CityEngine to jmonkeyengine (Converting wavefront obj to j3o format)

Hi,

I am trying to import a wavefront obj of a city model created in city engine into jmonkeyengine sdk. I am completely newby to this jmonkeyengine.

I just clicked the import model icon in sdk, navigated to the folder where I had my .obj files and clicked open. But I get a null pointer exception like this

An Exception has occured when trying to load asset my_city_0
java.lang.NullPointerException
at com.jme3.gde.core.assets.ProjectAssetManager.getAssetFolderName(ProjectAssetManager.java:540)
at com.jme3.gde.core.assets.ProjectAssetManager.getRelativeAssetPath(ProjectAssetManager.java:384)
at com.jme3.gde.core.assets.AssetDataObject.getAssetKey(AssetDataObject.java:293)
at com.jme3.gde.core.assets.SpatialAssetDataObject.getAssetKey(SpatialAssetDataObject.java:67)
at com.jme3.gde.core.assets.SpatialAssetDataObject.loadAsset(SpatialAssetDataObject.java:94)
at com.jme3.gde.core.assets.SpatialAssetDataObject.loadAsset(SpatialAssetDataObject.java:53)
at com.jme3.gde.core.assets.AssetData.loadAsset(AssetData.java:130)
at com.jme3.gde.modelimporter.ModelImporterVisualPanel3.loadModel(ModelImporterVisualPanel3.java:92)
at com.jme3.gde.modelimporter.ModelImporterVisualPanel3.loadSettings(ModelImporterVisualPanel3.java:61)
at com.jme3.gde.modelimporter.ModelImporterWizardPanel3.readSettings(ModelImporterWizardPanel3.java:82)
at org.openide.WizardDescriptor.updateStateOpen(WizardDescriptor.java:867)
at org.openide.WizardDescriptor.updateState(WizardDescriptor.java:822)
at org.openide.WizardDescriptor._updateState(WizardDescriptor.java:800)
at org.openide.WizardDescriptor.goToNextStep(WizardDescriptor.java:1072)
at org.openide.WizardDescriptor.access$1900(WizardDescriptor.java:92)
at org.openide.WizardDescriptor$Listener$1.run(WizardDescriptor.java:2208)
at org.openide.WizardDescriptor.lazyValidate(WizardDescriptor.java:1516)
at org.openide.WizardDescriptor.access$2000(WizardDescriptor.java:92)
at org.openide.WizardDescriptor$Listener.actionPerformed(WizardDescriptor.java:2227)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.openide.util.WeakListenerImpl$ProxyListener.invoke(WeakListenerImpl.java:487)
at com.sun.proxy.$Proxy27.actionPerformed(Unknown Source)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6533)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6298)
at java.awt.Container.processEvent(Container.java:2237)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2295)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4889)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4526)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4467)
at java.awt.Container.dispatchEventImpl(Container.java:2281)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:109)
at java.awt.WaitDispatchSupport$2.run(WaitDispatchSupport.java:190)
at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:235)
at java.awt.WaitDispatchSupport$4.run(WaitDispatchSupport.java:233)
at java.security.AccessController.doPrivileged(Native Method)
at java.awt.WaitDispatchSupport.enter(WaitDispatchSupport.java:233)
at java.awt.Dialog.show(Dialog.java:1084)
at org.netbeans.core.windows.services.NbPresenter.superShow(NbPresenter.java:1086)
at org.netbeans.core.windows.services.NbPresenter.doShow(NbPresenter.java:1136)
at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:1108)
at org.netbeans.core.windows.services.NbPresenter.run(NbPresenter.java:131)
at org.netbeans.modules.openide.util.NbMutexEventProvider$Event.doEventAccess(NbMutexEventProvider.java:138)
at org.netbeans.modules.openide.util.NbMutexEventProvider$Event.readAccess(NbMutexEventProvider.java:98)
at org.netbeans.modules.openide.util.LazyMutexImplementation.readAccess(LazyMutexImplementation.java:94)
at org.openide.util.Mutex.readAccess(Mutex.java:218)
at org.netbeans.core.windows.services.NbPresenter.show(NbPresenter.java:1093)
at java.awt.Component.show(Component.java:1671)
at java.awt.Component.setVisible(Component.java:1623)
at java.awt.Window.setVisible(Window.java:1014)
at java.awt.Dialog.setVisible(Dialog.java:1005)
at com.jme3.gde.modelimporter.ImportModel.actionPerformed(ImportModel.java:93)
at org.openide.awt.AlwaysEnabledAction$1.run(AlwaysEnabledAction.java:199)
at org.openide.util.actions.ActionInvoker$1.run(ActionInvoker.java:95)
at org.openide.util.actions.ActionInvoker.doPerformAction(ActionInvoker.java:116)
at org.openide.util.actions.ActionInvoker.invokeAction(ActionInvoker.java:99)
at org.openide.awt.AlwaysEnabledAction.actionPerformed(AlwaysEnabledAction.java:202)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:2022)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.java:2348)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel.java:402)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:259)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonListener.java:252)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.AWTEventMulticaster.mouseReleased(AWTEventMulticaster.java:289)
at java.awt.Component.processMouseEvent(Component.java:6533)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3324)
at java.awt.Component.processEvent(Component.java:6298)
at java.awt.Container.processEvent(Container.java:2237)
at java.awt.Component.dispatchEventImpl(Component.java:4889)
at java.awt.Container.dispatchEventImpl(Container.java:2295)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4889)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:4526)
at java.awt.LightweightDispatcher.dispatchEvent(Container.java:4467)
at java.awt.Container.dispatchEventImpl(Container.java:2281)
at java.awt.Window.dispatchEventImpl(Window.java:2746)
at java.awt.Component.dispatchEvent(Component.java:4711)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:90)
at java.awt.EventQueue$4.run(EventQueue.java:731)
at java.awt.EventQueue$4.run(EventQueue.java:729)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
at org.netbeans.core.TimableEventQueue.dispatchEvent(TimableEventQueue.java:159)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

I want to know if anyone has successfully imported a model from cityengine to jmonkeyengine… Also is there a particular way to arrange my image,mtl and obj files for importing.

Thanks,
Charu Manivannan

I’m not sure jMonkeyEngine supports that format. But seems that CityEngine supports FBX and jMonkeyEngine has some kind of support on that format. You could try that instead.

Actually supported format is kinda poorly documented (or me having wooden eyes). Only the Blender way is described on in the documentation. It would be nice to see a list of the formats that can be imported and maybe even a list what is supported on the given format, somewhere on the main page. Is it currently Blender XML, FBX and glTF?

Still, maybe the glTF importer in jME is in best shape. So one option would be to convert the whatever CityEngine gives you to glTF and carry on from there…

obj

https://wiki.jmonkeyengine.org/jme3/intermediate/file_types.html#jmonkeyengine3-file-formats

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