Trimming 3D objects on timeline

Hello guys

My first mid-complex animation in Fusion...

I just want to make some heavy objects to be present for calculations only when they're on screen.

For instance, I have a few 3D objects laying on a plane and a camera going from one to the other. When an object is out of frame, I'd like to "disconnect" it in some way to improve render times, and reconnect it a few frames before he comes to play.

If found I can't just simply triman object in the timeline. When I do that I get an error because any 3Dmerge node downstream will fail without the input of the trimmed branch.

Another thing I've found is that you can trim a 3Dmerge in the timeline but doing so will not "disconnect" all the geometry of thet node, the scene.input.1 keeps passing through. I behaves as a 2Dmerge.

So...

What's the normal and easy way to do what I want? There's must be one.

Thnx!

then, no way to do that?

I'm used to animate MAX and good'old Combustion. With both you have several methods to tell the renderer when an object is no longer needed.

Maybe Fusion renderer is so well optimized that it's already ignoring out of camera objects but probably not. To be reliable It should consider projected shadows, or reflections in that are on screen...

If the AABB is outside the frustum of the camera and spotlights, it won't render at all. I'm not sure how complex the animation is, but normally it isn't enough to matter.

Today I'm with the same problem.

This time I have dozens of image planes lined up horizontally over a texture background, and a camera flying around. Each plane is feeded with a shot of UHD. They are initially hidden with a mask, and at some point in the timeline (when the camera is over there), they became visible for a few seconds and then fade out.

Each plane is 4" but the full comp is almost three minutes. And it seems FUsion is handling all videos even when there are only two or three visible. To syncro videos I'm playing with the Hold in and Hold out. But the layer is always present in calculations, with assigned UHD frame.

An animatable "Visible to camera" object parameter would be a solution.

An animatable "Visible to camera" object parameter would be a solution.

Would be or is?