mouse capture in viewport

Hello,
I'm trying to show the x,y,z position of the mouse within the helix3d viewport. I was wondering if there are any examples or samples, that show how to do this?

I'm building a 3D level editor, with a 3D grid, used for positioning objects. When the mouse moves through the grid, I want transparent planes to light up each side of the cube which the mouse is over, within the grid.

So far I have the X & Y mouse coordinates of the HelixViewport3D. I forget how to get the z coords. It's Camera lookat direction multiplied by something.. Arg, can't remember. Help!

Thanks,
Alex

See the CurrentPosition property in the HelixViewport3D control.
Or use the Viewport3DHelper.Point2DToRay3D function. You can then find the intersection of the Ray3D and a Plane3D.
See also the "VoxelDemo" in the "ExampleBrowser".