mat4.lookAt()
below is giving me unexpected results.
Please see the images associated with the 3 test examples. The first example is "correct", and the others seem clipped, but I cannot figure why. The perspectives and distances from the camera seem correct on all, but except for the first, I am not getting the whole view I want. Can you suggest what I need to do adjust this?
function draw() {
gl.clearColor(bgcolor[0],bgcolor[1],bgcolor[2],1);
gl.clear(gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT);
if (document.getElementById("persproj").checked) {
mat4.perspective(projection, Math.PI/4, 1, 4, 8);
}
else {
mat4.ortho(projection,-2.5, 2.5, -2.5, 2.5, 4, 8);
}
gl.uniformMatrix4fv(uProjection, false, projection );
mat4.lookAt(modelview, [0,0,6], [0,0,0], [0,1,0]); // This is the key line
mat4.rotateX(modelview, modelview, rotateX);
mat4.rotateY(modelview, modelview, rotateY);
gl.uniformMatrix4fv(uModelview, false, modelview );
mat3.normalFromMat4(normalMatrix, modelview);
gl.uniformMatrix3fv(uNormalMatrix, false, normalMatrix);
gl.uniform1i( uLit, 0 ); // The lines representing the coordinate axes are not lit.
gl.lineWidth(4);
drawPrimitive( gl.LINES, [1,0,0,1], [ -2,0,0, 2,0,0] );
drawPrimitive( gl.LINES, [0,1,0,1], [ 0,-2,0, 0,2,0] );
drawPrimitive( gl.LINES, [0,0,1,1], [ 0,0,-2, 0,0,2] );
gl.lineWidth(1);
if (leftColors.length>0){
drawTurtles(linecolors,moves,leftColors,rightColors,backColors,bottoms,lefts,rights,backs,bottomNs,leftNs,rightNs,backNs);
}
}
mat4.lookAt(modelview, [0,0,6], [0,0,0], [0,1,0])
mat4.lookAt(modelview, [0,0,8], [0,0,0], [0,1,0])
mat4.lookAt(modelview, [0,0,4], [0,0,0], [0,1,0])