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By [GHRake]
In a 3d game the ViewMatrix is an array of 16 floats that defines your location in the world and your current viewport:
If you want to convert 3d coordinates into 2d coordinates in order to draw on your screen you have to find the ViewMatrix which can be difficult for beginners. I made a tutorial to show you the basic concept:
Upon finding the viewmatrix you must "transform" the coordinates by doing some matrix math outlined in this picture:
A World to Screen transformation function looks like this:
Code:
In a 3d game the ViewMatrix is an array of 16 floats that defines your location in the world and your current viewport:
If you want to convert 3d coordinates into 2d coordinates in order to draw on your screen you have to find the ViewMatrix which can be difficult for beginners. I made a tutorial to show you the basic concept:
Upon finding the viewmatrix you must "transform" the coordinates by doing some matrix math outlined in this picture:
A World to Screen transformation function looks like this:
Code:
Code:
WorldToScreen(float * mvpmatrix, Vec3D pos, Vec3D & playerScreenCoords)
{
//Matrix-vector Product, multiplying world(eye) coordinates by projection matrix=clipCoords
Vec4D clipCoords;
clipCoords.x=pos.x*mvpmatrix[0] + pos.y*mvpmatrix[4] + (pos.z)*mvpmatrix[8] + mvpmatrix[12];
clipCoords.y=pos.x*mvpmatrix[1] + pos.y*mvpmatrix[5] + (pos.z)*mvpmatrix[9] + mvpmatrix[13];
clipCoords.z=pos.x*mvpmatrix[2] + pos.y*mvpmatrix[6] + (pos.z)*mvpmatrix[10] + mvpmatrix[14];
clipCoords.w=pos.x*mvpmatrix[3] + pos.y*mvpmatrix[7] + (pos.z)*mvpmatrix[11] + mvpmatrix[15];
if (clipCoords.w < 0.1f)
return false;
//perspective division, dividing by clip.W=NDC
Vec3D normalizedDeviceCoordinates;
normalizedDeviceCoordinates.x=clipCoords.x / clipCoords.w;
normalizedDeviceCoordinates.y=clipCoords.y / clipCoords.w;
normalizedDeviceCoordinates.z=clipCoords.z / clipCoords.w;
//viewport tranform to screenCooords
playerScreenCoords.x=(windowWidth / 2 * normalizedDeviceCoordinates.x) + (normalizedDeviceCoordinates.x + windowWidth / 2);
playerScreenCoords.y=-(windowHeight / 2 * normalizedDeviceCoordinates.y) + (normalizedDeviceCoordinates.y + windowHeight / 2);
return true;
}