Glitch with a 3D model render - Sample footage

laconstantedeplanck
laconstantedeplanck Posts: 73 Enthusiast

Hi there :)

Here's a sample video. If you look to the farthest part of the ceiling, you'll notice some small glitches as the camera moves due to the casted shadows of the ceiling itself. I've tried with different lights and positions, and also tried different framerates, but I always end up with a lighting glitch of some kind.

I've also noted that around 0:11-0:12, some shadows appear on the right hand side on the wall. It's like the camera itself is casting shadows, but I'm unsure on how to avoid that.

In this sample, the camera movement is keyframed manually, but it will be replaced by a 3D Mocha-solved camera to put some greenscreened actors on the hallway. I've already tried with the more natural look of the Mocha-solved camera movement but still the same glitch appears.

It seems I'm missing some cast shadows/casts reflections setting under the materials tab...

Have you seen it before?


Comments

  • FilmSensei
    FilmSensei Posts: 3,108 Expert

    I've had the exact same problem with that corridor. Of course, the Youtube compression makes it more difficult to see the issue, but I know what you are talking about. A couple of questions...

    How many lights are in the scene and where are they placed? What is the color and intensity of those lights? Do you have an Ambient Light in the shot to help fill in some of the shadows? That would go a long way toward removing those artifacts.

    What settings are your rendering at? Take a look at this video that I very quickly put together from a project that I am working on. See the difference in quality of the shininess on the model just from rendering at a higher rate? Again, you may have more difficulty seeing it due to the Youtube compression, but i am sure you'll get the idea.


  • laconstantedeplanck
    laconstantedeplanck Posts: 73 Enthusiast

    Thanks @FilmSensei for your fast and detailed answer :)

    There are three lights in the scene, all of them being white point lights with an intensity of 100%. Two of them are placed just next to the white vertical illumination present on both walls. The third one is placed way down on the Z-axis so the floor can be lit. I'm testing now with an additional ambient light, but it won't have any effect on the model. May it be related to being in the 3D unrolled mode?

    I tried changing the project settings and exporting both [email protected] and [email protected] files. The 60fps is a bit better but still have the same issue. I'm going to add a few more lights with less intensity so the shadows are not that heavy and I'll let you know. I'll also try to export in Cineform so maybe being an uncompressed format might help. Again, thanks for your advice!

    P.S. Your 2021 footage looks great! Your 32bit footage seems smoother than the 8bit, so I'll try that also.



  • Triem23
    Triem23 Posts: 20,061 Ambassador

    This is the Andrew Kramer corridor model?

    A couple more thoughts.

    In the Project Settings menu, Rendering tab consider turning up the shadow map resolution. Some of the flicker looks a bit like pixelating shadows. Higher res is better quality shadows, but longer render times.

    Hitfilm 16.0 has a render bug with 16-bit and 32-bit LINEAR on some GPUs. You might want to avoid those two color depths for the moment. If you go to 16/32 bit LINEAR and suddenly it looks like your lights moved, you've hit the bug. Hopefully it gets patched soon, cuz the Linear modes usually have the most realistic lighting response.

  • FilmSensei
    FilmSensei Posts: 3,108 Expert

    @laconstantedeplanck

    Here is a render using the corridor model that I did way back in November, 2017 in HitFilm Version 5...

    I rebuilt the corridor this morning and ran it again. I set the Project Settings to 32 Bit Float and 32X MSAA with a 4096 Shadow Map size. It took 2:15 hours to render this 15 seconds. Here is the result...

    The Youtube comporess may make it more difficult to see, but I feel there is definitely an improvement over the previous video. What do you think?

    PS: I did a few things differently. One is that I didn't add a reflection plane. Another is that did add a "Lights Layer" using the Emission Map. By adding a few glows on that layer, I think it really it really sells the lighting of the scene. Feel free to ask more about those if you need to.

  • laconstantedeplanck
    laconstantedeplanck Posts: 73 Enthusiast

    Sorry for taking so long to reply, I've been busy during Christmas and New Year.

    Happy New Year to both of you!!

    @Triem23 I'm unsure whose corridor is this. I downloaded it as a pack named "VC_StarPack" which included not only the corridor but some other 3D models like lightsabers, droids and spaceships. If I recall properly, the download link was freely provided in the description box of one of Fxhome's or VideoCopilot's videos. I can share it to you if you're interested. I'm still using Hitfilm 15 at the moment as I usually don't like to upgrade while working on a project, I'm planning to upgrade it this week. Thank you so much for pointing out the shadow px resolution, it made a substantial difference (see the link below).

    @FilmSensei Thank you SO MUCH for rendering the whole thing and pointing out the rendering specs. I was able to render it under 16 bit (I'm using Express) alongside MSAA and 4096 shadow pixel size and, despite the rendering process took quite long, the results are way better:





    Thank you so much to both of you for pointing those specs out :) It worked way better.

  • FilmSensei
    FilmSensei Posts: 3,108 Expert

    @laconstantedeplanck Wonderful!

    Yes, the corridor is from Andrew Kramer's Video Copilot Star Wars Pack...

    It contains several other very nice models including an X-Wing, a Tie Fighter, R2D2, etc....