2D HUD deformations in real time

I create a loading screen using simple graphic elements. For example:

        rotatingRingPicture = new Picture("Ring");
        rotatingRingPicture.setImage(assetManager, "Textures/Loading.png", true);
        int w = settings.getWidth()/8;
        int h = w;

I show to the user a rotating loading ring until the game scene is uploading in a separate thread.
I also want that the words: LOADING… PLEASE WAIT change their transparency from min up to max in according to a sinus dependency.
I could create it using LibGDX or Processing but in JMonkey engine I can not find methods to:

  1. change the transparency of a gui-child
  2. change the offset/anchor of a gui-child to rotate it around its center point.

How can I perform this actions? I need to change the guiChild transparency and rotate the guiChild around its center point.

Set the material color to something transparent. Set the material’s blend mode to alpha (see tutorials for how to do that).

Put it under a node that you will rotate and on the Picture call:

Edit: it sounds like maybe you are new to scene graphs… in which case this might help:

@pspeed thanks, I created a node and added the rotating ring to it and it works. In simpleInitApp():

        rotatingRingPicture = new Picture("Ring");
        rotatingRingPicture.setImage(assetManager, "Textures/Loading.png", true);
        int w = settings.getWidth()/12;
        int h = w;
        rotatingRingPicture.setLocalTranslation(-w/2, -h/2,0);
        rotatingRingNode = new Node();
        rotatingRingNode.setLocalTranslation(settings.getWidth()/2, settings.getHeight()/4, 0);

in simpleUpdate(float):

             Quaternion rotation = new Quaternion();

About changing transparency. I have not understood yet how should I use materials with GUI-children.

In general, except just "LOADING… " text and etc i would suggest you doing all in Shader.

Transparency / offset / rotation / etc all can be done in shader easly.

Here is simple example that all it do is made in shader:


GUI children are not different than regular scene graph children. A Picture is just a hacky subclass of Geometry… it has a Material like any other Geometry.

It uses JME’s regular Unshaded.j3md material.

At the point someone is still learning how to use a scene graph, “easily” is probably not the term I would use for diving into shaders.


@pspeed I didn’t know that, thanks