Тут есть пример с кровью
http://redefy.net/2011/10/28/%d1%83%...api-chapter-3/
Надо подобное для away, что-то не нашел (наверняка есть), набросал простой танк который едет на плоскости

Код AS3:
package {
import away3d.cameras.*;import away3d.containers.*;import away3d.entities.*;
import away3d.lights.*;import away3d.materials.*;import away3d.materials.lightpickers.*;
import away3d.materials.methods.*;import away3d.primitives.*;import away3d.textures.*;
import flash.display.*;import flash.events.*;import flash.geom.*;import flash.ui.*;
/**
* попытка следов шин.
*/
public class CarAway3d extends Sprite {
private var container:ObjectContainer3D;
private var box:Mesh;
private var plane:Mesh;
private var view:View3D;
private var move:Boolean, revers:Boolean, right:Boolean, left:Boolean;
private var carPos:Point = new Point(), carRotation:Number = 0;
//private var controller:SimpleObjectController;
public function CarAway3d() {
stage.align = StageAlign.TOP_LEFT;
stage.scaleMode = StageScaleMode.NO_SCALE;
init();
}
private function init():void {
view = new View3D();
view.camera.lens.far = 10000;
view.camera.moveTo( -170, 1361, -1221);
view.camera.rotateTo(45, 2, 0);
addChild(view);
container = new ObjectContainer3D();
view.scene.addChild(container);
var sunLight:DirectionalLight = new DirectionalLight( -1, -0.4, 1);
with (sunLight) { color = 0xFFFF80; castsShadows = true; ambient = 1; diffuse = 1; specular = 1; }
container.addChild(sunLight);
var lightPicker:StaticLightPicker = new StaticLightPicker([sunLight]);
var filteredShadowMapMethod:SoftShadowMapMethod = new SoftShadowMapMethod(sunLight);
filteredShadowMapMethod.epsilon = 0.005;
var material:TextureMaterial = new TextureMaterial(new BitmapTexture(new BitmapData(2, 2, false, 0xFF0000)), true, true);
material.lightPicker = lightPicker;
material.shadowMethod = filteredShadowMapMethod;
material.ambient = 0.5;
container.addChild(box = new Mesh(new CubeGeometry(100, 50, 200, 1, 1, 1), material));
material = new TextureMaterial(new BitmapTexture(new BitmapData(2, 2, false, 0x00FF00)), true, true);
material.lightPicker = lightPicker;
material.shadowMethod = filteredShadowMapMethod;
material.ambient = 0.5;
container.addChild(plane = new Mesh(new PlaneGeometry(3000, 3000), material)).y = -20;
stage.addEventListener(KeyboardEvent.KEY_DOWN, keyHandler);
stage.addEventListener(KeyboardEvent.KEY_UP, keyHandler);
stage.addEventListener(Event.ENTER_FRAME, onEnterFrame);
}
private function onEnterFrame(e:Event):void {
var m:Matrix = new Matrix();
if (move) m.translate(0,10); if (revers) m.translate( 0,-10);
if (right) m.rotate(carRotation-=0.1); if (left) m.rotate( carRotation+=0.1);
if (!left && !right) m.rotate(carRotation);
carPos = carPos.add(m.transformPoint(new Point()));
box.rotationY = -carRotation * (180 / Math.PI);; //в градусах
box.x = carPos.x;
box.z = carPos.y;
view.render();
}
private function keyHandler(e:KeyboardEvent):void {
var k:int = e.keyCode; //w - 87 a - 65 d - 68 s - 83
if (e.type == KeyboardEvent.KEY_DOWN) var t:Boolean = true;
if (k == Keyboard.UP || k == 87) move = t;
if (k == Keyboard.DOWN || k == 83) revers = t;
if (k == Keyboard.RIGHT || k == 68) right = t;
if (k == Keyboard.LEFT || k == 65) left = t;
}
}
}
Надо как-то на большой плоскости отрисовать траекторию езды

Код AS3:
box.x = carPos.x;
box.z = carPos.y;
Ну или хоть что-то отрисовать, можно конечно плоскости добавлять вместо следов, но это не то что надо, будет некрасиво.