I got 2 anchors, I'd like to render an arrow object at one anchor and the direction of the arrow head to the other. I put some code, but it didn't work properly
private void drawLine(AnchorNode node1, AnchorNode node2) {
Vector3 point1, point2;
point1 = node1.getWorldPosition();
point2 = node2.getWorldPosition();
node1.setParent(mArFragment.getArSceneView().getScene());
//find the vector extending between the two points and define a look rotation
//in terms of this Vector.
final Vector3 difference = Vector3.subtract(point1, point2);
final Vector3 directionFromTopToBottom = difference.normalized();
final Quaternion rotationFromAToB =
Quaternion.lookRotation(directionFromTopToBottom, Vector3.up());
MaterialFactory.makeTransparentWithColor(getApplicationContext(), new Color(247, 181, 0, 0.7f))
.thenAccept(
material -> {
// create a rectangular prism, using ShapeFactory.makeCube()
// use the difference vector to extend to the necessary length
ModelRenderable model = ShapeFactory.makeCube(
new Vector3(.15f, .001f, difference.length()),
Vector3.zero(), material);
// set the world rotation of the node to the rotation calculated earlier
// and set the world position to the midpoint between the given points
Node nodeForLine = new Node();
nodeForLine.setParent(node1);
nodeForLine.setRenderable(model);
nodeForLine.setWorldPosition(Vector3.add(point1, point2).scaled(.5f));
nodeForLine.setWorldRotation(rotationFromAToB);
}
); // end rendering
ModelRenderable.builder()
.setSource(this, Uri.parse("model.sfb"))
.build()
.thenAccept(modelRenderable -> {
AnchorNode anchorNode = new AnchorNode(node1.getAnchor());
TransformableNode transformableNode = new TransformableNode(mArFragment.getTransformationSystem());
transformableNode.setParent(anchorNode);
transformableNode.setRenderable(modelRenderable);
transformableNode.setWorldRotation(rotationFromAToB);
mArFragment.getArSceneView().getScene().addChild(anchorNode);
transformableNode.select();
})
.exceptionally(throwable -> {
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(throwable.getMessage()).show();
return null;
});
}
You see the arrow is rendered but its direction is not correct.
Current situation. See image
I think you want the arrow on one anchor to point towards the other anchor - you can do this using 'setLookDirection' and a TransformableNode.
See below for an example:
var newAnchorNode:AnchorNode = AnchorNode(newAnchor)
var transNode = TransformableNode(arFragment.transformationSystem)
transNode.setLookDirection(Vector3(0f, 1f, 1f), Vector3.left())
transNode.renderable = selectedRenderable
transNode.setParent(newAnchorNode)
newAnchorNode.setParent(arFragment.arSceneView.scene)
See API documentation here:
https://developers.google.com/sceneform/reference/com/google/ar/sceneform/ux/TransformableNode
This is actually for Scenefrom 1.15 and the newer version 1.16 is now open source on GitHub, but I don't think a detailed API description exists so the above is still a good place to look at this time (May 2020).
You can use your own values for the two vector3's.
The first Vector3 is the point you want your renderable to 'look at', in your case the other anchor most likely, and the second Vector3 is the orientation of the renderable in the scene - i.e. if you want it upright, facing left etc.
One thing to be aware of, AFAIK, Sceeform is still designed for landscape mode so you may need to experiment to get the orientation the way you want if it not using landscape - for example the vector3.left() in the example above is to make a renderable appear upright on a portrait display.
Related
I want to do some geometric calculations in Java and found that Spatial4j should suit my needs.
I want to be able to compute stuff like whether two polygons overlap or what their bounding box is.
My thinking is that I need to create a polygon from a series of points.
To that end I have tested with this code:
Point point1 = shapeFactory.pointXY(0, 0);
Point point2 = shapeFactory.pointXY(5, 1);
Point point3 = shapeFactory.pointXY(3, 3);
Point point4 = shapeFactory.pointXY(0, 1);
List<Point> points = new ArrayList<>();
points.addAll(Arrays.asList(point1, point2, point3, point4));
So, I have my points now. How do I go about making a polygon (or for that matter any shape) from these points ?
I would think that shapeFactory.polygon() would create me a polygon but that throws me an UnsupportedOperationException. Any help ?
Alright, it seems that Spatial4j does not connect the points, so it is not a filled shape. Instead I relied on the Spatial4j implementation of JTS and that did the trick. (Spatial4j's polygon is not implemented).
JtsSpatialContextFactory jtsSpatialContextFactory = new JtsSpatialContextFactory();
JtsSpatialContext jtsSpatialContext = jtsSpatialContextFactory.newSpatialContext();
JtsShapeFactory jtsShapeFactory = jtsSpatialContext.getShapeFactory();
ShapeFactory.PolygonBuilder polygonBuilder = jtsShapeFactory.polygon();
// note due to it being a builder one needs to chain the points.
Shape shape1 = polygonBuilder.pointXY(4, 0).pointXY(3, 3).pointXY(1, 4).pointXY(0, 0).pointXY(4, 0).build();
Now doing for example shape.getArea() returns the surface area.
One can also create a Geometry from a Shape by doing jtsShapeFactory.getGeometryFrom(shape), which then returns a Geometry.
Note: Watch out with doing polygonBuilder.pointXY() even after calling build(). It will still append these points to whatever was chained to the builder before the build.
I have a very simple Java3D application, it contains two cubes, of which one of them orbits the other.
Like so:
As you can see, the default position for the viewing platform is from a 'kind of' birds eye view.
The code that looks like so
TransformGroup cameraTG = u.getViewingPlatform().
getViewPlatformTransform();
Vector3f translate = new Vector3f();
Transform3D T3D = new Transform3D();
translate.set( 0.0f, 0.0f, 20.0f);
T3D.setTranslation(translate);
cameraTG.setTransform(T3D);
My question is, is it possible to set the viewing platform to track the larger cube (the cube that rotates around the smaller square). Or more straight forward, is it possible for the viewing platform to rotate around a given body?
More information:
My goal is to have a miniature solar system, containing the Sun, Earth and moon. And I would like to view it from the point of view of the earth (almost like a view from the ISS)
Any help or pointers would be fantastic. Please feel free to ask for more information if needed.
You have a nice example here http://java3d.nl/Tutorials/Java/Java3d/Controlthecamera_12.php
The original http://java3d.nl website is no longer available, but you can still use the cached version from the Internet Archive: https://web.archive.org/web/20131218022035/http://java3d.nl/Tutorials/Java/Java3d/Controlthecamera_12.php
this.camera = this.universe.getViewingPlatform().getViewPlatformTransform();
//Add things to the universe
this.root = new BranchGroup();
this.root.addChild(new ColorCube(0.2));
this.universe.addBranchGraph(root);
My idea is like this:
BranchGroup b=new BranchGroup();
b.addChild(cube);
b.addChild(camera);
then in a loop where you rotate the block:
while(true) {
... b.getChild()......... etc
apply transform
}
or more specifically
for(j=0; j<group.numChildren(); j++) {
Node ni=group.getChild(j);
if(ni instanceof TransformGroup) {
Transform3D tdi=new Transform3D();
TransformGroup tgi=(TransformGroup)group.getChild(j);
tgi.getTransform(tdi);
Transform3D rotation = new Transform3D();
rotation.rotX(Math.toRadians(0.001*i));
tdi.mul(rotation);
tgi.setTransform(tdi);
}
}
There is a simpler solution. Instaed of trying to control the viewer gaze using angles and rotation, you can merely say what 3D point to look at. In the ViewingTransform, you can call "lookAt(...)":
TransformGroup viewingTransformGroup = simpleUniv.getViewingPlatform().getViewPlatformTransform();
Transform3D viewingTransform = new Transform3D();
Point3d eye = viewersLocation;
Point3d center = gazePoint;
Vector3d up = new Vector3d(0,1,0); //assumes +y-axis points up
viewingTransform.lookAt(eye, center, up);
viewingTransform.invert();
viewingTransformGroup.setTransform(viewingTransform);
Related to: How can I share DomainAxis/RangeAxis across subplots without drawing them on each plot?
Note - I originally wrote this up as a question, and then realize my mistake, so I decided to just share the knowledge since I already had this all typed out.
In JFreeChart, there are two plot types that share an axis range and draw only one axis, while sharing that information with their subplots. These are CombinedDomainXYPlot and CombinedRangeXYPlot. I will focus on CombinedDomainXyPlot, but the other should be identical for the purposes of this question. Looking at the draw code we see:
...
setFixedRangeAxisSpaceForSubplots(null);
AxisSpace space = calculateAxisSpace(g2, area);
Rectangle2D dataArea = space.shrink(area, null);
// set the width and height of non-shared axis of all sub-plots
setFixedRangeAxisSpaceForSubplots(space);
// draw the shared axis
ValueAxis axis = getDomainAxis();
RectangleEdge edge = getDomainAxisEdge();
double cursor = RectangleEdge.coordinate(dataArea, edge);
AxisState axisState = axis.draw(g2, cursor, area, dataArea, edge, info); // <- draw the share axis
if (parentState == null) {
parentState = new PlotState();
}
parentState.getSharedAxisStates().put(axis, axisState); // <- put the state of the shared axis in a shared object
// draw all the subplots
for (int i = 0; i < this.subplots.size(); i++) {
XYPlot plot = (XYPlot) this.subplots.get(i);
PlotRenderingInfo subplotInfo = null;
if (info != null) {
subplotInfo = new PlotRenderingInfo(info.getOwner());
info.addSubplotInfo(subplotInfo);
}
plot.draw(g2, this.subplotAreas[i], anchor, parentState, subplotInfo); // <- pass this shared object to the subplot draw function.
}
...
in the subplot (XYPlot) draw method, we see:
domainAxisState = (AxisState) parentState.getSharedAxisStates().get(getDomainAxis());
The getDomainAxis() method is calls getDomainAxis(0), which is:
public ValueAxis getDomainAxis(int index) {
ValueAxis result = null;
if (index < this.domainAxes.size()) {
result = (ValueAxis) this.domainAxes.get(index); //<- try to find this domain axis in self
}
if (result == null) { //<- if not found in self ...
Plot parent = getParent();
if (parent instanceof XYPlot) {
XYPlot xy = (XYPlot) parent;
result = xy.getDomainAxis(index); //<- ...try to get from parent
}
}
return result;
}
Here, parent is the CombinedDomainXYPlot. This will return a reference to the domainAxis from CombinedDomainXYPlot, to be used for retrieving the axisState from the parentState object. It seems the getDomainAxis() method is not used for getting an axis to draw, only for getting a reference to it for other purposes.
I was looking into this because I was trying to use the same technique to pass multiple shared axes to multiple different groups of plots, but only draw them once. This technique seems to work, but there are glitches right now in that zooming the plots that only get state information does not update the main plot that has the axis... Working on it, but hopefully this information is useful to someone down the line.
Thanks,
Igor
Answered in question post.
As state above, the getDomainAxis() method in XYPlot is apparently not used for getting an axis to draw, only for getting a reference to it for other purposes. So if you override this method to link to another axis and put it's state information into a shared object, this state info will be shared between plots.
I'm using Java3d (VERSION 1.6) and am trying to read all polygons from any object.
I loaded one object using following code:
private BranchGroup loadObj(String p) {
BranchGroup objRoot = new BranchGroup();
TransformGroup tg = new TransformGroup();
Transform3D t3d = new Transform3D();
t3d.setScale(0.3);
Matrix4d matrix = new Matrix4d();
t3d.get(matrix);
try
{
Scene s = null;
ObjectFile f = new ObjectFile ();
String basepath = new File(p).getAbsolutePath();
System.out.println(basepath);
f.setBasePath(basepath);
f.setFlags (0);
s = f.load (s1);
s.getSceneGroup().setBoundsAutoCompute(true);
tg.addChild (s.getSceneGroup ());
objRoot.addChild(tg);
bounds.add(objRoot.getBounds());
objRoot.compile();
}
Now I like to read the computed polygons from that BranchGroup or Scene Object and put each in a class of mainly an array of Point3d's. With that class I build some algorithms to search for specific points and stuff. So how would I get these polygons?
The reason I need it is because I'm trying to "walk" over an uneven surface. I can't use BoundingBoxes or spheres, for that is not precise enough. I would appreciate a different solution as well!
EDIT:
With the help of gouessej I got so far:
try
{
Scene s = null;
ObjectFile f = new ObjectFile ();
String basepath = new File(p).getAbsolutePath();
System.out.println(basepath);
f.setBasePath(basepath);
f.setFlags (ObjectFile.TRIANGULATE);
String s1 = p;
s = f.load (s1);
BranchGroup branch = s.getSceneGroup();
branch.setBoundsAutoCompute(true);
Shape3D shape = (Shape3D)branch.getChild(0);
Geometry g = shape.getGeometry();
TriangleArray ta = (TriangleArray)shape.getGeometry();
System.out.println(ta.getVertexCount()); // Prints around 95.000, sounds about right
System.out.println(ta.getVertexFormat()); // prints 387
double[] coords = ta.getCoordRefDouble(); // line: 526; Here it throws the exception
System.out.println(Arrays.toString(coords));
tg.addChild (branch);
objRoot.addChild(tg);
bounds.add(objRoot.getBounds());
System.out.println();
objRoot.compile();
}
But on the line ta.getCoordRefDouble(), it throws me an Exception:
Exception in thread "main" java.lang.IllegalStateException: GeometryArray: cannot access individual array references in INTERLEAVED mode
at javax.media.j3d.GeometryArray.getCoordRefDouble(GeometryArray.java:5755)
at com.object.simpleTest.Test1.loadObj(Test1.java:526)
at com.object.simpleTest.Test1.<init>(Test1.java:428)
at com.object.simpleTest.Test1.main(Test1.java:686)
What does it mean and how to fix it?
At first, Java 3D is NOT dead as you can see here (please edit your question).
Secondly, you can look at the Java documentation of the class ObjectFile. I advise you to use the flag "TRIANGULATE" to be sure to get a polygon array containing only convex polygons to ease your computations.
The branch group of your Scene object contains one Shape3D object. This Shape3D object contains a Geometry object, it stores your polygons. The source code of ObjectFile is here. Look at this line.
Edit.: You can get the BranchGroup of your scene by calling Scene.getSceneGroup(). You can see that the group is added into the scene here. Call Group.getAllChildren(), loop on all children, use instanceof to check whether a child is an instance of Shape3D. For each Shape3D, call getGeometry() or getAllGeometries(). The geometry should be a GeometryArray, maybe a TriangleArray. getCoordRefBuffer() might not work exactly in the same way in Java 3D 1.6 because we removed J3DBuffer, use getCoordRefDouble(), getCoordRefFloat() or any variant of getCoordinate() or getCoordinates(). Please ensure that you use Java 3D 1.6 so that we are talking about the same code and the same version. Older versions are obsolete and unmaintained.
Edit.2: Rather call getInterleavedVertices() as its name implies if the vertices are interleaved. Keep in mind that it might contain the normals too (in first position), not only the vertex coordinates (in second position):
nx ny nz vx vy vz
i want to trace the trajectory between differents points
for the test i creat points and try to link between these points
this is my code
OpenStreetMapLayer osm = new OpenStreetMapLayer();
map.addLayer(vectorLayer);
List<Point>points= new ArrayList<Point>();
Point point = new Point(44.272872,4.27826);
Point point2 = new Point(-55.272873,5.3873837);
Point point3 = new Point(5.272873,54.3873837);
points.add(point);
points.add(point2);
points.add(point3);
Point[] coord=new Point[points.size()];
points.toArray(coord);
polyline.setPoints(coord);
vectorLayer.addComponent(polyline);
Style defaultstyle = new Style();
/* Set stroke color to green, otherwise like default style */
defaultstyle.extendCoreStyle("default");
defaultstyle.setStrokeColor("#0000ff");
defaultstyle.setStrokeWidth(3);
defaultstyle.setFillColor("#adfffc");
defaultstyle.setFillOpacity(0.4);
// Make borders of selected graphs bigger
Style selectStyle = new Style();
selectStyle.setStrokeWidth(5);
StyleMap stylemap = new StyleMap(defaultstyle, defaultstyle, null);
// make selectStyle inherit attributes not explicitly set
stylemap.setExtendDefault(true);
vectorLayer.setStyleMap(stylemap);
but when i execute my code i get just a point i've asked they told me this point is the point of cordinate(0,0)
this is the screen catch of the set of points without ZOOM (the blue point)
http://img4.hostingpics.net/pics/810776sss.png
and this is the MAX ZOOM
http://img4.hostingpics.net/pics/122823ert.png
i want to know if it is a probleme of scale or what?
thanks in advance
You are using https://en.wikipedia.org/wiki/EPSG:4326 coords but OSM is using https://wiki.openstreetmap.org/wiki/EPSG:3857. The first one is in abs(180,90) where the second one is in in abs(6356752,6378137). so your points are basically at the center in spherical mercator and zooming very close will give your result. you have to convert your data e.g. using geotools