Hey everybody,

I have some 169 legacy HDAs used in an old Unity 5.5 project, from about 9 years ago. The first goal is to make the whole project work again in Unity 2021.3, then update it to a modern Unity 6.x.

The file Assets\Houdini\Scripts\HoudiniVersion.cs in the Unity project suggests it took advantage of Houdini 16.0.504.20 and Houdini Engine 3.0, API 57.

Loading the HDAs in Houdini 21 shows clear gaps in the graphs, I assume due to nodes that are not known to Houdini 21. Loading the same HDAs in Houdini 19 shows smaller gaps but still some.

I worked with SideFX support over the past few days to get a Houdini 16 up and running on my machine, so that I could see the HDAs in their original form and figure out how to replace the missing nodes with those available in H21. SideFX Support was kind enough to provide a number of H16 installers and the installation was successful. But we cannot find a solution to the licensing: the licensing system of the H16 era is not compatible with the current licensing system and SideFX cannot or will not create keys for H16.

Even if I manage to guess what the missing nodes were and replicate their functionality with H21 nodes, I currently cannot "certify" the output in H16 and H21 will be the same in terms of geometry and associated attributes.

I can create a number of scripts in both Unity and Houdini to do some error detection (to systematically flag missing nodes) and correspondence checks, i.e. that the geometry in Unity, given the HDAs parameters there, is similar to what is generated in Houdini (i.e. bounding box, points position). But it's not quite robust as a method.

Thoughts? Ideas? Suggestions?

Kind regards, Manu