I assume the elements are in 3D space? If so, then their position in the timeline generally doesn't matter. It's their position in 3d space that matters. if two images are on the same position in Z space, that will cause problems. Simple move whatever element you want forward by 1 pixel to fix that issue.
Hope this helps,
Thank you, Digital Spatula, but I have already done that as well. I even tried seperating them more than 1 pixel in height.
Any other tip?
Clear your cache - Edit>Purge>All Memory & Disk Cache
See if this helps by committing to a Preview by setting your WorkArea to encompass a duration slightly longer than the problem frames. If purging cache and memory doesn't help then I would take a look at how the layers and lights are set up from multiple views - just to see if one or more lights has its Light Settings and/or position in such a manner as to create this issue.
If purging the cache does not fix the problem and you can clearly see the problem in the composition panel then go to the first frame where the layer goes black, select all layers and press the U key twice to reveal all modified properties of the layers and start turning things off or moving things. If you start by soloing the layer giving you problems and start turning the other layers on you will probably find the problem in a couple of minutes. When you find the problem start turning things off, moving things, or changing layer order until the problem goes away.
Your screenshot does not help us find the problem because we can't see the modified properties of the layers involved so everything is just a guess.
Thank you Rick and Roland!
I emptied my disk cache and went to the first black fram with full resolution on - it´s still black.
I pressed U. I have no keyframes set at that frame on any layer.
"If purging cache and memory doesn't help then I would take a look at how the layers and lights are set up from multiple views"
I don´t really know what to look for. I have two lights. I moved one but it didn´t change anything. Start moving random layers around sounds almost like rebuilding the scence...
This is scary. It sounds to me like this is something that just happens sometimes and no obvious solution is at hand. This would really be a stress factor for me personally. Work in 3D space takes alot of work and render time for me, and the least "help" along the way that I would expect is for After Effects to work logically. It does with the rest of the 12 photos set up the same way as the black one in my comp.
I really appreciate the help here, thanks again. If there´s even the slightest tip left that you can give I´ll try it right away Otherwise I guess I´ll have to live with flashing black frames in my upcoming projects. With luck, they will be few.
I've taken a closer look at the two images you've provided and I believe a better description of your problem is "two images/photos are superimposed incorrectly". Specifically, your problem frames occur when a layer that is supposed to be below another, suddenly appears at the top.
So, I would dive in really close into the Timeline, to ensure that there are no KF(s) that were inadvertently added to create this issue. Check for both Position and Rotation/Orientation properties.
If the problem persists, you may want to post a link to the AEP so one or more of us here can take a closer look.
I seriously doubt it's an AE issue.
You need to press the U key twice to reveal all modified properties of the layer then solo the one that is turning black. Pressing U only reveals keyframes. They are pretty useless for diagnosing this kind of problem. If it turns black when soloed then there is something other than layer order and position that is causing the problem. If it does not turn black then start turning on layers until you find what is causing the problem then make adjustments to that layer. If you can't figure it out we need a screenshot that shows all modified properties of the layer giving you problems and any other layer that may contributing to the problem.
Thank you both Rick and Roland! I´m gonna try everything you wrote, of course.
I just need to understand one thing first - when saying two layers should not have the same height, does that include photos that are totally seperated by width as well? That don´t cross over at all? Let´s say one photo is in the right corner and the other in the left?
Meaning, could this black frame on the photo be because not of the photo on top, but because of a photo somewhere else in the comp, perhaps not even in view at the time of the black frame?
In turn, would that mean that if I have let´s say 12 photos, only one could be placed at 0,0 height, only one at 0,1 height, only one at 0,2 height, etc, etc?
Sorry, english is not my first language. Some things are hard for me to describe.
Rick and Roland! I might have managed to fix the problem thanks to you guys. Instead of trying extremly small corrections in height like 0,1, I tried moving the ID-photo a full 2,0 instead. The black frame is gone on that frame and the visual difference is basically nothing.
I will have to render the comp to see if the problem is fully fixed That only takes 15 hours.
Rick, you once told me not to work a 2 minute film in one comp to save time. You were right. Thanks.
Also take note that Motion Blur can create overlapping issues in 3D space when two objects are very close in Z space. If the problem layer has Motion Blur enabled. switch it off temporarily to diagnose the issue. If it is the cause, you know you need to either remove Motion Blur, or seperate the layers in Z space enough to remove the problem,
Thanks, Andrew, I have no motion blur. Would have like to try but I think the render time would be 3 days
A 0.1 Position difference in z-space may be sufficient if your images are not rotated/orientated. When rotated/oriented, a larger differential in z-space position may be warranted.
Good that you sorted the issue out.
Roland, thanks, I´ll keep that in mind although it makes no sense to me. If an object is rotated on the diagonal I would´ve though the difference in height would be unaffected.
LARV, if this ends up not being the solution, you can also brute-force the layers to be separated in 3d space by placing a 2d adjustment layer (it can be empty) between them on the timeline. If you don't otherwise need 3d interactions, this can be a workaround when changing Z position either isn't feasible or doesn't seem to be fixing things.
Roland is pointing out that small Z-space differences may not be enough to prevent intersection if one layer is rotated in a way that would cause it to intersect another.
LARV, if a 3D layer is rotated in either of the X and/or Y axes, then the z-position differential may have to be increased to create sufficient separation. I've seen issues crop up, very infrequent but it has happened; similar to your due to the cause I've mentioned.
In a nutshell, just ensure there is sufficient separation between the layers' z-position; as you now know.
Great! So simply inserting an adjustment layer between the two might fix the problem? I haven´t set the comp to render yet so I´ll add that as well before rendering.
"In a nutshell, just ensure there is sufficient separation between the layers' z-position; as you now know."
Thanks, Roland, I think I have now that I heightened the top photo from something like 0,2 to 2,0. At least the problem went away on the frame with the problem. I will render it out soon and see if everything is ok
3D interactions are defined as (1) intersections - where 3D layers can intersect each other (2) shadows - where 3D layers cast shadows onto other layers and (3) light transmission - where a 3D layer casts its colors onto other 3D layers.
So, be cognizant of these issues when inserting a 2D layer in between 3D layers since it is quite often the case that you do want 3D shadows and intersections. BTW, an Adjustment Layer or even a 1x1 pixel solid; placed outside of the active Comp Area and placed between 3D layers, will break 3D intersections.
"BTW, an Adjustment Layer or even a 1x1 pixel solid; placed outside of the active Comp Area and placed between 3D layers, will break 3D intersections."
OK, but this must ONLY include adjustment layers and solids then, right? Since I have photos "laying on top" of other photos in my current comp that have multiple other layers in between them in the timeline, and they all look OK in the rendered movie.
I have found that if you are careful when you line up the 3D layers on the stage and if you have at least 1-pixel separation in their position and the layers are parallel you will not end up with any unexpected interactions. On occasion, you need to break the rendering order so inserting an empty 2D adjustment layer or a small or even almost transparent solid will do the trick.
If you think of the stage you are setting as a real place and you are throwing photographs on a tabletop they will not all be at the same level as the table. They will be offset by the thickness of the paper. In AE, the paper is 1 pixel thick so that has to be the minimum offset.
Any 2D layer placed in the Timeline, between 3D layers, will break 3D interactions.
More details are available here - Use 3D layers in After Effects
I'm not certain that you should be too keen/concerned with disabling 3D interactions. It's not exactly a good thing. The most often use-case where you do not want 3D interactions is if you do not want 3D Layers to intersect - when flat imagery intersects, it often doesn't look good even though such flat intersections may be what you want on certain occasions.
For your specific issue, breaking the 3D interaction may not have helped - I can't be certain but if you want to dive deeper then it's an easy test on your end since you now know how to break 3D interactions. A more elegant solution would be what you did and that is to increase the z-position differential between the two affected layers.
This is impossible... I just rendered it out now that I had heightened the top photo. Instead of flashing two times it flashed constantly, about 200 times. I now know I can´t trial and error this by just going to a single frame...
I have too many layers to just randomly lower or heighten. I can´t go thru them all. 60 hours of work wasted. F****g s***t, this reminds me of working in the nightmare Adobe Edge Animate...
I also relaized that heightening the top photo makes no difference. The Photo is still colliding with the side of the book.
And many layers are on the 0 px height, and they look fine. I get contradictory information...
Thanks for all the help, though.
And fix the issue, Adobe.
It looks like a complex project. Sometimes that means you run into complex problems, and we can only do so much to diagnose on a message board. There are probably hundreds of different combinations of things that could ultimately be in play here. This could be due to an actual problem with the way After Effects is handling something that SHOULD work, or it's possible you just built it wrong. It could also be due to your video card (are the drivers up to date?) or any number of other things actually unrelated to After Effects itself.
If you can precomp this thing, or otherwise isolate it, that can be a good way to troubleshoot and/or find an alternate solution. Try using a matte so the offending layer doesn't "exist" there. Solo the piece and pre-render it. There are a ton of workarounds that can sometimes end up being easier/faster than pulling your hair out trying to "fix" it.
Thank you, Kyle, I was just so frustrated when I saw the 13 hour finished render when I got home from work. It´s obvious I´ve built the scene wrong when it comes to placing the layers correct. It´s too late to fix every layer. I think I´ll continue to try and just randomly tweek stuff, moving layers around, etc, etc until it works. I´ve no other option since I can´t find a way to zoom in on the problem/problems.
Perhaps I can precomp the two photos into one precomp. I´ll try that tomorrow. But usually precomping adds changes that I almost never want. I bet for example that precomping my two photos will mess with the lightning and shadow.
If I only knew if it´s the top photo or the photo on the bottom that´s causing the problem. That might save me days of just tweeking randomly. But I don´t know which one is causing it.
Thanks anyway, Kyle.
Can you render that photo/photos solo'd and just lay it over the top?
Sorry to hear of your continuing issues. I'm in agreement with Kyle, that you render everything except the layer which is on top of the other. Once this render is done you will find out if the issue is indeed due to the layer at the top OR something else. And if the render goes well, you then render the top layer on its own; with an Alpha Channel. Then use PPro to combine both renders.
1 person found this helpful
I don't recall you ever saying how long the comp was. Most of my comps are single shots and under 7 seconds. If you have more than one shot in your comp I would break up the comp into smaller pieces, render each piece separately and put them together in Premiere Pro or your NLE of choice.
When you have projects that are going to take a long time to render or you suspect that there may be rendering issues you should be rendering to an image sequence, not a movie. That way if something goes wrong at frame 143 you can pick up where you left off after you fix the problem. In your case, if you have 40 frames where the layer turns black you can fix those 40 frames and then render just the bad frames again. It will save you a ton of time.
Then just import the image sequence back into AE or Premiere Pro, verify the frame rate, add your audio track and render again. You should see render times from an image sequence 8 or 10 frames per second on a modest system.
Good luck with the project.