PSA: Fusion 17.1 introduced some 3D rendering changes

Fusion 17.1 introduces some new bugs and features that aren't in the release notes but will affect renders without throwing any errors or warnings.

1) Mapped GL materials using scalar inputs now use the alpha of incoming textures, not red, as in previous versions and the SW renderer. So if you have "roughness" or "reflection intensity" or similar inputs mapped, they will render differently than they did in 17.0 and earlier and they will render differently than the SW renderer does in 17.1.

2) Directional lights now have shadows, and they are on by default. Previous versions of Fusion did not support shadows from directional lights, and comps and macros from previous versions when loaded into 17.1 do not have those shadows disabled, so renders will look different than they did in previous versions. Directional lights are common in 3D text presets, so be advised that they might look different now.

EDIT: I would like to think it is probable that these behaviors would change for future versions, if for no other reason than that GL and SW renderers should have compatible materials, so materials you make in 17.1 might be broken in 17.2, for instance.

Wow that's crazy! Thank you for pointing this out. I always expected we would see a bigger overhaul to the 3D system more or less from scratch, but seems like this will stay the base if they start to add shadows.
Doesn't have to be bad, but probably indicates no hydra viewport in active development.
Still great that it got shadows. Hopefully all lights will soon be able to do (soft) shadows.

I have to do some testing tomorrow if the software renderer bug has been squashed as well.

There's some new bugs in 3Bol, 3CT, 3Ca, and 3Ph, too, so don't move to 17.1 or 17.1.1 if you're doing 3D work.

Thanks for the heads up on this, Chad. Odd the release notes say nothing about these changes...
For me, having directional lights cast shadows is a good thing; but being informed would have been a bonus especially if they're on by default

One of the bugs I've just experienced is the ChannelBoolean (3Bol) doesn't output anything when set to Position.
Works in 17.0