Odd behavior with grade layer in a 3D environnent.

SpaceEye Posts: 37 Just Starting Out
edited January 2019 in HitFilm


I'm experiencing an odd behavior with a grade layer using Hitfilm Pro 11 on Windows.

I create 3 layers from a transparent PNG, in a 3D environment  (with a camera, each layer being in 3D too).

Each layer is on a different Z coordinate.

All of them are attached to a point for the purpose of the demo (to easily manipulate them in 3D).


First test:

00:01 front most layer is untouched, 2nd and 3rd layers have effects applied on them. When I rotate around Y axis, everything is fine, my effects are perfectly applied on layer 2 & 3. => GOOD!


Second test:
00:21 I tried to optimize it by using a grade layer applied on layer 2 & 3. Front most layer is untouched, 2nd and 3rd layers have NO effects applied on them, previously applied effects are on the grade layer now.
When I rotate around Y axis, I have an odd behavior with my front most layer beying always visible despite the fact it is behind layer 2 & 3 at some moment of the rotation.
Is the behavior normal with the grade layer, and do I miss something to make it work with the grade layer like in the first test?

Here is a video of my tests: https://youtu.be/uEEMT0NpnYg

And the project file for those interested :-)



  • Triem23
    Triem23 Posts: 20,397 Power User

    Hitfilm's 3D space is actually 3D spaces - plural. A fully 2D photo/video/grade layer separates the 3D spaces from each other. This is normal and expected Hitfilm behavior. 

    Grade Layers especially. What a Grade Layer does is force a render of all layers below it (in 2D) then pass this "flattened" 2D image to the effects stack. In your particular case your top layer is in a 3D space separated from your bottom two layers by the grade layer - which is a 2D render of the 3D layers below it. 

  • tddavis
    tddavis Posts: 5,254 Expert
    edited January 2019

    @Triem23 I just downloaded the project file with the intention of trying to create composites shot of the layers then apply a grade above all in another comp.  Would that have made any difference? Like locked the layers 2 and 3 so the grade didn't strip the 3d-ness?

  • SpaceEye
    SpaceEye Posts: 37 Just Starting Out

    Thanks @Triem23 your explanations make perfectly sense. So 3D spaces are much more complex to handle than I imagined.

    @tddavis, I also tried to create a composite shot with the sublayers, but it does remove the 3D depth in the process, so no luck also. 

  • Triem23
    Triem23 Posts: 20,397 Power User

    @tddavis only if the grade layer is over all 3D layers. An embedded comp is basically a rendered 2D layer (unless it's a 3D unrolled comp). You've hit a different issue with this before in 3D spaces with lights separated from models by a grade.

    @SpaceEye not too much more. Just pay attention to where grades go. Being able to separate 3D space into batches often is an advantage. There are creative options from being able to  say, add in a light that hits object A and not object B. The grade layer being a 2D render of everything below it is often used in Hitfilm compositing under the creative name "The Grade Layer Trick" where layers can be combined and edited then slapped under a grade layer and the grade layer itself becomes the source for another effect like a set matte or light wrap. Sometimes a grade layer prevents having to use embedded comps. 

    VFX is tricky, but Hitfilm has pretty consistent internal logic. Like with any software or skill time and practice will help you learn and, one day you'll have the "Eureka" moment where suddenly everything makes sense. 

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