGID_BODY | OB_SOFT_BODY | OB_COLLISION | OB_DYNAMIC | OB_NAVMESH);
+			ob->gameflag &= ~(OB_SENSOR | OB_RIGID_BODY | OB_SOFT_BODY | OB_COLLISION | OB_CHARACTER | OB_DYNAMIC | OB_NAVMESH);
 			break;
 		case OB_BODY_TYPE_NAVMESH:
 			ob->gameflag |= OB_NAVMESH;
-			ob->gameflag &= ~(OB_SENSOR | OB_RIGID_BODY | OB_SOFT_BODY | OB_COLLISION | OB_DYNAMIC | OB_OCCLUDER);
+			ob->gameflag &= ~(OB_SENSOR | OB_RIGID_BODY | OB_SOFT_BODY | OB_COLLISION | OB_CHARACTER | OB_DYNAMIC | OB_OCCLUDER);
 
 			if (ob->type == OB_MESH) {
 				/* could be moved into mesh UI but for now ensure mesh data layer */
@@ -940,24 +943,29 @@ static void rna_GameObjectSettings_physics_type_set(PointerRNA *ptr, int value)
 
 			break;
 		case OB_BODY_TYPE_NO_COLLISION:
-			ob->gameflag &= ~(OB_SENSOR | OB_RIGID_BODY | OB_SOFT_BODY | OB_COLLISION | OB_OCCLUDER | OB_DYNAMIC | OB_NAVMESH);
+			ob->gameflag &= ~(OB_SENSOR | OB_RIGID_BODY | OB_SOFT_BODY | OB_COLLISION | OB_CHARACTER | OB_OCCLUDER | OB_DYNAMIC | OB_NAVMESH);
 			break;
+		case OB_BODY_TYPE_CHARACTER:
+			ob->gameflag |= OB_COLLISION | OB_GHOST | OB_CHARACTER;
+			ob->gameflag &= ~(OB_SENSOR | OB_OCCLUDER | OB_DYNAMIC | OB_RIGID_BODY | OB_SOFT_BODY | OB_ACTOR
+		                     | OB_ANISOTROPIC_FRICTION | OB_DO_FH | OB_ROT_FH | OB_COLLISION_RESPONSE | OB_NAVMESH);
+		break;
 		case OB_BODY_TYPE_STATIC:
 			ob->gameflag |= OB_COLLISION;
-			ob->gameflag &= ~(OB_DYNAMIC | OB_RIGID_BODY | OB_SOFT_BODY | OB_OCCLUDER | OB_SENSOR | OB_NAVMESH);
+			ob->gameflag &= ~(OB_DYNAMIC | OB_RIGID_BODY | OB_SOFT_BODY | OB_OCCLUDER | OB_CHARACTER | OB_SENSOR | OB_NAVMESH);
 			break;
 		case OB_BODY_TYPE_DYNAMIC:
 			ob->gameflag |= OB_COLLISION | OB_DYNAMIC | OB_ACTOR;
-			ob->gameflag &= ~(OB_RIGID_BODY | OB_SOFT_BODY | OB_OCCLUDER | OB_SENSOR | OB_NAVMESH);
+			ob->gameflag &= ~(OB_RIGID_BODY | OB_SOFT_BODY | OB_OCCLUDER | OB_CHARACTER | OB_SENSOR | OB_NAVMESH);
 			break;
 		case OB_BODY_TYPE_RIGID:
 			ob->gameflag |= OB_COLLISION | OB_DYNAMIC | OB_RIGID_BODY | OB_ACTOR;
-			ob->gameflag &= ~(OB_SOFT_BODY | OB_OCCLUDER | OB_SENSOR | OB_NAVMESH);
+			ob->gameflag &= ~(OB_SOFT_BODY | OB_OCCLUDER | OB_CHARACTER | OB_SENSOR | OB_NAVMESH);
 			break;
 		default:
 		case OB_BODY_TYPE_SOFT:
 			ob->gameflag |= OB_COLLISION | OB_DYNAMIC | OB_SOFT_BODY | OB_ACTOR;
-			ob->gameflag &= ~(OB_RIGID_BODY | OB_OCCLUDER | OB_SENSOR | OB_NAVMESH);
+			ob->gameflag &= ~(OB_RIGID_BODY | OB_OCCLUDER | OB_CHARACTER | OB_SENSOR | OB_NAVMESH);
 
 			/* assume triangle mesh, if no bounds chosen for soft body */
 			if ((ob->gameflag & OB_BOUNDS) && (ob->boundtype < OB_BOUND_TRIANGLE_MESH)) {
@@ -1436,6 +1444,7 @@ static void rna_def_object_game_settings(BlenderRNA *brna)
 		                      "Collision Sensor, detects static and dynamic objects but not the other "
 		                      "collision sensor objects"},
 		{OB_BODY_TYPE_NAVMESH, "NAVMESH", 0, "Navigation Mesh", "Navigation mesh"},
+		{OB_BODY_TYPE_CHARACTER, "CHARACTER", 0, "Character", "Simple kinematic physics appropiate for game characters"},
 		{0, NULL, 0, NULL, NULL}
 	};
 
@@ -1529,6 +1538,22 @@ static void rna_def_object_game_settings(BlenderRNA *brna)
 	RNA_def_property_float_sdna(prop, NULL, "max_vel");
 	RNA_def_property_range(prop, 0.0, 1000.0);
 	RNA_def_property_ui_text(prop, "Velocity Max", "Clamp velocity to this maximum speed");
+	
+	prop= RNA_def_property(srna, "step_height", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "step_height");
+	RNA_def_property_range(prop, 0.0, 1.0);
+	RNA_def_property_ui_text(prop, "Step Height", "Maximum height of steps the character can run over");
+
+	prop= RNA_def_property(srna, "jump_speed", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "jump_speed");
+	RNA_def_property_range(prop, 0.0, 1000.0);
+	RNA_def_property_ui_text(prop, "Jump Force", "Upward velocity applied to the character when jumping (with the Motion actuator)");
+
+	prop= RNA_def_property(srna, "fall_speed", PROP_FLOAT, PROP_NONE);
+	RNA_def_property_float_sdna(prop, NULL, "fall_speed");
+	RNA_def_property_range(prop, 0.0, 1000.0);
+	RNA_def_property_ui_text(prop, "Fall Speed Max", "Maximum speed at which the character will fall");
+
 
 	/* lock position */
 	prop = RNA_def_property(srna, "lock_location_x", PROP_BOOLEAN, PROP_NONE);