Frederic Gillet wrote:
>
> >
> > > My problem is to have lighting enabled AND to see the colors defined in the
> > > geometry array at the same time ...
As Tim and I have said, Java 3D can (and does) do what you want.
I have attached the source for a program that demonstrates the
per-vertex colors being used for shading.
It is a simple example, one plane with a different color for each
vertex. The plane is lit by a single directional light (0, -1, 0).
As the plane rotates, the colors change due to the angles between
the normals and the light direction. When the plane faces the
viewer, it appears all white for the specular reflection dominates
the shading. At other angles, the color varies across the face
because each vertex is a different color and the normals are
moving with the rotation of the plane. I did not enable back
face viewing, but if it were, the back would be dark gray-ish
due to the ambient lighting.
Lighting is a complex problem. In many cases, lighting depends
on the normal vectors and the direction of the light.
Many people have trouble getting normals specified correctly. Be
sure to normalize normals - I am not sure what effect non-
normalized normals will have.
Sometimes the direction of the light is a problem. As Tim has
suggested, you should look at the direction of your light.
Also, the specification of bounds is a common problem. If the
bounds of the light does not intersect the bounds for an object
then it will not illuminate the object.
I hope this helps.
Dennis
--
-----
Dennis J Bouvier
[EMAIL PROTECTED]
Find the Java 3D Tutorial "Getting Started with the Java 3D API" at
http://sun.com/desktop/java3d/collateral
/*
* LitPlane2App.java 1.0 99/04/12
*
* Copyright (c) 1999 Sun Microsystems, Inc. All Rights Reserved.
*
* Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
* modify and redistribute this software in source and binary code form,
* provided that i) this copyright notice and license appear on all copies of
* the software; and ii) Licensee does not utilize the software in a manner
* which is disparaging to Sun.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
* IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
* NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
* LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
* OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
* LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
* INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
* CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
* OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGES.
*
* This software is not designed or intended for use in on-line control of
* aircraft, air traffic, aircraft navigation or aircraft communications; or in
* the design, construction, operation or maintenance of any nuclear
* facility. Licensee represents and warrants that it will not use or
* redistribute the Software for such purposes.
*/
/*
* This program demonstrates the absence of automatic shadowing
* in Java 3D. The scene has a sphere above a plane lit from
* above. Theer is no shadow of the sphere on the plane.
*
* Note that no real time 3D graphics API provides automatic
* shadowing.
*
* This application (or a version of it) generated one or more
* of the images in Chapter 6 of Getting Started with the Java 3D API.
* The Java 3D Turtorial.
*
* See http://www.sun.com/desktop/java3d/collateral for more information.
*
*/
import java.applet.Applet;
import java.awt.BorderLayout;
import java.awt.Label;
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.universe.*;
import com.sun.j3d.utils.geometry.*;
import javax.media.j3d.*;
import javax.vecmath.*;
public class LitPlane2App extends Applet {
public class LitPlane extends Shape3D {
LitPlane() {
this.setGeometry(createGeometry());
this.setAppearance(createAppearance());
}
Geometry createGeometry(){
QuadArray plane = new QuadArray(4, GeometryArray.COORDINATES
| GeometryArray.NORMALS
| GeometryArray.COLOR_3
);
Point3f p = new Point3f(-1.0f, 0.5f, -1.0f);
plane.setCoordinate(0, p);
p.set(-1.0f, -0.5f, 1.0f);
plane.setCoordinate(1, p);
p.set( 1.0f, -0.5f, 1.0f);
plane.setCoordinate(2, p);
p.set( 1.0f, 0.5f, -1.0f);
plane.setCoordinate(3, p);
Vector3f n = new Vector3f(0.0f, 0.7f, 0.7f);
plane.setNormal(0, n);
plane.setNormal(1, n);
plane.setNormal(2, n);
plane.setNormal(3, n);
plane.setColor(0, new Color3f(1.0f, 0.0f, 0.0f));
plane.setColor(1, new Color3f(0.0f, 1.0f, 0.0f));
plane.setColor(2, new Color3f(0.0f, 0.0f, 1.0f));
plane.setColor(3, new Color3f(1.0f, 1.0f, 1.0f));
return plane;
}
Appearance createAppearance() {
Appearance appear = new Appearance();
Material material = new Material();
// make modifications to default material properties
appear.setMaterial(material);
return appear;
}
} // end of LitPlane class
public LitPlane2App (){
setLayout(new BorderLayout());
Canvas3D c = new Canvas3D(null);
add("Center", c);
BranchGroup scene = new BranchGroup();
TransformGroup objSpin = new TransformGroup();
objSpin.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
Alpha rotationAlpha = new Alpha(-1, 16000);
RotationInterpolator rotator =
new RotationInterpolator(rotationAlpha, objSpin);
rotator.setSchedulingBounds(new BoundingSphere());
objSpin.addChild(rotator);
scene.addChild(objSpin);
Shape3D plane = new LitPlane();
objSpin.addChild(new LitPlane());
AmbientLight lightA = new AmbientLight();
lightA.setInfluencingBounds(new BoundingSphere());
scene.addChild(lightA);
DirectionalLight lightD1 = new DirectionalLight();
lightD1.setInfluencingBounds(new BoundingSphere(new Point3d(0.0,0.5,0.0),0.1));
Vector3f direction = new Vector3f(0.0f, -1.0f, 0.0f);
lightD1.setDirection(direction);
lightD1.setColor(new Color3f(1.0f, 1.0f, 1.0f));
scene.addChild(lightD1);
SimpleUniverse u = new SimpleUniverse(c);
// This will move the ViewPlatform back a bit so the
// objects in the scene can be viewed.
u.getViewingPlatform().setNominalViewingTransform();
u.addBranchGraph(scene);
}
public static void main(String argv[])
{
new MainFrame(new LitPlane2App(), 256, 256);
}
}
