For rendering the world stuff :

		    Transform.setOrtho(-aspect, aspect, -1, 1, -10, 10);

For rendering the interface stuff :

	    	Transform.setOrtho(0,width,0,height,-10,10);


Set and get Ortho transformations (Identical for 2d and 3d)
	public static void setOrtho(float l, float r, float b, float t, float n, float f)
	{
		Matrix4f ortho = new Matrix4f();
		float[][] m = { {2.0f/(r-1),0,0,0},
				        {0,2/(t-b),0,0},
				        {0,0,-2/(f-n),0},
				        {-( (r + 1)/(r-l) ),-( (t+b)/(t-b)),-((f+n)/(f-n)),1} };
		ortho.setM(m);

		Transform.ortho = ortho;
	}

	public Matrix4f getOrthoTransformation()
	{
		Matrix4f transformationMatrix = getTransformation();

		Matrix4f cameraRotation = new Matrix4f().setCamera(camera.getForward(), camera.getUp());
		Matrix4f cameraTranslation = new Matrix4f().setTranslation(-camera.getPosition().getX(), -camera.getPosition().getY(), -camera.getPosition().getZ());

		return ortho.multiply(cameraRotation.multiply(cameraTranslation.multiply(transformationMatrix)));
	}

How I'm rendering and how I'm setting Interface sizes :

		InterfacePanel panel = new InterfacePanel();
		panel.setLocation(new Vector2f(50,50));
		panel.setBounds(new Vector2f(500,500));


And render :
	public void draw()
	{
		this.updateShaderForThisB();
		this.getMesh().draw();
	}

	public void updateShaderForThisB()
	{
		InterfaceShader shader = InterfaceShader.getInstance();
		shader.bind();
		shader.setColour(this.getActingColour());
		shader.setLocation(this.getLocation());
		shader.setSize(this.getBounds());
		shader.setGradient(this.getShouldGradient());
		Transform t = new Transform();

		shader.setViewMatrix(t.getOrthoTransformation());
		shader.updateUniforms();
	}

Mesh code :
	protected void generateMesh()
	{
		Vertex[] vertices = new Vertex[] {
				new Vertex(new Vector3f(location.getX(), location.getY(),zDepth)),
				new Vertex(new Vector3f(location.getX() + bounds.getX(), location.getY(),zDepth)),
				new Vertex(new Vector3f(location.getX(), location.getY() + bounds.getY(),zDepth)),
				new Vertex(new Vector3f(location.getX() + bounds.getX(), location.getY() + bounds.getY(),zDepth)),

		};
		int[] indices = new int[] { 0,1,2,
									1,2,3
		};

		mesh = new Mesh(vertices,indices);
	}