I'm trying to create a rock formation similar to

This is what I've kind of came up with for one of the chunks





As you can see the edges are more rounded than I would like. Is there a node I can use to get some hard edges like the stacking in the example image?

Hello

Apparently it is good practice before exporting models to game engines to apply a ‘normal’ node to your model. It contains a slider that allows you to set the hardness/softness of the edges of your model. Apparently, in the view port, smooth shading works on points whilst the normal node works based on vertices (I believe its that way around) which is what games engines work with so even if it looks right in the view port, still a good idea to apply the node.

I think there is a sidefx tutorial on this somewhere.

If you'd like to make only specific edges hard edges, you can specify an edge group in the Normal SOP and set the cusp angle low enough (e.g. 0) that they'll all be hard.

Side note: As of Houdini 16.0, the viewport computes vertex normals with a cusp angle of 60 degrees by default, (equivalent to setting Weighting Method to Each Vertex Equally). You can change this in the display options under the Geometry tab.

You could also use the facet sop like this…

To create the rock formation as shown it might be better to go by the displacement shader method as you would need a gazillion polys to get the details you see in that pic. Although most of the surface is flat, you need to get your polygon to the smallest chip on that rock.