Add check for NB_PROBES identifier and set default value

jme3-core/src/main/resources/Common/ShaderLib/PBR.glsllib

@@ -2,6 +2,9 @@
 #ifndef PI
     #define PI 3.14159265358979323846264
 #endif
+#ifndef NB_PROBES
+    #define NB_PROBES 0
+#endif
 
 //Specular fresnel computation
 vec3 F_Shlick(float vh,	vec3 F0){

jme3-examples/src/main/java/jme3test/light/pbr/TestIssue1340.java

@@ -0,0 +1,92 @@
+package jme3test.light.pbr;
+
+import com.jme3.anim.SkinningControl;
+import com.jme3.app.SimpleApplication;
+import com.jme3.asset.plugins.UrlLocator;
+import com.jme3.environment.EnvironmentCamera;
+import com.jme3.environment.LightProbeFactory;
+import com.jme3.environment.generation.JobProgressAdapter;
+import com.jme3.light.DirectionalLight;
+import com.jme3.light.LightProbe;
+import com.jme3.math.ColorRGBA;
+import com.jme3.math.Vector3f;
+import com.jme3.scene.Node;
+import com.jme3.scene.Spatial;
+import com.jme3.system.AppSettings;
+
+/**
+ * This test case validates a shader compilation fix with a model using a PBR material in combination with a
+ * SkinningControl. When you run this application and you don't see a RenderException, the test is successful.
+ * For a detailed explanation consult the github issue: https://github.com/jMonkeyEngine/jmonkeyengine/issues/1340
+ * -rvandoosselaer
+ */
+public class TestIssue1340 extends SimpleApplication {
+
+    private Spatial model;
+    private int frame;
+
+    public static void main(String[] args) {
+        TestIssue1340 testIssue1340 = new TestIssue1340();
+        testIssue1340.setSettings(createSettings());
+        testIssue1340.start();
+    }
+
+    private static AppSettings createSettings() {
+        AppSettings settings = new AppSettings(true);
+        settings.setRenderer(AppSettings.LWJGL_OPENGL32);
+        return settings;
+    }
+
+    @Override
+    public void simpleInitApp() {
+        stateManager.attach(new EnvironmentCamera(32));
+
+        DirectionalLight light = new DirectionalLight(Vector3f.UNIT_Y.negate(), ColorRGBA.White);
+        rootNode.addLight(light);
+
+        assetManager.registerLocator("https://github.com/KhronosGroup/glTF-Sample-Models/raw/master/2.0/RiggedFigure/", UrlLocator.class);
+
+        model = assetManager.loadModel("/glTF-Embedded/RiggedFigure.gltf");
+        SkinningControl skinningControl = getSkinningControl(model);
+        if (skinningControl == null || !skinningControl.isHardwareSkinningPreferred()) {
+            throw new IllegalArgumentException("This test case requires a model with a SkinningControl and with Hardware skinning preferred!");
+        }
+
+        viewPort.setBackgroundColor(ColorRGBA.LightGray);
+    }
+
+    @Override
+    public void simpleUpdate(float tpf) {
+        frame++;
+        if (frame == 2) {
+            LightProbeFactory.makeProbe(stateManager.getState(EnvironmentCamera.class), rootNode, new JobProgressAdapter<LightProbe>() {
+                @Override
+                public void done(LightProbe result) {
+                    enqueue(() -> {
+                        rootNode.attachChild(model);
+                        rootNode.addLight(result);
+                    });
+                }
+            });
+        }
+    }
+
+    private SkinningControl getSkinningControl(Spatial model) {
+        SkinningControl control = model.getControl(SkinningControl.class);
+        if (control != null) {
+            return control;
+        }
+
+        if (model instanceof Node) {
+            for (Spatial child : ((Node) model).getChildren()) {
+                SkinningControl skinningControl = getSkinningControl(child);
+                if (skinningControl != null) {
+                    return skinningControl;
+                }
+            }
+        }
+
+        return null;
+    }
+
+}