QLab Gloom effect issue

matcreyn

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Hey, folks, I wonder if any of you have an idea on resolving a particular QLab 4 issue I’m having.
The look I’m going for is to make the lungs png I have inhale and exhale in a continuous loop. I’ve built the loop group (say that five times fast). The closest video effect I could find in QLab was Gloom at full intensity (1) vacillating from radii of 0 to 17ish. It was working fine but after first tech it’s now stuttering so that on every inhale (radius 0) the image steps down twice about 10 pixels, and on every exhale the image steps up twice about 10 pixels. I checked all the properties to make sure everything was identical and even tried to compensate by adding a translation but to no avail. How can I get this image to stop stuttering?
Thanks,
Matt
 

Colin

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I havent used that effect, but if the same effect configuration was working before and is stuttering now, that sounds a lot like your computer is having trouble keeping up (common once you start adding effects within QLab rather than prior). What are you running QLab on, and outputting to what?
 

ruinexplorer

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Just to be clear, nothing has changed since building the file, right? You are on the same computer and no other files have been changed/added. I only ask because, I have run into this in Isadora where if I start building where I have the greatest challenge, then after I accomplish that I build additional cues, the initial work no longer works correctly. One of the things that can catch you is if you are using different file types in different cues (such as .mp4 in one scene and then photo jpeg in another) that the media program is slowing down as it accesses other required components to display the various formats. This could also happen if you are using this .png and you are also using .bmp for other bits in this show file.

Is it possible to render the file in After Effects and then just play back a loop instead of using an effect in Qlab?
 
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matcreyn

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I havent used that effect, but if the same effect configuration was working before and is stuttering now, that sounds a lot like your computer is having trouble keeping up (common once you start adding effects within QLab rather than prior). What are you running QLab on, and outputting to what?
Mac Pro 2018, 2GHz RAM, about 100 GB open storage space, only running QLab when in show mode. Even when it’s the only file and effect running, it stutters in time with the effect. The greater the radius, the greater the stutter. The png itself is a long vertical file and the lungs are at the bottom, so I wonder if the effect is pinching the whole image towards its center, which is high above the visible lungs.
 

matcreyn

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Just to be clear, nothing has changed since building the file, right? You are on the same computer and no other files have been changed/added. I only ask because, I have run into this in Isadora where if I start building where I have the greatest challenge, then after I accomplish that I build additional cues, the initial work no longer works correctly. One of the things that can catch you is if you are using different file types in different cues (such as .mp4 in one scene and then photo jpeg in another) that the media program is slowing down as it accesses other required components to display the various formats. This could also happen if you are using this .png and you are also using .bmp for other bits in this show file.

Is it possible to render the file in After Effects and then just play back a loop instead of using an effect in Qlab?
Yes, there are multiple file types (mp3s, pngs, mp4s) but even when running only that cue it happens. Yeah, I could build it in After Effects, but I’d prefer to have the ability to tweak the timing on the fly.
 

ruinexplorer

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I completely understand the desire to have timing adjustment available. After all, isn't that the beauty of media servers?

Mac Pro 2018, 2GHz RAM, about 100 GB open storage space, only running QLab.
This actually might be part of your problem. According to their website, they recommend a minimum of 4GB of RAM. My guess is that the first few times that you run it, there is little to no stutter, but after a little bit, the stutter begins. This sounds like the computer is throttling the output due to lack of memory (this particular process might be using more than expected). In other words, it is building a cache for this effect and continues to pile it on in the memory and needs to be clear to keep it from stuttering. If you edit your image down to just the lungs, this might also help as it is not having to render unnecessary pixels. Something else is if you are able to fade out the effect and go back into it (go to a still image of the lungs as a pause between breaths).

I have only used Qlab for very basic video playback and never used Qlab4. I don't know if there is another effect that might work better.
 

matcreyn

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Correction: it’s got 4 GHz RAM. After trying these options, among others, deleting the cue and rewriting it fixed the problem. Still stutters with a radius above 35, but got it close enough to look good. Probably a glitch. Thanks all.
 

ruinexplorer

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Yay! I have had to do that with Isadora sometimes.
 
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JimmyM

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Mac Pro 2018, 2GHz RAM, about 100 GB open storage space, only running QLab when in show mode. Even when it’s the only file and effect running, it stutters in time with the effect. The greater the radius, the greater the stutter. The png itself is a long vertical file and the lungs are at the bottom, so I wonder if the effect is pinching the whole image towards its center, which is high above the visible lungs.
RAM is measured in gigabytes not gigahertz, I assume you are referring to the CPU clock speed. I don't believe you can configure less than 8 gb RAM on the Mac Pro.
 

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