Log in or register to post comments

what is the meaning of camera position?

April 1, 2013 - 11:03am #1

hey there.. can i ask a question here? i just want to know more about camera position.. i tried to integrate JPCT-ae to vuforia, but i got stuck when i want to "Setting the FOV". expecialy in these codes

QCAR::Matrix44F inverseMV = SampleMath::Matrix44FInverse(modelViewMatrix);
	QCAR::Matrix44F invTranspMV = SampleMath::Matrix44FTranspose(inverseMV);

	//Camera position
	float cam_x = invTranspMV.data[12];
	float cam_y = invTranspMV.data[13];
	float cam_z = invTranspMV.data[14];

	//Camera orientation axis (camera viewing direction, camera right direction and camera up direction)
	float cam_right_x = invTranspMV.data[0];
	float cam_right_y = invTranspMV.data[1];
	float cam_right_z = invTranspMV.data[2];

	float cam_up_x = -invTranspMV.data[4];
	float cam_up_y = -invTranspMV.data[5];
	float cam_up_z = -invTranspMV.data[6];

	float cam_dir_x = invTranspMV.data[8];
	float cam_dir_y = invTranspMV.data[9];
	float cam_dir_z = invTranspMV.data[10];

i explore the threads that explain this here, and i got this thread, https://developer.vuforia.com/forum/faq/technical-how-do-i-get-camera-position. i'm sorry my question maybe too silly but i really really blind what is these codes means generally? I don't know what does Camera Position means?

what is the meaning of camera position?

April 2, 2013 - 8:44am #4

You're welcome.

what is the meaning of camera position?

April 2, 2013 - 8:40am #3

Thank you so much for the references... i will read it of course. hope i will understand more about the concept..

what is the meaning of camera position?

April 2, 2013 - 4:25am #2

Hi,

the camera position represents how to camera is positioned with respect to the world reference frame; in Vuforia applications (see ImageTargets sample for instance), the relationship between the world and the camera is defined vua the Pose matrix;

To get you started on these topics about 3D maths and world vs camea concepts (which are the basics in AR applications), you may want to read this articles:

https://developer.vuforia.com/resources/dev-guide/pose-matrix-explained

https://developer.vuforia.com/resources/dev-guide/positioning-3d-content

http://www.opengl.org/archives/resources/faq/technical/transformations.htm

 

Log in or register to post comments