Develop Reference

How do I make a fixed size grid-pane in JavaFX Scene Builder?

I'm trying to make a centered grid pane in the JavaFX scene builder which stays a fixed size. I'm having a hard time doing this myself. Anything I can do?
I'm trying to accomplish something like this:

You can use stackpane as parent of your gridpane

how to achieve resizability in javafx?

I have an AncharPane in which all components are placed/designed using Fxml but the problem is, when the frame resize all components are stick with its current position.

With AnchorPane, you can't get automatic resizing unless you have to resize your views one by one in the controller/code.
If you want autoresize, use BorderPane, VBox or HBox.

If you're using scene builder you can achieve this by selecting the component you'd like to make resizable, then go under layout and set the constraints.
You can also achieve this in your Controller class like this:
AnchorPane.setTopAnchor(yourTextField, 35);
AnchorPane.setLeftAnchor(yourTextField, 27);
AnchorPane.setRightAnchor(yourTextField, 120);
I used a TextField for this example, but you can do it with other components.

If the AnchorPane has a border and padding set, the offsets will be measured from the inside edge of those insets.
To autoresize I recommend BorderPane. You can also use VBox and HBox to organize you Scene.

How to overlay GUI over 3D scene in JavaFX?

I have a 3D scene in JavaFX and need to overlay GUI over the 3D scene. I have tried adding buttons and text to the scene but they always appear in the 3d view as 3D objects. I have looked around and haven't found how to do it. The only workaround would be creating a whole new window and putting the settings there but that isn't an option in this case. Thanks for the help!!
Something like this
Or this

The best solution for what you are looking for is the SubScene, a built-in JavaFX container:
The SubScene class is the container for content in a scene graph. SubScene provides separation of different parts of a scene, each of which can be rendered with a different camera, depth buffer, or scene anti-aliasing. A SubScene is embedded into the main scene or another sub-scene.
If you have a look at the 3DViewer project, you'll find it is like the pictures you have posted:
You can find a small sample of how to add a subScene to a regular scene in this question.

How to keep JavaFX MenuBar in the top part of the window

I'm trying to make an window, where I have StackPane as root and I want to add MenuBar to this window. However MenuBar is in the center of the screen and I want to keep it in the top part of the window as in normal Windows applications.
root = new StackPane();
root.getChildren().add(new MenuBar());
this will show window like this
http://i61.tinypic.com/2pzblmo.jpg
Thanks you for your advice!

I would say StackPane is not suitable for making a GUI including a menubar.
StackPane will just put the controls you add to it one on top of the other.
In java docs you can find:
"StackPane
The StackPane layout pane places all of the nodes within a single stack with each new node added on top of the previous node. This layout model provides an easy way to overlay text on a shape or image or to overlap common shapes to create a complex shape. Figure 1-6 shows a help icon that is created by stacking a question mark on top of a rectangle with a gradient background.
"

JavaFX embed scene in scene

I have an application that uses a javafx Scene to render something, and I want to put that rendering into some GUI that I made, also in javafx. How would I do that?
Basically is there some container I can put a scene into and then put that container into the GUI.
Sorry if it's a newbie question, I am new to JavaFX

Java 8 has a SubScene, for which some possible uses (from the javadoc) are:
The SubScene class is the container for content in a scene graph.
SubScene provides separation of different parts of a scene, each of
which can be rendered with a different camera, depth buffer, or scene
anti-aliasing. A SubScene is embedded into the main scene or another
sub-scene. Possible use cases are:
Mixing 2D and 3D content
Overlay for UI controls
Underlay for background
Heads-up display
A SubScene is just a Node, so you can place it in the scene graph of an existing scene wherever you want. An example of SubScene usage is in the answer to: How to create custom 3d model in JavaFX 8?
Generally SubScenes are for mixing 2D and 3D content. If you are not doing that, then SubScenes probably don't apply to your situation and Uluk's answer will better serve your needs.

The scene has only a top parent node as a root. You can get it and to put into another scene.
((Pane) scene2.getRoot()).getChildren().add(scene1.getRoot());