我是j3d中的完整n00b(但是是Java中的专家)。刚开始时,我遇到了透明度问题。我有一个简单的例子,绘制一个旋转的平面四边形(在显示背面时消失,因为我没有禁用背面剔除)。在Java中不能使用的简单透明度示例3D
随着Color3b和COLOR_3行未注释(以及对应的Color4b和COLOR_4行注释),我看到旋转的四边形,红色。但是,当我评论颜色3行并取消注释颜色4行时,即使alpha值设置为255(完全不透明),我也会看到黑色方块(相对于白色背景)。
我在做什么错? Google没有任何帮助,甚至java.forums.net上的Java3D论坛也没有什么帮助。 StackOverflow,救救我吧!您可以复制并通过下面的程序,运行它并查看会发生什么。
这里是我的规格:
的Java 6 OSX 10.5.5 J3D 1.5.2 JOGL 1.1.1
感谢,
--Rob
下面的代码:
import com.sun.j3d.utils.applet.MainFrame;
import com.sun.j3d.utils.geometry.ColorCube;
import com.sun.j3d.utils.universe.SimpleUniverse;
import java.applet.Applet;
import java.awt.*;
import javax.media.j3d.*;
import javax.vecmath.*;
public class Hello extends Applet
{
public Hello() throws Exception
{
setLayout(new BorderLayout());
GraphicsConfiguration config = SimpleUniverse.getPreferredConfiguration();
Canvas3D canvas3D = new Canvas3D(config);
add("Center", canvas3D);
BranchGroup scene = createSceneGraph();
scene.compile();
SimpleUniverse univ = new SimpleUniverse(canvas3D);
univ.getViewingPlatform().setNominalViewingTransform();
univ.addBranchGraph(scene);
}
public BranchGroup createSceneGraph() throws Exception
{
BranchGroup root = new BranchGroup();
// A white background.
Background bgd = new Background(1.0f, 1.0f, 1.0f);
root.addChild(bgd);
// This will spin the quad around
TransformGroup spin = new TransformGroup();
spin.setCapability(TransformGroup.ALLOW_TRANSFORM_WRITE);
root.addChild(spin);
// define the quad:
Point3d p1 = new Point3d(-0.5, -0.5, 0);
Point3d p2 = new Point3d(0.5, -0.5, 0);
Point3d p3 = new Point3d(0.5, 0.5, 0);
Point3d p4 = new Point3d(-0.5, 0.5, 0);
// colors
Color4b c = new Color4b((byte)255, (byte)0, (byte)0, (byte)255);
//Color3b c = new Color3b((byte)255, (byte)0, (byte)0);
QuadArray quads = new QuadArray(4,
GeometryArray.COORDINATES | GeometryArray.COLOR_4);
// GeometryArray.COORDINATES | GeometryArray.COLOR_3);
quads.setCoordinate(0, p1);
quads.setCoordinate(1, p2);
quads.setCoordinate(2, p3);
quads.setCoordinate(3, p4);
quads.setColor(0, c);
quads.setColor(1, c);
quads.setColor(2, c);
quads.setColor(3, c);
// Not sure if I need this. Doesn't seem to make a difference.
Appearance appearance = new Appearance();
TransparencyAttributes trans = new TransparencyAttributes();
trans.setTransparencyMode(TransparencyAttributes.BLENDED);
appearance.setTransparencyAttributes(trans);
// Create the shape...
Shape3D shape = new Shape3D();
shape.setGeometry(quads);
shape.setAppearance(appearance);
spin.addChild(shape);
Alpha rotationAlpha = new Alpha(-1, 4000);
RotationInterpolator rotator = new RotationInterpolator(rotationAlpha, spin);
BoundingSphere bounds = new BoundingSphere();
rotator.setSchedulingBounds(bounds);
spin.addChild(rotator);
return root;
}
public static void main(String[] args) throws Exception
{
Frame frame = new MainFrame(new Hello(), 256, 256);
}
}
工作。这意味着j3d中可能存在一个错误。我会报告它。 – user46028 2008-12-15 14:14:01