JavaFX 3D: Transforming Cylinder to defined start and end points

问题

Suppose that I want a Cylinder to start in some 3D point and to end in some other 3D point.

As far as I know, the way to do that, is to compute the Euclidian distance between the 2 points and to create a Cylinder with the same length. Then, the cylinder should be translated and rotated, such that it really starts at the start point and ends at the end point.

I get messed up with these transformation and do not succeed to place the Cylinder in its correct place.

Could you please share some code snippet of implementation of the function:

void createCylinder(Group group, double p1X, double p1Y, double p1Z, 
                                 double p2X, double p2Y, double p2Z)

回答1:

Answering myself as I've found a solution.

Found a working nice snippet here: http://netzwerg.ch/blog/2015/03/22/javafx-3d-line/

Here is the code, it's simple:

public Cylinder createConnection(Point3D origin, Point3D target) {
    Point3D yAxis = new Point3D(0, 1, 0);
    Point3D diff = target.subtract(origin);
    double height = diff.magnitude();

    Point3D mid = target.midpoint(origin);
    Translate moveToMidpoint = new Translate(mid.getX(), mid.getY(), mid.getZ());

    Point3D axisOfRotation = diff.crossProduct(yAxis);
    double angle = Math.acos(diff.normalize().dotProduct(yAxis));
    Rotate rotateAroundCenter = new Rotate(-Math.toDegrees(angle), axisOfRotation);

    Cylinder line = new Cylinder(1, height);

    line.getTransforms().addAll(moveToMidpoint, rotateAroundCenter);

    return line;
}

来源：https://stackoverflow.com/questions/38799322/javafx-3d-transforming-cylinder-to-defined-start-and-end-points

标签

javafx

javafx-8

javafx-3d