How to represent flow on a Curve mesh?

Troubleshooting graphics
1

Good day,

In my scene editor I have these Curve meshes I am using to represent connections in a control dialog.

I want to show the flow of the connection between these boxes.

Does anyone know how I can code a material for the Curve/Line that shows a dashed line with flow.

This is what it currently looks like:

image

What I want is something like this but will flow from left to right on the dashes of the curve:

image

2

Is that dashed line already drawn with a shader? If so I’d just offset the position along the line (used to determine if the dash is rendered or not) by time. I did flowing water like that (but it was offsettitng the texture coordinates)

Are you able to show how you create the curved line currently?

3

No the dashed line I edited in GIMP for representation for this forum topic.
This is my code:

    private Geometry drawLine2(Vector3f startPoint, Vector3f endPoint, float curveLength) {
        Vector3f[] controlPoints = new Vector3f[4];
        controlPoints[0] = startPoint;
        controlPoints[1] = startPoint.add(curveLength, 0, 0);
        controlPoints[2] = endPoint.subtract(curveLength, 0, 0);
        controlPoints[3] = endPoint;

        Spline spline = new Spline(Spline.SplineType.Bezier, controlPoints, 20, false);
        Curve curve = new Curve(spline, 40);
        Geometry lineGeom = new Geometry("line", curve);
        Material mat = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");  // create a simple material
        mat.setColor("Color", ColorRGBA.Yellow);   // set color of material to blue
        lineGeom.setMaterial(mat);
        lineGeom.getMaterial().getAdditionalRenderState().setLineWidth(1);

        return lineGeom;

    }
4

Whatever approach you use, you will probably need to set texture coordinates on the curve mesh.

…then without a custom shader, set a dashed texture and animate the texture coordinates.

5

Okay, how do I go about this?
Something like this?

setBuffer(VertexBuffer.Type.TexCoord, 2, BufferUtils.createFloatBuffer(vertexTexCoordinates));
6

Hi @ndebruyn , maybe you can find some useful examples here:

or maybe here:

1 Like
7

Thanks for sharing. I will look at it and see if I can use is.

1 Like
8

The example I use when wanting to know how to set things on a Mesh is Quad.java.

It’s not the most efficient way to set texture coordinates on a mesh if you are going to do it a lot… but it works fine and is simple to cut/paste that section of code. Especially if you already know you will have a fixed number of coordinates.

Edit: though if you find a material to do it then you only have to set the texture coordinates once and copying that code from Quad.java is the easiest way.

9

Thanks for all references and help by all.
I finally got a solution and just had to add the TextureCoords to the Curve mesh.
Using a material with a dashed texture and an animated UV movement to get the effect.

flow-brain

6 Likes
10

And here is an image of a more complex setup. Here you can see why I wanted to implement it.
The view now gives a beter and clear view of flow in the brain.
flow-brain-big

7 Likes