If the camera focal length is animated, the change in values are not written in the exported .chan file. The fov values are taken from the frame the chan file was exported at only.
I'll look into this.
Just had a look at the fov export in Terragen 3 and the same bug is there (won't write animated fov to a chan file)
Which parameter has the animation keys on it?
just making an example file to send to you, but in the process, see what you mean :-)
I was animating the focal length of the camera, but you've got to set a key for the "use horizontal fov" parameter as well for every key of your focal length animation?
I think the bug is that the export code asks the FOV parameter (either horizontal or vertical) what its key frames are doing, but it's not smart enough to know about the animation of the focal length.
I guess it would be more inuitive to read the focal length keys, but works for now if you remember to set the corresponding fov key