How is BBTilt in 2.49b different from 2.46?

So, I’ve been following the “Realistic Smoke” tutorial from Blenderart Mag 16, and I specifically remember BBTilt working with 2.46 as it is described in the tutorial.

Step 03: Click on “BBTilt” (meaning Billboard Tilt). This parameter is used to rotate the billboard according the camera view and particles’ age.

Step 04: Press CTRL key, and click with the left mouse button around the coordinates 0.0/0.0, adding a new point (use the right mouse button if “Select with Left mouse button” is set in your Blender’s preferences).

Step 05: Once again, create a new point around the frame 200 with a value of 2.0.

That makes the particles tilt a certain amount based on their lifetime.

In 2.49b, performing the same steps as above does not give the same result. The particles stay at the same Tilt value until frame 200 (based on the tutorial, it is the frame when particle emission stops) and then they rotate until the Tilt value reaches 1.0 and then they stop rotating.

I don’t know if this has anything to do with Time as it is implemented for particles, but according to the Manual, BBTilt “change[s] the behavior of the particles during their lifetime.” So, I would expect the billboards to be rotating during their lifetime, and not just after emission has stopped. Any ideas? Thanks!

have you also checked the render? I had the same problem here, but the Billboards were just rotationg fine in the render (this was 2.48b). It was just in the preview that things didn’t work. Flushing the cache and baking again sometimes helps…sometimes it doesn’t … :confused:

Well, what do you know…That really seems like a bug. It WAS rotating in the render, but at some weird ti e during the preview. How silly. Thanks, laune!