Projection

[beakie]

Can anyone offer a suggestion as to what is happening here?

http://imgur.com/bHq67

I have been using this coordinate projection code for a while using basic lines
to draw...and it always seemed to work. It wasn't until I started to implement
the painters algorithm that i realised something must be wrong with the
projection code.

The following values were used. I have drawn lines from different vertices to
each point in a different colour in the picture in an attempt to show where
these points lie in my 3d image.

//Red lines
CameraPosition = coordinate(0, 20, 100);

//Green lines
ViewerPosition = coordinate(0, 10, 100);

//Blue lines = coordinate(0, 0, 0) 

This is the function I use.

plot RotateScaleTranslate3D::plot3DCoordinate(ProjectionSettings * ps, coordinate c) {
	plot coorTemp;
	vector<float> d;
	coordinate a = coordinate(c.X * ps->Scaler.X * ps->Zoom.X,
								c.Y * ps->Scaler.Y * ps->Zoom.Y,
								c.Z * ps->Scaler.Z * ps->Zoom.Z);
	coordinate cp = ps->CameraPosition;
	eulerAngles cr = ps->CameraRotation;
	coordinate vp = ps->ViewerPosition;
	float temp = myMaths::cosine(cr.Y) * (a.Z - cp.Z) + myMaths::sine(cr.Y) * (myMaths::sine(cr.Z) * (a.Y - cp.Y) + myMaths::cosine(cr.Z) * (a.X - cp.X));
	d.X = myMaths::cosine(cr.Y) * (myMaths::sine(cr.Z) * (a.Y - cp.Y) + myMaths::cosine(cr.Z) * (a.X - cp.X)) - myMaths::sine(cr.Y) * (a.Z - cp.Z);
	d.Y = myMaths::sine(cr.X) * temp + myMaths::cosine(cr.X) * (myMaths::cosine(cr.Z) * (a.Y - cp.Y) - myMaths::sine(cr.Z) * (a.X - cp.X));
	d.Z = myMaths::cosine(cr.X) * temp - myMaths::sine(cr.X) * (myMaths::cosine(cr.Z) * (a.Y - cp.Y) - myMaths::sine(cr.Z) * (a.X - cp.X));
	if (ps->CoordinateInvertX) { d.X = 0 - d.X; };
	if (ps->CoordinateInvertY) { d.Y = 0 - d.Y; };
	if (ps->CoordinateInvertZ) { d.Z = 0 - d.Z; };
	coorTemp.x = (plotElement) ((d.X - vp.X) * (vp.Z / d.Z));
	coorTemp.y = (plotElement) ((d.Y - vp.Y) * (vp.Z / d.Z));
	coorTemp.x += ps->Offset.x + ps->ManualOffset.x; //manual is shit. get rid.
	coorTemp.y += ps->Offset.y + ps->ManualOffset.y;
	return coorTemp;
};

I don't understand why the viewerposition is within the scene and not where I am
viewing. i would expect the green lines to come toward me.

The cube is not rendered properly because the z buffer values are calculated
from the viewerposition coordinate which is in the middle of the image.

Any ideas, please?

[beakie]

In case anyone wants to see the value of the cubes coordinates...

		model3D * objBase = new model3D();
		objBase->triangleList.addItem(mappedTriangle(0, 1, 3, cRed));
		objBase->triangleList.addItem(mappedTriangle(1, 2, 3, cRed));
		objBase->triangleList.addItem(mappedTriangle(4, 5, 6, cGreen));
		objBase->triangleList.addItem(mappedTriangle(4, 6, 7, cGreen));
		objBase->triangleList.addItem(mappedTriangle(2, 3, 7, cBlue));
		objBase->triangleList.addItem(mappedTriangle(2, 6, 7, cBlue));
		objBase->triangleList.addItem(mappedTriangle(0, 4, 5, cPurple));
		objBase->triangleList.addItem(mappedTriangle(0, 1, 5, cPurple));
		objBase->triangleList.addItem(mappedTriangle(3, 4, 7, cOrange));
		objBase->triangleList.addItem(mappedTriangle(0, 3, 4, cOrange));
		objBase->triangleList.addItem(mappedTriangle(1, 2, 5, cYellow));
		objBase->triangleList.addItem(mappedTriangle(2, 5, 6, cYellow));
		objBase->pointList.addItem(coordinate(-50, -60, -50));
		objBase->pointList.addItem(coordinate(-50, -20, -50));
		objBase->pointList.addItem(coordinate(50, -20, -50));
		objBase->pointList.addItem(coordinate(50, -60, -50));
		objBase->pointList.addItem(coordinate(-50, -60, 50));
		objBase->pointList.addItem(coordinate(-50, -20, 50));
		objBase->pointList.addItem(coordinate(50, -20, 50));
		objBase->pointList.addItem(coordinate(50, -60, 50));
		dModel->modelList.addItem(objBase);