BUG: Simple Expressions

Hi,

I tried 2D Track to 3D Nodal Pan Example.comp via Vfxpedia.com. But it doesn't work with Fu7.

2D Track to 3D Nodal Pan
These expressions on a Camera3D's rotation inputs will turn a 2D track (called "Tracker1" in this example) into a nodal pan. Works for pan and tilt moves. Focal length can be set arbitrarily. Same for the film back, although the ratio of horizontal and vertical aperture has to match the image aspect ratio!

Code: Select all

-- X Rotation:
math.atan(25.4 * ApertureH * (Tracker1.SteadyPosition.Y-0.5) / FLength) * (180 / math.pi)
-- Y Rotation:
-math.atan(25.4 * ApertureW * (Tracker1.SteadyPosition.X-0.5) / FLength) * (180 / math.pi)

"Tracker1.SteadyPosition" doesn't work. Why? It works fine with Fu6.4.

Where is BugReporter?

I wrote that expression. nice to hear it's of use to you! or at least "was".

the only thing I can think of... is there a tracker called "Tracker1" in your comp?

Hi Stefan,

Thank you for your expression. I like it and very useful for me.

Yes, there is "Tracker1". Because It works fine on Fu6.4.

Ouch, can't get it to work either! And when I connected a Transform's center to "Tracker1.SteadyPosition" via an expression, Fusion simply closed itself after going back and forth between frames for a while.

Fusion's Tracker has some outputs. We can use them in expression or connect to...
(Tool Reference p.373)
I tried to test other output. Yes, Fusion just closed. Tracker's outputs no longer function.

I gave up to use Fu7(eye's Fu7 and BMD Fu7.7). I decided to go back to Fu6.4.

Why is Blackmagic indifferent to this topic.

This bug have not been corrected in 7.7. I converted this simple expression to Expression modifier.