Random expression errors that solve themselves and not rendering in AME

Got it, keep it simple! 🙂

All of the errors disappeared after ensuring I did not get out of bounds. I still see the value in just keeping it simple though. The last problem of rendering this in a good way was solved by simply dragging the CSV-files into the layer panel. I did not change any code to reference them in any other way than I already did.

But this seemed to add them to the project so that I could use dynamic link in Premiere. The project file went from 1 Mb to 114 Mb, so something happened. Then I can render in AME and get just one render of a good enough quality and I don't have to render two times!

Thanks for clearing that up!

Is it so that expressions are sandboxed per expression window, layer or composition in a way? From where to where are they linearly evaluated? Where does a variable stop being "global"?

Thank you!

I’ll try to break it down and explain as best I can. This happens on two different systems. One powerful workstation and a weaker laptop. Both run Windows 10 and AE-version 18.1.0 (Build 38). I am using the English version and all my data have English characters.

The expressions are bringing in data from two different CSV-files. I am trying to build a workflow where I can just swap the CSV-files and the data will change. Therefore, I am referring to them as footage rather than dropping them on the timeline. If dropping them on the timeline is better, and I can still just swap the files out, please do tell.

The CSV-files are numerical and textual data where each row corresponds to 1 elapsed second. That way I can floor time and use that to bring out the correct data. I have set the composition length to be the same length in seconds as the CSV to avoid any problems there.

Here are my expressions:

On a source text layer to display a timer:

let sek = Math.floor(time);
footage("workout.csv").dataValue([5, sek]);

On a sound layer to play a 6 second sound clip when the timer hits 5:

if (Math.floor(time) >= 1) {
    let sek = Math.floor(time)-1;
    let currentCountDownTime = footage("workout.csv").dataValue([5, sek]);  
            if (currentCountDownTime <=6) {
                        (time%1)+6-currentCountDownTime;
            } else {
                        0;
            }
} else {
            //This else block seemed to fix one of the returning errors
            0;
}

This is on a shape layer with trim paths to animate a stroke:

let sek = Math.floor(time);
let st = footage("workout.csv").dataValue([8,sek]);
let tot = footage("workout.csv").dataValue([8,sek]) + footage("workout.csv").dataValue([9,sek]);

linear(time, tot, st, 100, 0);

And then I just have a lot of these expressions on text layers to display different things:

let sek = Math.floor(time);

"SPEED: " + footage("workout.csv").dataValue([6, sek]).toUpperCase();

Problem 1: Wrong data shown (solved)

Everything seemed to work fine when previewing and rendering in After Effects, except one thing. That is, I get all the data I expect, but for one frame in one layer. This expression is used:

let sek = Math.floor(time);
footage("workout.csv").dataValue([5, sek]);

I checked that “sek” was 0 on both working frames and the offending frame. I also checked that hardcoding index 0 gave the correct data on the offending frame. But the combination gave the wrong data, specifically 14 instead of 45. The default on the text layer was 60.

I have tried clearing all cache and turning everything on and off again. Nothing worked. And then suddenly after not having worked on it for a few hours it works again. I am just listing the error here for reference.

Problem 2: Random expression errors

I still seem to be getting some errors like this:

This one can happen for a lot of the layers with expressions. Note that "awesomeSek" is just from me trying different variable names because I thought I might have some collisions. This one can happen at the very start as well as the very middle of the timeline. I don't know why, because the length of the composition is the same as the CSV file. I don't quite understand it either. Is it saying that it tries to get index 3601, but that there are only 3600 present?

This one is fun, I think! It expects a semicolon, but the semicolon is already present. The expression also works perfectly fine.

This is the last one I have managed to get a screenshot of. Something is missing here, apparently, but not on the next line where the expression is basically exactly the same?

I don’t quite understand all these errors, and they appear and disappear randomly. I find it hard to pinpoint a cause. They can be there for one layer, and if I hop a few frames forward they disappear. Later the same error, or a different one, appear for a different layer, or the same.

Problem 3: No expressions are rendering in AME

When I do test renders losslessly, or in fact using any codec, straight from After Effects, everything shows up. When I try to do it from AME, nothing seems to work. The layers are stuck on their default settings (expressions not executing) or layers are just gone. Sometimes AME just hangs forever. It can hang while trying to connect to dynamic link with a progress bar at the bottom, but it can also hang without any progress bar and just nothing happening. I am trying to render using h.264.

Here is an example of expected result and actual render the few times I get it to work.

It can also be that the layer is visible, but static on the default value because the expressions are not evaluating.

Problem 4: How to render this in an efficient way?

Lastly, I am wondering what is the best way to render such a thing? It’s just an overlay that changes data every second, but the files get huge if the quality is to be good. Is it possible to render in a way that only each second gets rendered with "new data"? I am thinking almost like vector data that just changes. I am going to import this into Premiere Pro and render it on top of another video. I want to avoid double compression in addition to huge file sizes.

Thank you very much for your time in this matter!