Which Spatial Adjustment Method?

[Oliver_Burdekin]

I have a CAD drawing with no world file or projection associated. I do have grid lines included in the drawing. I am using the spatial adjustment tool to relocate the drawing as when brough into Arc the coordinates are based on the CAD file (nonsensical in a geographic sense). The spatial adjustment tool offers three options for tranformations:

Affine
Similarity
Projective

Having read the docs it strikes me projective would be most appropriate (maintains shapes) but would like to know if this is suitable.

[DanPatterson_Retired]

Affine, if you just have a shift, rotation and equal scaling in the X, Y direction..  In other words, you just want to move the data to a new location

[Oliver_Burdekin]

Thanks Dan. In what use cases would the other two suitable? I'm trying all three with these particular data just to get a better feel for the differences.

[AdrianWelsh]

Oliver, in your own testing, what have you found with these different adjustments?