test and fix for issue #651 (inverted rotation in Sky.vert)

jme3-core/src/main/resources/Common/MatDefs/Misc/Sky.j3md

@@ -12,7 +12,7 @@ MaterialDef Sky Plane {
         WorldParameters {
             ViewMatrix
             ProjectionMatrix
-            WorldMatrix
+            WorldMatrixInverse
         }
 
         Defines {

jme3-core/src/main/resources/Common/MatDefs/Misc/Sky.vert

@@ -1,7 +1,7 @@
 #import "Common/ShaderLib/GLSLCompat.glsllib"
 uniform mat4 g_ViewMatrix;
 uniform mat4 g_ProjectionMatrix;
-uniform mat4 g_WorldMatrix;
+uniform mat4 g_WorldMatrixInverse;
 
 uniform vec3 m_NormalScale;
 
@@ -22,5 +22,5 @@ void main(){
     gl_Position = g_ProjectionMatrix * pos;
 
     vec4 normal = vec4(inNormal * m_NormalScale, 0.0);
-    direction = (g_WorldMatrix * normal).xyz;
+    direction = (g_WorldMatrixInverse * normal).xyz;
 }

jme3-examples/src/main/java/jme3test/texture/TestSkyRotation.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright (c) 2017 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * Redistributions in binary form must reproduce the above copyright
+ *   notice, this list of conditions and the following disclaimer in the
+ *   documentation and/or other materials provided with the distribution.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
+ * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package jme3test.texture;
+
+import com.jme3.app.SimpleApplication;
+import com.jme3.input.KeyInput;
+import com.jme3.input.controls.ActionListener;
+import com.jme3.input.controls.KeyTrigger;
+import com.jme3.material.Material;
+import com.jme3.math.FastMath;
+import com.jme3.math.Quaternion;
+import com.jme3.math.Vector3f;
+import com.jme3.scene.Geometry;
+import com.jme3.scene.Mesh;
+import com.jme3.scene.Spatial;
+import com.jme3.scene.shape.Box;
+import com.jme3.util.SkyFactory;
+
+/**
+ * Simple application to test sky rotation with a cube-mapped sky.
+ *
+ * Press "T" to rotate the sky and floor to the camera's left. Press "Y" to
+ * rotate the sky and floor to the camera's right. Both should appear to move by
+ * the same amount in the same direction.
+ *
+ * See issue #651 for further information.
+ *
+ * @author Stephen Gold
+ */
+public class TestSkyRotation extends SimpleApplication implements ActionListener {
+
+    /**
+     * objects visible in the scene
+     */
+    private Spatial floor, sky;
+    /**
+     * Y-axis rotation angle in radians
+     */
+    private float angle = 0f;
+
+    public static void main(String[] arguments) {
+        TestSkyRotation application = new TestSkyRotation();
+        application.start();
+    }
+
+    @Override
+    public void simpleInitApp() {
+        /*
+         * Configure the camera.
+         */
+        flyCam.setEnabled(false);
+        Vector3f location = new Vector3f(-7f, 4f, 8f);
+        cam.setLocation(location);
+        Quaternion orientation;
+        orientation = new Quaternion(0.0037f, 0.944684f, -0.01067f, 0.327789f);
+        assert FastMath.approximateEquals(orientation.norm(), 1f);
+        cam.setRotation(orientation);
+        /*
+         * Attach a cube-mapped sky to the scene graph.
+         */
+        sky = SkyFactory.createSky(assetManager,
+                "Scenes/Beach/FullskiesSunset0068.dds",
+                SkyFactory.EnvMapType.CubeMap);
+        rootNode.attachChild(sky);
+        /*
+         * Attach a "floor" geometry to the scene graph.
+         */
+        Mesh floorMesh = new Box(10f, 0.1f, 10f);
+        floor = new Geometry("floor", floorMesh);
+        Material floorMaterial = new Material(assetManager,
+                "Common/MatDefs/Misc/Unshaded.j3md");
+        floorMaterial.setTexture("ColorMap",
+                assetManager.loadTexture("Interface/Logo/Monkey.jpg"));
+        floor.setMaterial(floorMaterial);
+        rootNode.attachChild(floor);
+        /*
+         * Configure mappings and listeners for keyboard input.
+         */
+        inputManager.addMapping("left", new KeyTrigger(KeyInput.KEY_T));
+        inputManager.addMapping("right", new KeyTrigger(KeyInput.KEY_Y));
+        inputManager.addListener(this, "left");
+        inputManager.addListener(this, "right");
+    }
+
+    /**
+     * Handle an input action from the user.
+     *
+     * @param name the name of the action
+     * @param ongoing true→depress key, false→release key
+     * @param ignored
+     */
+    @Override
+    public void onAction(String name, boolean ongoing, float ignored) {
+        if (!ongoing) {
+            return;
+        }
+        /*
+         * Update the Y-axis rotation angle based on which key was pressed.
+         */
+        if (name.equals("left")) {
+            angle += 0.1f; // radians
+            System.out.print("rotate floor and sky leftward ...");
+        } else if (name.equals("right")) {
+            angle -= 0.1f; // radians
+            System.out.printf("rotate floor and sky spatials rightward ...");
+        } else {
+            return;
+        }
+        /*
+         * Update the local rotations of both objects based on the angle.
+         */
+        System.out.printf(" to %.1f radians left of start%n", angle);
+        Quaternion rotation = new Quaternion();
+        rotation.fromAngleNormalAxis(angle, Vector3f.UNIT_Y);
+        floor.setLocalRotation(rotation);
+        sky.setLocalRotation(rotation);
+    }
+}