Overlay disappears at specific distance

Hi,

I have used the ImageTarget Example combined with a Code Snippet to augment an Image with a 2D Overlay. (the Code snippet is attached at the end.) This works wonderful. But : when I move away with my Phone at a specific Distance then the overlay disappears. If I hold it parallel to the Image then it disappears completely if not then it starts to disappear with the part which is further away from the phone.

Then I used this method to measure the distance :

 QCAR::Matrix34F pose = result->getPose();        QCAR::Vec3F position(pose.data[3], pose.data[7], pose.data[11]);        float distance = sqrt(position.data[0] * position.data[0] +                              position.data[1] * position.data[1] +                              position.data[2] * position.data[2]);        LOG("distance: %f", distance);

the objects disapper with a distance of round about 2500.0 (float) 

Does anyone have a clue where i can increase this value ?

regards

Attachment

inserted into imagetargets cpp

QCAR::Vec2F tar                        getSize = ((QCAR::ImageTarget *) &trackable)->getSize();                        QCAR::Matrix44F modelViewProjection;                        SampleUtils::translatePoseMatrix(0.0f, 0.0f, kObjectScale,                                                         &modelViewMatrix.data[0]);                        SampleUtils::scalePoseMatrix(targetSize.data[0], targetSize.data[1], 1.0f,                                                     &modelViewMatrix.data[0]);                        SampleUtils::multiplyMatrix(&projectionMatrix.data[0],                                                    &modelViewMatrix.data[0] ,                                                    &modelViewProjection.data[0]);                         glUseProgram(shaderProgramID);                         glVertexAttribPointer(vertexHandle, 3, GL_FLOAT, GL_FALSE, 0,                                               (const GLvoid*) &planeVertices[0]);                         glVertexAttribPointer(normalHandle, 3, GL_FLOAT, GL_FALSE, 0,                                               (const GLvoid*) &planeNormals[0]);                         glVertexAttribPointer(textureCoordHandle, 2, GL_FLOAT, GL_FALSE, 0,                                               (const GLvoid*) &planeTexcoords[0]);                         glEnableVertexAttribArray(vertexHandle);                         glEnableVertexAttribArray(normalHandle);                         glEnableVertexAttribArray(textureCoordHandle);                         glActiveTexture(GL_TEXTURE0);                         glBindTexture(GL_TEXTURE_2D, thisTexture->mTextureID);                         glEnable(GL_BLEND);                                        glBlendFunc(GL_SRC_ALPHA,GL_ONE_MINUS_SRC_ALPHA);                         glUniformMatrix4fv(mvpMatrixHandle, 1, GL_FALSE,                                            (GLfloat*)&modelViewProjection.data[0] );                         glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_SHORT,                                        (const GLvoid*) &planeIndices[0]);

AND at the top of the FIle imagetargets.cpp

#include <QCAR/ImageTarget.h>static const float planeVertices[] ={    -0.5, -0.5, 0.0, 0.5, -0.5, 0.0, 0.5, 0.5, 0.0, -0.5, 0.5, 0.0,};static const float planeTexcoords[] ={    0.0, 0.0, 1.0, 0.0, 1.0, 1.0, 0.0, 1.0};static const float planeNormals[] ={    0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0, 0.0, 0.0, 1.0};static const unsigned short planeIndices[] ={    0, 1, 2, 0, 2, 3};