Why does multiple layers make the export look glowy/blurry?

Sulit100
Sulit100 Posts: 6 Just Starting Out*

Hello,

I use Hitfilm to make 2d animation stuff, but I have found that when many layers are on screen at once (in a comp shot), the export has a kind of glow to the layers, and the more layers, the more glow. The lowest layers have the most glow. This test picture only has 15 layers (including background), but I have tried with many more layers and the video just becomes unwatchable, since it at just looks like a big blurry mess.

There are no effects on this test I made, and they don't seem to make a difference.

This is how it should look (what it looks like in the editor)

And this is it when exported:


I do not believe it has anything to do with the export settings, as the blury/glowy thing, comes even in just a picture export. But here are my export settings anyways:

I have tried other exporting settings, but it doesn't affect the glow/blur.


Is there any way of fixing this?

Best Answer

  • Sulit100
    Sulit100 Posts: 6 Just Starting Out*
    Accepted Answer

    I have found the problem!

    Under project settings (File>Project settings) and then under the "Rendering" tab, the antialiasing mode was set to 16x MSAA.

    Setting it to 8xQ CSAA, 8x MSAA or 4x MSAA fixes the problem!

Answers

  • TerryS
    TerryS Posts: 127 Enthusiast

    If you export a frame, does the PNG exported glow also?

  • Sulit100
    Sulit100 Posts: 6 Just Starting Out*

    Yes it does. In fact the picture posted up there is just a png export.

  • TerryS
    TerryS Posts: 127 Enthusiast

    Perhaps someone else with have an idea?

    I threw together a comp with a 16 layered images and a text layer on the bottom. The text remained sharp using your export settings.

    I was using 4K settings, I see you are using 2K.

    I even reduced export to 1080p YouTube quality. As shown in the image below.

    It seems there may be a minor blur on each layer of your project, compounded through layering. Why that is???

  • Sulit100
    Sulit100 Posts: 6 Just Starting Out*

    I am using Hitfilm express. Perhaps it's a limitation with the free software that I'm not aware of?

  • tddavis
    tddavis Posts: 5,096 Moderator
    edited December 2020

    @Sulit100 I am so glad that you found the source of your problem, and especially happy that you came back to outline the solution for others. That may help others...TBH, my old eyes could not begin to see the difference in your images so I didn't even try to weigh in. But I will say there are no limitations on Express that I know of other than watermark on add-ons that need purchasing (and when the program doesn't get successfully activated) and the lack of PRO only features. No time or quality constraints at all.

  • TerryS
    TerryS Posts: 127 Enthusiast

    Thanks @Sulit100 ,

    I can replicate your results/error/Render Style? ............. Check it out.

    Now, why the heck does 16X MSAA screw up layers instead of improve them ? More multisample anti-aliasing.........Better results? But No?

  • NormanPCN
    NormanPCN Posts: 4,081 Enthusiast
    edited December 2020

    Now, why the heck does 16X MSAA screw up layers instead of improve them ?

    16x and 32x MSAA settings soften because that is what they are intended to do. Why? Who is to say. They may not be pure MSAA but a combo of up to 8x hardware MSAA and some driver softening.

    16 and 32x MSAA are things that should never be used. Nvidia and AMD do not make this available in their control panels. That should be telling enough. IMO FxHome should not offer those MSAA settings. I've never heard of anyone who likes the results.

    --

    The OP screenshot showing the viewer good is because AA is not being applied in the viewer. The viewer setting is shown as "full".

  • TerryS
    TerryS Posts: 127 Enthusiast
    edited December 2020

    @NormanPCN Yeah, but it screws up the layers worse, based on layer order. Thats whats doesn't add up to me.

    Shouldn't all layers blur equally. Which is not what is occurring, Why? The lowest layer is blurriest, and the uppermost are much sharper.

  • TerryS
    TerryS Posts: 127 Enthusiast

    @NormanPCN ,

    I can understand why Nvidia and AMD wouldn't make 16 and 32 MSAA available to gamers. It would most likely plummet in game FPS with all that going on.

    However, for video rendering.It can have a beneficial effect.

    I still can't make heads or tails of why the highest layer in the stack is relatively sharp, and the lower you go in the stacking order, the blurry they become. Which is why this [post was created. Thoughts?

  • NormanPCN
    NormanPCN Posts: 4,081 Enthusiast
    edited December 2020

    However, for video rendering.It can have a beneficial effect.

    You are free to make any assumption you like. The driver/hardware does what it does.

    The 16x and 32x modes as FxHome listes them cause overall blurring (visible). Not just on geometry edges.

    I still can't make heads or tails of why the highest layer in the stack is relatively sharp, and the lower you go in the stacking order, the blurry they become

    It is probably because the AA step is applied at each level/layer of the composite. Since the 16/32x modes as listed in Hitfilm cause overall texture blurring then the small blur accumulates. The first/bottom layer gets blurred the most.

    --

    First I can only speak to Nvidia. It is what I have and what I can test. I have a GTX 1080. Hitfilm does lists 16x MSAA and 32x MSAA for this GPU.

    I believe FxHome are incorrect in their listing here. 8x MSAA is probably incorrectly listed. It is probably the "plain" 8x AA mode of Nvidia which is more like 4x MSAA with an extra 4 coverage samples. 8xQ in Nvidia speak is an actual true 8x MSAA. Not CSAA. Nvidia does not have 16x and 32x MSAA. Period.

    Here is a somewhat technical listing from Nvidia Inspector of the reported AA modes on my GPU. Far more than Hitfilm lists. The text in brackets is the description of the mode by the inspector.

    I don't know exactly what algorithm is used by the Hitfilm listed 16x MSAA and 32x MSAA modes. I just know they visibly blur the texture overall. Not just geometry edge areas.

    ---

    Back to my statement "It is probably because the AA step is applied at each level/layer of the composite".

    A couple of screenshots.

    All layers are 2D.


    The pumpkin layers are 3D.


    AA mode is set to 32x. pumpkin(1) is the top left image. pumpkin10 is the lower right. Also note that there is no geometry overlap here.

    Notice that the 2D layer version the texture blur gets progressively stronger. Notice the 3D version they all appear the same.

    This comes down the to render order of Hitfilm. It is defined in the user guide.

    Likely the 2D order is the bottom layer gets full/complete/finished OpenGL rasterization. Then this result is included in the next GL layer render. The new layer effectively rendered on top of the previous. ...and so on. Thus the first/bottom gets more blur.

    Now the 3D render sequence all the consecutive 3D layers without a 2D layer in between are rendered in a single GL raster phase. This is the Hitfilm unified 3D space. Nothing grandiose. Just letting OpenGL do the all work. So AA is applied once for all 10 pumpkins. One GL render phase. Now If I put an empty grade layer in between each 3D layer the result should be the same as the 2D comp. The 3D layers are no longer consecutive.

    Final note. AA only applies to 3D models and text layers (text panel) (text effects are unique). Things with geometry edges to be smoothed. This is speculation but those pumpkin PNG planes are "3D models". They are just simple flat planes with a texture applied. When perpendicular to the camera Z axis, then AA is never needed. If those planes become Hitfilm 3D planes and I rotate the plane then the edges can get jagged and AA can clean that up. Hitfilm is a 3D compositor after all. Remember that 2D can just be a restricted/constrained case of 3D. The Z-axis being fixed to some setting relative to the "camera". AA has no meaning to the myriad of pixel effects Hitfilm has. For those who have been around a long time you can remember when Quad Warp generated jagged edges. Until FxHome implemented an AA feature for that effect.

  • TerryS
    TerryS Posts: 127 Enthusiast

    Well, thats certainly a lot to digest. Thanks for the feedback.

    However, for video rendering.It can have a beneficial effect............

    I was thinking of this post, where 32 MSAA seemed to be the ticket to eliminating lighting artifacts for @FilmSensei

    https://community.fxhome.com/discussion/55351/glitch-with-a-3d-model-render-sample-footage#latest

    It seems the corridor had created rendering problems for quite some time. Maybe theres a simpler solution?