The goal: (Due to movement and randomness, these screenshots are just a few possible ways the program can look. The colors should not change during a single run of the program)
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// most applications will want to extend the SimpleGame class import com.jme.app.SimpleGame; // a vector containing three float numbers; // used to store positions and translations import com.jme.math.Vector3f; import com.jme.math.Quaternion; import com.jme.math.Matrix3f; // geometric shapes used in program import com.jme.scene.shape.Box; import com.jme.scene.shape.Sphere; // use predefined colors and create custom colors import com.jme.renderer.ColorRGBA; // work with basic materials import com.jme.scene.state.MaterialState; // process user input import com.jme.input.InputHandler; import com.jme.input.KeyInput; import com.jme.input.KeyBindingManager; import com.jme.input.FirstPersonHandler; // display text import com.jme.scene.Text; import com.jmex.font2d.Text2D; import com.jmex.font2d.Font2D; // an internal vertex of the scenegraph tree; // use to group together objects, // apply render settings, which affects all child vertices import com.jme.scene.Node; import com.jme.scene.Spatial; import com.jme.scene.Geometry; // methods to change render settings import com.jme.renderer.Renderer; // camera and its controlling node import com.jme.renderer.Camera; import com.jme.scene.CameraNode; /** * Demonstrate two types of movement: * translation (uses Vectors) * and rotation (using Quaternions). */ public class MoveDemo extends SimpleGame { // a geometric shape that will be rendered Box myBox; // to control the camera movement, create a special node that controls the camera CameraNode cameraNode; public static void main(String[] args) { // create an instance of this program MoveDemo app = new MoveDemo(); // before the main program starts, display the graphics configuration window // where the user can choose among screen resolution, color depth, and full screen options app.setConfigShowMode(ConfigShowMode.AlwaysShow); // The start() method runs simpleInitGame(), // then starts the game loop: simpleUpdate(), then simpleRender() // To terminate game loop, call finish() app.start(); } protected void simpleInitGame() { // make the standard cursor visible. org.lwjgl.input.Mouse.setGrabbed(false); // SimpleGame class defaults mouse behavior to rotate view; here we disable this. ((FirstPersonHandler)input).getMouseLookHandler().setEnabled(false); // create a material to apply to geometric objects, use objects' default color, // apply to front and back, and assign rendering to root node MaterialState customMaterial = display.getRenderer().createMaterialState(); customMaterial.setColorMaterial(MaterialState.ColorMaterial.AmbientAndDiffuse); customMaterial.setMaterialFace(MaterialState.MaterialFace.FrontAndBack); rootNode.setRenderState(customMaterial); myBox = new Box("s", new Vector3f(0,0,0), 1, 1, 1 ); myBox.setRandomColors(); rootNode.attachChild( myBox ); buildInput(); // set up and attach the camera node cameraNode = new CameraNode("cameraNode", cam); rootNode.attachChild( cameraNode ); cameraNode.setLocalTranslation(0,0,-5); cameraNode.updateWorldData(0); } protected void simpleUpdate() { try { Thread.sleep(1000/120); } // force decrease in frames per second catch (Exception e) {} processInput(); } protected void simpleRender() { // nothing to add } // create input bindings public void buildInput() { // remove all pre-existing key assignments //KeyBindingManager.getKeyBindingManager().removeAll(); // exit the program KeyBindingManager.getKeyBindingManager().set( "exit", KeyInput.KEY_ESCAPE ); // display statistics (fps, number of tri's and quad's, etc.) KeyBindingManager.getKeyBindingManager().set( "toggle_stats", KeyInput.KEY_LSHIFT ); // WASDQZ typically moves the camera; // we are reassigning them to move the object. // Node local translation is relative to parent's coordinate system. KeyBindingManager.getKeyBindingManager().set( "nodeTranslateX+", KeyInput.KEY_Q ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateX-", KeyInput.KEY_W ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateY+", KeyInput.KEY_A ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateY-", KeyInput.KEY_S ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateZ+", KeyInput.KEY_Z ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateZ-", KeyInput.KEY_X ); // Node local rotation is in direction relative to the spatial's coordinate system. KeyBindingManager.getKeyBindingManager().set( "nodeRotateX+", KeyInput.KEY_1 ); KeyBindingManager.getKeyBindingManager().set( "nodeRotateY+", KeyInput.KEY_2 ); KeyBindingManager.getKeyBindingManager().set( "nodeRotateZ+", KeyInput.KEY_3 ); // camera translation KeyBindingManager.getKeyBindingManager().set( "cameraTranslateUp", KeyInput.KEY_I ); KeyBindingManager.getKeyBindingManager().set( "cameraTranslateDown", KeyInput.KEY_K ); KeyBindingManager.getKeyBindingManager().set( "cameraTranslateLeft", KeyInput.KEY_J ); KeyBindingManager.getKeyBindingManager().set( "cameraTranslateRight", KeyInput.KEY_L ); KeyBindingManager.getKeyBindingManager().set( "cameraTranslateForward", KeyInput.KEY_U ); KeyBindingManager.getKeyBindingManager().set( "cameraTranslateBackward", KeyInput.KEY_M ); // camera rotation KeyBindingManager.getKeyBindingManager().set( "cameraRotateUp", KeyInput.KEY_UP ); KeyBindingManager.getKeyBindingManager().set( "cameraRotateDown", KeyInput.KEY_DOWN ); KeyBindingManager.getKeyBindingManager().set( "cameraRotateLeft", KeyInput.KEY_LEFT ); KeyBindingManager.getKeyBindingManager().set( "cameraRotateRight", KeyInput.KEY_RIGHT ); // Node translation relative to camera KeyBindingManager.getKeyBindingManager().set( "nodeTranslateUp", KeyInput.KEY_T ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateDown", KeyInput.KEY_G ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateLeft", KeyInput.KEY_F ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateRight", KeyInput.KEY_H ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateForward", KeyInput.KEY_R ); KeyBindingManager.getKeyBindingManager().set( "nodeTranslateBackward", KeyInput.KEY_V ); // Node rotation relative to camera KeyBindingManager.getKeyBindingManager().set( "nodeRotateUp", KeyInput.KEY_4 ); KeyBindingManager.getKeyBindingManager().set( "nodeRotateDown", KeyInput.KEY_5 ); KeyBindingManager.getKeyBindingManager().set( "nodeRotateLeft", KeyInput.KEY_6 ); KeyBindingManager.getKeyBindingManager().set( "nodeRotateRight", KeyInput.KEY_7 ); } // process input entered since last update. public void processInput() { // defining speed in terms of tpf (time per frame) helps keep speed constant // across varying framerates float speed = 2*tpf; if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateX+", true)) myBox.getLocalTranslation().addLocal(speed,0,0); // alternatively, we could write // myBox.getLocalTranslation().addLocal( Vector3f.UNIT_X.mult(speed) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateX-", true)) myBox.getLocalTranslation().addLocal(-speed,0,0); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateY+", true)) myBox.getLocalTranslation().addLocal(0,speed,0); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateY-", true)) myBox.getLocalTranslation().addLocal(0,-speed,0); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateZ+", true)) myBox.getLocalTranslation().addLocal(0,0,speed); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateZ-", true)) myBox.getLocalTranslation().addLocal(0,0,-speed); // Note: movement ROTATION is in direction relative to the spatial's coordinate system. if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeRotateX+", true)) myBox.getLocalRotation().multLocal( new Quaternion().fromAngleAxis(speed, Vector3f.UNIT_X) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeRotateY+", true)) myBox.getLocalRotation().multLocal( new Quaternion().fromAngleAxis(speed, Vector3f.UNIT_Y) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeRotateZ+", true)) myBox.getLocalRotation().multLocal( new Quaternion().fromAngleAxis(speed, Vector3f.UNIT_Z) ); // camera translation if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraTranslateLeft")) cameraNode.getLocalTranslation().addLocal( cam.getLeft().mult( speed ) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraTranslateRight")) cameraNode.getLocalTranslation().addLocal( cam.getLeft().mult( -speed ) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraTranslateUp")) cameraNode.getLocalTranslation().addLocal( cam.getUp().mult( speed ) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraTranslateDown")) cameraNode.getLocalTranslation().addLocal( cam.getUp().mult( -speed ) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraTranslateForward")) cameraNode.getLocalTranslation().addLocal( cam.getDirection().mult( speed ) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraTranslateBackward")) cameraNode.getLocalTranslation().addLocal( cam.getDirection().mult( -1 * speed ) ); // camera rotation -- mathematics calculated in a separate method if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraRotateUp")) cameraRotate( cameraNode, -speed / 3, cam.getLeft().clone() ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraRotateDown")) cameraRotate( cameraNode, speed / 3, cam.getLeft().clone() ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraRotateLeft")) cameraRotate( cameraNode, speed / 3, cam.getUp().clone() ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("cameraRotateRight")) cameraRotate( cameraNode, -speed / 3, cam.getUp().clone() ); // node translation relative to camera. // NOTE: this code only works when node is attached directly to root, // otherwise, a coordinate transformation is required. if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateUp")) myBox.getLocalTranslation().addLocal( cam.getUp().clone().mult(speed) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateDown")) myBox.getLocalTranslation().addLocal( cam.getUp().clone().mult(-speed) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateLeft")) myBox.getLocalTranslation().addLocal( cam.getLeft().clone().mult(speed) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateRight")) myBox.getLocalTranslation().addLocal( cam.getLeft().clone().mult(-speed) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateForward")) myBox.getLocalTranslation().addLocal( cam.getDirection().clone().mult(speed) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeTranslateBackward")) myBox.getLocalTranslation().addLocal( cam.getDirection().clone().mult(-speed) ); // node rotation relative to camera // NOTE: since rotation is relative to a spatials's orientation, // we must convert a "global vector" (the vector around which we will rotate) // into a "local vector" (coordinates converted according to spatial's orientation) if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeRotateUp")) myBox.getLocalRotation().multLocal( new Quaternion().fromAngleAxis( speed, convertGlobalToLocal(cam.getLeft().clone(), myBox )) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeRotateDown")) myBox.getLocalRotation().multLocal( new Quaternion().fromAngleAxis( -speed, convertGlobalToLocal(cam.getLeft().clone(), myBox )) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeRotateLeft")) myBox.getLocalRotation().multLocal( new Quaternion().fromAngleAxis( -speed, convertGlobalToLocal(cam.getUp().clone(), myBox )) ); if (KeyBindingManager.getKeyBindingManager().isValidCommand("nodeRotateRight")) myBox.getLocalRotation().multLocal( new Quaternion().fromAngleAxis( speed, convertGlobalToLocal(cam.getUp().clone(), myBox )) ); } public void cameraRotate(CameraNode camNode, float rotateAngle, Vector3f rotateAxis) { Quaternion Q = new Quaternion(); Matrix3f M = new Matrix3f(); Q.fromAngleAxis( rotateAngle, rotateAxis ); M = Q.toRotationMatrix(); Camera tempCamera = camNode.getCamera(); M.multLocal( tempCamera.getDirection() ); M.multLocal( tempCamera.getUp() ); M.multLocal( tempCamera.getLeft() ); tempCamera.normalize(); camNode.updateFromCamera(); } public Vector3f convertGlobalToLocal(Vector3f v, Spatial n) { // determine the global rotation of the node under consideration Quaternion Q = n.getWorldRotation().clone(); // convert to a matrix Matrix3f M = Q.toRotationMatrix(); // the next two lines contain the important math M = M.invert(); Vector3f V = M.mult( v ); return V; } }