Trouble with a custom mesh

Troubleshooting General Help
1

Hi,



I’ve a small problem with a custom mesh.



I use a library to read PLY files, and build a Mesh. I read the data, fill float array, give them to a new mesh. I can render the mesh, it works perfectly.



Now, in another part of my program, I need to access those buffer, read them, and change them. Trying to access the position buffer give me this:

Exception in thread "main"
java.lang.UnsupportedOperationException at
java.nio.FloatBuffer.array(FloatBuffer.java:957)


[java]VertexBuffer v = mesh.getBuffer(Type.Position);
Buffer b = v.getData();
System.out.println(b.hasArray());[/java]

This print false.

Any idea ?
2

More exactly:

[java]Mesh mesh = new Mesh();

mesh.setBuffer(Type.Position, 3, BufferUtils.createFloatBuffer(points));

float[] array = (float[]) mesh.getBuffer(Type.Position).getData().array();[/java]



[java]Exception in thread "main" java.lang.UnsupportedOperationException

at java.nio.FloatBuffer.array(FloatBuffer.java:957)

at java.nio.FloatBuffer.array(FloatBuffer.java:257)[/java]



What is wrong with that ?

3

From: http://docs.oracle.com/javase/1.5.0/docs/api/java/nio/FloatBuffer.html#array()

float[] array() Returns the float array that backs this buffer (optional operation).



Note: the optional operation part.



Also: Invoke the hasArray method before invoking this method in order to ensure that this buffer has an accessible backing array.



The problem:

Direct buffers (ie: native buffers) do not support modifying the underlying array directly because it is native memory and not Java managed memory. You have to go through the float buffer interface.

4

Well, thank you sir ! :slight_smile: