JavaScript / HTML5 3D Modeling Help Needed | Objects rotate

[JohnRock076]

Hi All.

I have a slight problem.

I am building a 3D Modeling framework in JavaScript that draws objects on a canvass (HTML5).

However, after object creation, I rotate it by 1 degree around any axis and then it seems to do a 90 degree rotation all by itself.

I have sat hours on end and can't seem to find what causes this. Maybe some fresh eyes will help?

Here the code that seems to give me all this uphill:

NB:This is just some of the code. See attached for all files needed!

function RotateObjectAboutY(ObjectToRotate, YRotationInDegrees)
{
    YRotationInDegrees = (-1)*YRotationInDegrees;
    pi = 3.14159;
    YRotRads = (YRotationInDegrees/360)*(2*pi);
    var CenterX = ObjectCenterX[ObjectToRotate];
    var CenterY = ObjectCenterY[ObjectToRotate];
    var CenterZ = ObjectCenterZ[ObjectToRotate];
    var ObjectsFirstNode = ObjectFirstNode[ObjectToRotate];
    var ObjectsLastNode  = ObjectLastNode[ObjectToRotate];
	var deltaY=0;
	var deltaX=0;
	var R=0;
	var OldAngleRads=0;
	var NewAngleRads=0;
    for(var i = ObjectsFirstNode;i<= ObjectsLastNode;i++)
	{
        deltaX = (NodeWX[i] - CenterX);
        deltaZ = (NodeWZ[i] - CenterZ);
        R   = Math.sqrt(Math.pow(deltaX,2) + Math.pow(deltaZ,2));
        OldAngleRads = Math.atan2(deltaX, deltaZ);
        NewAngleRads = OldAngleRads + YRotRads;
        NodeWX[i] = CenterX + R*Math.cos(NewAngleRads);
        NodeWZ[i] = CenterZ + R*Math.sin(NewAngleRads);
    }
}
function DrawObject(id)
{
	var Cam2NodeX = 0;
	var Cam2NodeY = 0;
	var Cam2NodeZ = 0;
	var ipX = 0;
	var ipY = 0;
	var ipZ = 0;
	var numerator = 0;
	var denominator = 0;
	var t = 0;
	var Ctr2ipX = 0;
	var Ctr2ipY = 0;
	var Ctr2ipZ = 0;
	var PX = 0;
	var SCM = 0;
	var PY = 0;
	var xx1=0;
	var yy1=0;
	var xx2=0;
	var yy2=0;
    var ObjectToDraw = id;
    var FirstNodeOfObject = ObjectFirstNode[ObjectToDraw];
    var LastNodeOfObject  = ObjectLastNode[ObjectToDraw];
    var FirstLineOfObject = ObjectFirstLine[ObjectToDraw];
    var LastLineOfObject  = ObjectLastLine[ObjectToDraw];
    Cam2CtrX = (VCtrX - CamX);
    Cam2CtrY = (VCtrY - CamY);
    Cam2CtrZ = (VCtrZ - CamZ);
    var LenCam2Ctr = Math.sqrt(Math.pow(Cam2CtrX,2) + Math.pow(Cam2CtrY,2) + Math.pow(Cam2CtrZ,2));
    var virtualXi = (-1)*(Cam2CtrZ);
    var virtualXj = 0;
    var virtualXk = Cam2CtrX;
    var LenVirtualX = Math.sqrt(Math.pow(virtualXi,2) + Math.pow(virtualXj,2) + Math.pow(virtualXk,2));
    virtualXi = virtualXi / LenVirtualX;
    virtualXj = virtualXj / LenVirtualX;
    virtualXk = virtualXk / LenVirtualX;
    var virtualYi = (-1)*(virtualXk * Cam2CtrY);
    var virtualYj = (virtualXk * Cam2CtrX) - (virtualXi * Cam2CtrZ);
    var virtualYk = (virtualXi * Cam2CtrY);
    var LenVirtualY = Math.sqrt(Math.pow(virtualYi,2) + Math.pow(virtualYj,2) + Math.pow(virtualYk,2));
    virtualYi = virtualYi / LenVirtualY;
    virtualYj = virtualYj / LenVirtualY;
    virtualYk = virtualYk / LenVirtualY;
    virtualXi = virtualXi / LenCam2Ctr;
    virtualXj = virtualXj / LenCam2Ctr;
    virtualXk = virtualXk / LenCam2Ctr;
    virtualYi = virtualYi / LenCam2Ctr;
    virtualYj = virtualYj / LenCam2Ctr;
    virtualYk = virtualYk / LenCam2Ctr;
	var canvas = document.getElementById("myCanvas");
    var context = canvas.getContext("2d");
    for(var i = FirstNodeOfObject;i<=LastNodeOfObject;i++)
	{
        Cam2NodeX = (NodeWX[i] - CamX);
        Cam2NodeY = (NodeWY[i] - CamY);
        Cam2NodeZ = (NodeWZ[i] - CamZ);
        numerator   = Math.pow(Cam2CtrX,2) + Math.pow(Cam2CtrY,2) + Math.pow(Cam2CtrZ,2);
        denominator = (Cam2NodeX * Cam2CtrX) + (Cam2NodeY * Cam2CtrY) + (Cam2NodeZ * Cam2CtrZ);
        t = (numerator / denominator);
        ipX = CamX + Cam2NodeX*t;
        ipY = CamY + Cam2NodeY*t;
        ipZ = CamZ + Cam2NodeZ*t;
        Ctr2ipX = (ipX - VCtrX);
        Ctr2ipY = (ipY - VCtrY);
        Ctr2ipZ = (ipZ - VCtrZ);
        PX = (Ctr2ipX*virtualXi) + (Ctr2ipY*virtualXj) + (Ctr2ipZ*virtualXk);
        SCM = 500   //Secondary Scale Multiplier.
        NodeSX[i] = ScrCenterX + (SCM*ZoomFac * PX);
        PY = (Ctr2ipX*virtualYi) + (Ctr2ipY*virtualYj) + (Ctr2ipZ*virtualYk);
        NodeSY[i] = ScrCenterY - (SCM*ZoomFac * PY);
    }
	for(var i1 = FirstLineOfObject;i1<=LastLineOfObject;i1++)
	{
		xx1 = NodeSX[LineInode[i1]];
		yy1 = NodeSY[LineInode[i1]];
		xx2 = NodeSX[LineJnode[i1]];
		yy2 = NodeSY[LineJnode[i1]];
		context.beginPath();
		context.moveTo(Math.round(xx1),Math.round(yy1));
		context.lineTo(Math.round(xx2),Math.round(yy2));
		context.strokeStyle = ObjectColor[ObjectToDraw];
		context.lineWidth = 1;
		context.lineCap = "butt";
		context.stroke();
	}
}
function CreateCone(ConeName, radius, numSides, coneheight, ConeColor)
{
    var NC = NodeCount;
    var pi = 3.14159;
    var wedgeAngle = (2*pi)/numSides;
    for(var i=1;i<=numSides;i++)
	{
        NodeWX[NC + i] = radius*Math.cos((i-1)*wedgeAngle);
        NodeWY[NC + i] = 0;
        NodeWZ[NC + i] = radius*Math.sin((i-1)*wedgeAngle);
    }
    NodeWX[NC + numSides + 1] = 0;
    NodeWY[NC + numSides + 1] = coneheight;
    NodeWZ[NC + numSides + 1] = 0;
    var LC = LineCount;
    for (var i=1;i<=(numSides-1);i++)
	{
        LineInode[LC + i] = (NC + i);
        LineJnode[LC + i] = (NC + i + 1);
    }
    LineInode[LC + numSides] = (NC + numSides);
    LineJnode[LC + numSides] = (NC + 1);
    for(var i=1;i<=numSides;i++)
	{
        LineInode[LC + numSides + i] = (NC + i);
        LineJnode[LC + numSides + i] = (NC + numSides + 1);
    }
    var OC = ObjectCount;
    ObjectName[OC + 1]         = ConeName;
    ObjectColor[OC + 1]        = ConeColor;
    ObjectFirstNode[OC + 1]     = (NC + 1);
    ObjectLastNode[OC + 1]      = (NC + numSides + 1);
    ObjectFirstLine[OC + 1]     = (LC + 1);
    ObjectLastLine[OC + 1]      = (LC + 2*numSides);
    ObjectVisible[OC + 1]       = 1;
    ObjectLineThickness[OC + 1] = 1;
    ObjectType[OC + 1]         = CurrentGroupName;
    ObjectDeviceType[OC + 1]   = CurrentDeviceName;
    ObjectCenterX[OC + 1]       = 0;
    ObjectCenterY[OC + 1]       = coneheight/2;
    ObjectCenterZ[OC + 1]       = 0;
    NodeCount   = NodeCount + numSides + 1;
    LineCount  = LineCount + 2*numSides;
    ObjectCount = ObjectCount + 1;
}

ANY help in this would be super.

Many thanks in advance!

[JohnRock076]

Any one looked at this yet??