Time remapping bug with lights and imported null from Cinema4D (aec)

[0ather]

Hello!

I'm working on a video clip project where I did 3D renders of a moving car in Cinema4D. I also exported a AEC file to get the front and rear lights position of the car. I imported everything in After Effects.

My compositing hierarchy is as below:

--- Pre-Comp with 3D render

-- Pre-Comp with car lights position and flares

- Main Comp with the car Pre-Comp (Collapse Transformation to get the shadows; hidden here to get a better view) and Background

This way I can adjust the car position, duplicate, good enough!

For this scene I needed to speed up the car mouvement so I did a time remapping on the car Pre-Comp. I don't know if my compositing workflow is the best but now, as you can see in this video I made (here: Dropbox - AFX_TimeRemap-BUG.mp4 ) I have glitches and issues with my lights position. In this screencast the first part is the second Pre-Comp (with car lights position and flares), second part is the main Comp without time remapping and the third part is with time remapping.

If you reached the end of my topic well done! My question is: are these glitches and bugs part of my compositing workflow or is it a AE bug? ^^

Thanks guys

Florian

[Dave_LaRonde]

0ather  wrote

....are these glitches and bugs part of my compositing workflow or is it a AE bug? ^^

It's more of the improper choice of applications.  You ought to be doing this in C4D and not AE.

[Rick Gerard]

Those glitches look like cache problems to me. Purge everything and try rendering again.

If all else fails nest your original comp in a new one and turn collapse transformations off before applying time remapping. This is almost always a good idea. The only thing I know that won't allow this is Particular from Trapcode and a few other particle and time effects. You just have to render those layers and replace them before you apply Time Remapping.

[Mylenium]

Nothing to do with cache glitches. Those are issues in Optical Flares due to its OpenGL renderer and the position of externally referenced elements not updating fast enough. You have to use the software render mode and turn GPU usage off or pre-render the sequence.

Mylenium

[Rick Gerard]

Great catch Mylenium. The rendering speed of the different effects did not even cross my mind.

[0ather]

Hello guys!

Wow thanks very much for your replies! I'm gonna try on Monday your solution and I'll let you know.

I'd never thought it was caused by GPU/OpenGL calculations so thanks for pointing out this issue!

Cheers and have a good weekend,

Florian

[Szalam]

Did the recommended solution work?

[0ather]

Hey guys!

Sorry I just find the time to try out.

- "Use GPU" option is unchecked in optical flares plugin.

- Comps 3D Renderer is Classic 3D.

- Video rendering mode is Mercury Software.

- Hardware Accelerate Composition, Layer and Footage Panels is unchecked from the preferences.

Unless I missed something in your recommandations Mylenium, the only solution is to prerender.