Inventor HSM Pro supports machining directly off STL files by using the Load model function in the Job setup.
Load model button
Clicking the Load model button lets you browse for a Stereolithography (*.STL) file to be imported. When the Inventor part or assembly is saved, the STL data is saved internally in the part or assembly.
With an STL loaded, you can click the Unload model to remove the STL data and load a different file.
Since STL's are saved in different units depending on the generating software, it may be necessary to scale the STL. To do this you can specify the scale by selecting one of the available units or entering a custom scale.
A scale of 0.001 converts from millimeters to meters
With an STL model loaded, a preview of the STL is shown in the graphics window and the automatic stock feature is enabled
Automatic Stock on an STL
Heights "From Model Top/Bottom" and "From Stock Top/Bottom"
Parallel toolpath on an STL