angle = (angle % (Math.PI*2));
this will make sure you travel round the object without changing direction

but remember that the cameras’ axis will still be aligned with its target

http://behlersartgalerie.de/tmp/carousel.html

sourcecode:

//———————————————————
import org.papervision3d.scenes.*;
import org.papervision3d.objects.*;
import org.papervision3d.cameras.*;
import org.papervision3d.materials.*;
import caurina.transitions.*;

var numOfItems:int = 10;
var radius:Number = 800;
var anglePer:Number = (Math.PI*2) / numOfItems;
var dsf:DropShadowFilter = new DropShadowFilter(10, 45, 0×000000, 0.3, 6, 6, 1, 3);

var con:Sprite = new Sprite();
con.x = stage.stageWidth * 0.5;
con.y = stage.stageHeight * 0.5;
addChild(con);
var scene:MovieScene3D = new MovieScene3D(con);
var cam:Camera3D = new Camera3D();
cam.zoom = 2;

for(var i:uint=1; i<=numOfItems; i++)
{
var bam:BitmapAssetMaterial = new BitmapAssetMaterial(”s” + i);
bam.oneSide = false;
bam.smooth = false;
var p:Plane = new Plane(bam, 162, 230, 2, 2);
p.y = Math.cos(i*anglePer) * radius;
p.z = Math.sin(i*anglePer) * radius;
p.rotationX = (-i*anglePer) * (180/Math.PI) + 270;
scene.addChild(p);
p.container.filters = [dsf];
}

var angleX:Number = anglePer;
var dest:Number = 1;

right.addEventListener(MouseEvent.CLICK, moveRight);
left.addEventListener(MouseEvent.CLICK, moveLeft);
this.addEventListener(Event.ENTER_FRAME, render);

function moveRight(e:Event):void
{
dest++;
Tweener.addTween(this, {angleX:dest*anglePer, time:0.5});
}

function moveLeft(e:Event):void
{
dest–;
Tweener.addTween(this, {angleX:dest*anglePer, time:0.5});
}

function render(e:Event):void
{
cam.y = Math.cos(angleX) * 1000;
cam.z = Math.sin(angleX) * 1000;
scene.renderCamera(cam);
}
//———————————————————————-

angle += (sp.mouseY) * 0.001;
cam.y = Math.cos(angle) * 1350;
cam.z = Math.sin(angle) * 1350;

and in calculatePlanes function plane positions:

tmpPlane.y = Math.cos(i * step) * radius;
tmpPlane.z = Math.sin(i * step ) * radius;
tmpPlane.rotationX = 90-stepDeg*i

It all right, but the movement around X is has PI/2 period and than carrousel turns back.
Help me please with this problem, I’m not so clever in trigonometry.