ZDoom

understood, thanks for the explanation.

The model pitch had several serious bugs in older versions. This is what you are experiencing. The main problem was that one function returned an inverted pitch. (ZDoom uses negative-up and positive-down, the model code was written for the inverse) And instead of doing it right there were several workarounds being added to make it look "right" for the inverted value but really only hid the problem for the narrow use cases that were considered.

When this was finally fixed it was inevitable that some stuff would break because it was just dead wrong in the engine's context.
So sorry, there is no way to make pitched models look right in 2.x.

It has been... difficult to make the jump to 3.x, because the performance of the 3.x family is abysmal on older hardware, which a team member is currently stuck with.

I cannot speak for the problem at hand, but on a related note: You should not target old versions unless you plan on also supporting old bugs. If a mod cannot run in newer GZDoom, then report it, because it might be a regression bug! While 100% backwards compatibility may not always be possible, compatibility regressions are taken seriously and GZDoom tries very hard not to break old mods.

Hello,

A project I am working is making use of models, some using USEACTORPITCH to angle them, however it seems that how the pitch value is interpreted between 2.x and 3.x is different.

In 2.x, the pitch rotates backwards: in 3.x, the pitch rotates forwards: We are trying to support as low a version as possible to keep mod compatibility as high as possible.

Is there a property I am missing to keep the pitch in sync across versions, or will we have to make a decision on which version family to support?