camera track to object track

[opus2761]

 

Hi, 

Something that I couldn't figure out how to do in houdini... If I have a still object and an animated camera, how can i convert it to an animated object with a still camera and still get the same result? 

Any help is greatly appreciated!

 

[evanrudefx]

Hey,

I don't know if it is possible to do that 100% perfect. Here is a scene that works pretty well. The first and last frame are exactly the same, but its a bit off in the middle. This is the closest I could find.

extract.hip

[anim]

just use Fetch Object using Invert Fetched Transform to get your camera's transform and convert, then parent your scene to that 

(so ideally you copy your camera to fetch transform from so that you can parent the whole scene with original cam under the fetch obj)

invert_camera_transform.hip

Edited December 14, 2019 by anim

[julian johnson]

Whilst Tomas's is as elegant/definitive as it gets if you were inclined to use either vex or chops (and, realistically, you probably never would!) here's a scene with rough workings for a vex version and a chops version...

vex_and_chops_camtoobjtrack.hipnc

[opus2761]

thank you all so much for taking time to solve this for me!! I got more than one solutions from you guys and they helped me clarify some confusions I've been having with matrices. Very grateful!!!