[SOLVED] Vertex buffer not uploading to GPU when expected

Troubleshooting graphics
1

What circumstances would cause a vertex buffer to not upload to the gpu when its mesh gets rendered?

I’m trying to bind an opencl buffer to a mesh’s color buffer, and that requires the color buffer be uploaded to the gpu first. No matter how long I wait, the color buffer never gets uploaded, so when I attempt to bind, an error occurs. I perform the exact same operation at the same time on the mesh’s position buffer, and that binds with no issues.

This is how I set up the vertex buffers in the mesh:

int cap = getCapacity(); // get number of verts
FloatBuffer pb = BufferUtils.createVector3Buffer(cap);
FloatBuffer cb = BufferUtils.createFloatBuffer(cap * 4);
MeshUtils.initializeVertexBuffer(this, Type.Position, VertexBuffer.Usage.Stream, VertexBuffer.Format.Float, pb, 3);
MeshUtils.initializeVertexBuffer(this, Type.Color, VertexBuffer.Usage.Stream, VertexBuffer.Format.Float, cb, 4);
updateCounts();
updateBound();

public static VertexBuffer initializeVertexBuffer(Mesh mesh, Type type, Usage usage, Format format, Buffer data, int components) {
    VertexBuffer buf = mesh.getBuffer(type);
    if (buf != null) {
        buf.updateData(data);
    } else {
        buf = new VertexBuffer(type);
        buf.setupData(usage, components, format, data);
        mesh.setBuffer(buf);
    }
    return buf;
}

About two frames after initializing the vertex buffers, I initialize opencl bindings:

clPosBuffer = context.bindVertexBuffer(getBuffer(Type.Position), MemoryAccess.READ_WRITE);
// vvv program fails here vvv
clColorBuffer = context.bindVertexBuffer(getBuffer(Type.Color), MemoryAccess.READ_WRITE);

The program throws this exception:

SEVERE: Uncaught exception thrown in Thread[jME3 Main,5,main]
java.lang.IllegalArgumentException: vertex buffer was not yet uploaded to the GPU or is CPU only
	at com.jme3.opencl.lwjgl.LwjglContext.bindVertexBuffer(LwjglContext.java:156)
	at codex.vfx.particles.gpu.GpuParticleMesh.initOpenCL(GpuParticleMesh.java:131)
	at codex.vfx.particles.gpu.GpuParticleGeometry.updateLogicalState(GpuParticleGeometry.java:37)
	at com.jme3.scene.Node.updateLogicalState(Node.java:239)
	at com.jme3.app.SimpleApplication.update(SimpleApplication.java:265)
	at com.jme3.system.lwjgl.LwjglAbstractDisplay.runLoop(LwjglAbstractDisplay.java:160)
	at com.jme3.system.lwjgl.LwjglDisplay.runLoop(LwjglDisplay.java:225)
	at com.jme3.system.lwjgl.LwjglAbstractDisplay.run(LwjglAbstractDisplay.java:242)
	at java.base/java.lang.Thread.run(Thread.java:833)

I have tried waiting longer between initializing vertex buffers and initializing opencl bindings, but that had no impact. I have also tried using the texture coordinate vertex buffer instead of the color vertex buffer, but that had no impact either.

2

Never mind, got it fixed. The color vertex buffer did not get uploaded because the inColor attribute was not used for anything besides a varying in both the vertex and fragment shaders.

I will leave this post here in case someone else has trouble with this issue.

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