Milo221

03-24-2009, 08:56 AM

I am trying to write a simple application which overlays on a photograph 'markers' which highlight certain features. For example, say you where standing on a hill and took a photograph of the skyline - I would like to "mark" points of interest such as buildings etc.

Therefore, I am not writing a 3D graphics application - i'm just trying to get a 3D projection of the landscape in the photograph to be able to accurately annotate it.

To achieve this I know i'll need this information (which I have access to):

Camera: GPS Coordinates, Elevation, Compass Bearing and Tilt (up and down)

Points of interest: GPS Coordinates, Elevation

I am able to work out elements such as distance (in metres) and the angle from the coordinates the photograph was taken to the coordinates of the point of interest I wish to "mark", so in theory I have all the information I need to accurately annotate the photograph.

However...

I have no idea how I go about using 3D projection, creating a model of the world and converting it to screen pixels using OpenGL. I posted a similar message on another forum, whose members suggested using OpenGL to "plug in" the real world x,y,z coordinates and allow OpenGL to return the x,y screen pixels.

So before I spend another day hunting around for a tutorial on how to do this could someone kindly point me in the right direction? Any help and advice which will help me understand this would be greatly appreciated.

Oh and I will need to use the OpenGL ES 1.0 specification to create this if that makes any difference.

Many thanks

Therefore, I am not writing a 3D graphics application - i'm just trying to get a 3D projection of the landscape in the photograph to be able to accurately annotate it.

To achieve this I know i'll need this information (which I have access to):

Camera: GPS Coordinates, Elevation, Compass Bearing and Tilt (up and down)

Points of interest: GPS Coordinates, Elevation

I am able to work out elements such as distance (in metres) and the angle from the coordinates the photograph was taken to the coordinates of the point of interest I wish to "mark", so in theory I have all the information I need to accurately annotate the photograph.

However...

I have no idea how I go about using 3D projection, creating a model of the world and converting it to screen pixels using OpenGL. I posted a similar message on another forum, whose members suggested using OpenGL to "plug in" the real world x,y,z coordinates and allow OpenGL to return the x,y screen pixels.

So before I spend another day hunting around for a tutorial on how to do this could someone kindly point me in the right direction? Any help and advice which will help me understand this would be greatly appreciated.

Oh and I will need to use the OpenGL ES 1.0 specification to create this if that makes any difference.

Many thanks