Hi again, just have time now to follow up this one
So I modified my code a bit, by adding sh.setCullingMode(true) as suggested, and set the sun+projector position 400 unit above the ground, while (x,y) remains (0,0). Having this value, I think the shadow should be exactly below the teapot. But here is what I got on Xperia M:


Also, with the same code, I'm not sure why I got different shadow behaviour when I run my code on Nexus 9 tablet:


any idea why? 

I mean in this particular example, projector orientation is not set explicitly. Perhaps because it's already set by the lib?

This should help: http://www.jpct.net/forum2/index.php/topic,4333.msg32272.html#msg32272

So generally, how the projector should be treated to make the shadow works with vuforia marker/image target?

ah ok... Got it.
Cool, now it works. Thank you! 

Sorry, it was a mistake. Just ignore that line.
Yup, I'm sure that I use ShadowHelper from the jar 

Ok, here you go: http://jpct.de/download/example/ShadowExample.zip

And you'll need a slightly updated version of jPCT-AE for this to work correctly in portrait mode. You can grab this here: http://jpct.de/download/beta/jpct_ae.jar

It's based on Thomas.' work but simplified to one ShadowHelper class (a little similar to what desktop jPCT already offers). That's not saying that Thomas.' source code is too complicated, but it has a much larger scope than this small example, so i decided to cut some stuff and modify some parts. Anyway, without his great work, i couldn't have done this in just 2 hours.

Image:


I hope this helps somehow. This example uses a single shader for all receiver objects. It's based on the most complex default shader that jPCT-AE offers. So performance might not be optimal in all cases. In addition, it assumes that the depthmap is in texture unit 1, which might not be the case for multitextured objects. Anyway. it's just an example to get you started. I hope it helps.

If i find the time, i'll add it to the wiki in some modified form and if i find even more time, i'll add an even more modified version to the actual release...

Based on this example, I'm trying to have a transparent receiver by simply adding: plane.setTransparency(20)
And here is the result:


Is it possible to have a dark color shadow with a transparent receiver? Could you please give me a hint how to do that in jpct-ae?
Basically what I want to achieve is exactly the same with this post: http://www.jpct.net/forum2/index.php/topic,2626.msg19433.html. The only different thing is I'm using jpct-ae.

Yes, it has getClassType(). Here is the complete content of ObjectTracker.h :

/*===============================================================================
Copyright (c) 2014 Qualcomm Connected Experiences, Inc. All Rights Reserved.

Vuforia is a trademark of QUALCOMM Incorporated, registered in the United States
and other countries. Trademarks of QUALCOMM Incorporated are used with permission.

@file
    ObjectTracker.h

@brief
    Header file for ObjectTracker class.
===============================================================================*/
#ifndef _QCAR_OBJECT_TRACKER_H_
#define _QCAR_OBJECT_TRACKER_H_

// Include files
#include <QCAR/Tracker.h>

namespace QCAR
{

// Forward Declaration
class Trackable;
class DataSet;
class ImageTargetBuilder;
class TargetFinder;

/// ObjectTracker class.
/**
 *  The ObjectTracker tracks ObjectTargets, ImageTargets, CylinderTargets
 *  or MultiTargets contained in a DataSet.
 *  The ObjectTracker class provides methods for creating, activating and
 *  deactivating datasets. Note that methods for activating and deactivating
 *  datasets should not be called while the ObjectTracker is working at the
 *  same time. Doing so will make these methods block and wait until the
 *  tracker has finished.
 *  The suggested way of swapping datasets is during the execution of
 *  UpdateCallback, which guarantees that the ObjectTracker is not working
 *  concurrently. Alternatively the ObjectTracker can be stopped explicitly.
 *  However, this is a very expensive operation.
 */
class QCAR_API ObjectTracker : public Tracker
{
public:

    /// Returns the Tracker class' type
    static Type getClassType();

    /// Factory function for creating an empty dataset.
    /**
     *  Returns the new instance on success, NULL otherwise. Use
     *  DataSet::destroyDataSet() to destroy a DataSet that is no longer needed.
     */     
    virtual DataSet* createDataSet() = 0;

    /// Destroys the given dataset and releases allocated resources.
    /// Returns false if the given dataset is currently active.
    virtual bool destroyDataSet(DataSet* dataset) = 0;

    /// Activates the given dataset.
    /**
     *  This function will return true if the DataSet was successfully
     *  activated and false otherwise.
     *  The recommended way to activate datasets is during the execution of the
     *  UpdateCallback, which guarantees that the ObjectTracker is not working
     *  concurrently.
     */   
    virtual bool activateDataSet(DataSet* dataset) = 0;
   
    /// Deactivates the given dataset.
    /**
     *  This function will return true if the DataSet was successfully
     *  deactivated and false otherwise (E.g. because this dataset is not
     *  currently active).
     *  The recommended way to deactivate datasets is during the execution of
     *  the UpdateCallback, which guarantees that the ObjectTracker is not
     *  working concurrently.
     */   
    virtual bool deactivateDataSet(DataSet* dataset) = 0;

    /// Returns the idx-th active dataset. Returns NULL if no DataSet has
    /// been activated or if idx is out of range.
    virtual DataSet* getActiveDataSet(const int idx = 0) = 0;

    /// Returns the number of currently activated dataset.
    virtual int getActiveDataSetCount() const = 0;

    /// Returns instance of ImageTargetBuilder to be used for generated
    /// target image from current scene.
    virtual ImageTargetBuilder* getImageTargetBuilder() = 0;
   
    /// Returns instance of TargetFinder to be used for retrieving
    /// targets by cloud-based recognition.
    virtual TargetFinder* getTargetFinder() = 0;

    ///  Persist/Reset Extended Tracking
    /**
     *  In persistent Extended Tracking mode, the environment map will only
     *  ever be reset when the developer calls resetExtendedTracking().
     *  This function will return true if persistent Extended Tracking
     *  was set successfully (or was already set to the specified value)
     *  and false otherwise.
     */
    virtual bool persistExtendedTracking(bool on) = 0;
 
    /// Resets environment map for Extended Tracking
    /**
     *  Environment map can only be reset by the developer if persistent
     *  extended tracking is enabled.
     *  This function will return true if environment map was reset
     *  successfully and false otherwise.
     */
    virtual bool resetExtendedTracking() = 0;

};

} // namespace QCAR

#endif //_QCAR_OBJECT_TRACKER_H_


Hi all, I'm using https://github.com/sidneibjunior/vuforia-jpct as my base, and have successfully migrated to Vuforia 3.0.9 without major problem.
Now I'm trying to migrate to Vuforia 5.0.5, but I got this error while building my codes:

[armeabi-v7a] Compile++ arm  : ImageTargetsNative <= ImageTargets.cpp
[armeabi-v7a] SharedLibrary  : libImageTargetsNative.so
jni/ImageTargets.cpp:92: error: undefined reference to 'QCAR::ObjectTracker::getClassType()'
jni/ImageTargets.cpp:159: error: undefined reference to 'QCAR::ObjectTracker::getClassType()'
jni/ImageTargets.cpp:178: error: undefined reference to 'QCAR::ObjectTracker::getClassType()'
jni/ImageTargets.cpp:190: error: undefined reference to 'QCAR::ObjectTracker::getClassType()'
collect2: error: ld returned 1 exit status
make: *** [obj/local/armeabi-v7a/libImageTargetsNative.so] Error 1

---

Has anyone ever face the same problem? Or have successfully migrate to Vuforia 5? Please help... I really need to migrate.
I have tried to follow this instruction: https://developer.vuforia.com/library/articles/Solution/How-to-Migrate-an-Android-Project
But somehow still end up in "undefined reference" error... I don't know much about C++, but I need to use the native code for my project.

Thanks in advance.