I'm working on a net table design and want to use a cracked glass look for the top but I'm darned if I know how.

can you show a reference picture of what you are wanting??

Heres what I trying for.

http://www.glassical.com/Customer's%20...le%20circle.jpg

I suppose the cracks cost extra.

That's a bit small.... but if I were going to leap into that I'd start by modeling a slab of glass in the conventional manner and then using a material with one of the cellular noise combiners on the bottom side and possibly set to "bump".

The cracks are so numerous there that it's almost like frosted glass. It's opaque enough to clearly show the shadow falling on it. And yet there seem to be no cracks on the top surface.

http://www.glassical.com/crackle_closeup_10.jpg

Heres a better shot

That pattern looks very, very much like one of the cellular noise combiner variants.

Click to view attachment

Thanks very much will give it a try and let you know how it comes out.

Click to view attachment
I had to try but this is the best I could get. I tried a material first and wasn't happy with my first attempt so I went for doing it all with an extruded grid. Still not really capturing the essence of cracked glass though. Maybe a combination of the two would give better results.

I think that's really close. I think one part of the cracked glass in the photo was that the vertical crack surfaces were quite reflective.

Still pretty close, how did you do it with the extruded grid?

1) Create a grid.
2) Move the CPs around to simulate cracked glass.
3) Select all CPs and extrude to give the glass thickness.
4) Edit surface properties to give suitable colour, reflection, refraction, etc.

This is not the ideal method that I was hoping for. It uses a lot of geometry and internal patches, which is normally something that you want to avoid.
Maybe someone will work out a material that does the job.

In the meantime try this:
Click to view attachment