Quote - I don't know the technology or what a height map is, but if a height map is a 2D image then it can be used commercially. However, neither you or the person who buys them can use them to create a 3D model. It is creating a 3D model that isn't allowed, no matter how it was created.  Otherwise every one could just say "I didn't use the original 3D geometry, the computer translated it to electrical signals and my printer used these electric signals and not the original 3D geometry to create the 3D model"  

PS: I don't know about legal stuff, so don't take my word for it.

 

Your comment illustrates the confusion.

Daz says, use our models to make renders which you can sell. They also say you cannot manufacture our models using any 3d manufacturing technique.

So a render that is used to produce a physical 3d model that is not the same as the original does not fall under any limitation. 

It the same as saying, "That indie movie you made with our content is very nice. Now we are going to charge a royalty for every sale that was made."

And then you say, "Well, that wasn't in your terms to start with. You said I can use the content commercially."

And then they say "We have a limitation of 100,000 impressions (or sales/use) of our figures before we start charging. The fact that we did not state this previously is irrelevant."