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Vision Video Rendering Time Dilation

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Good morning, all.  I've been working from home trying to get some programming done.  I've done a timecode show using an ETC Eos, and rendered out a DMX file but have run into several issues.

  • The biggest issue is that when I render out a full video, the timing of the video is much slower than the original programming.  IE, a song might be 8:03 long, but the rendered video is 8:08, so when I pair the video up with the sound file in Premier to render out a finished video, the video is out of sync and only gets worse the longer the video is.  I've tried rendering at different frame rates, different resolutions, and different levels of quality in both Vision 2019 and 2020 and on multiple machines, but never once gotten the lighting to sync with the original sound.
  • In the process of trying different export options, I also had a problem with trying certain frame rates.  Any time I chose 48 frames per second and clicked "Render," the dialog box would close but would not start rendering.  I have only been able to render at 30 or 60 frames per second.
  • I've also had several problems where some fixtures don't render in the video in some renders.  When I playback the DMX stream, everything matches the console output as originally recorded, but the video rendering doesn't have the D60 back light, the Colorforce 72 cyc lights, Lustr 2 front lights, or X4 Bars.  But the Axiom Beams, Quantum Spots, Mac Vipers, and Magic Panels all work flawlessly.  After the rendering is complete, the fixtures that did not properly render stop responding to DMX until I restart the Vision software.  It's a bit of a bummer in that I don't know whether or not all of the lights are properly rendered until after I've spent the couple of hours it takes to render.


My system is a Surface Book 2 with an Intel Core i7-8650U CPU, 16 gb of RAM, and an NVIDIA GeForce GTX 1060.


- Jesse

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  • Vectorworks, Inc Employee

The main factors that affect rendering performance in Vision are the number of light emitters, your graphics preference settings (in Edit menu, under Vision preferences) and the haze settings (in File, document settings or in the Properties pane if you have Root selected in the scene graph).

An important note, the number of emitters is not the same as the number of fixtures in your design, a fixture can have multiple emitters, for example a GLP X4 bar 20 has 10 emitters.

The graphics settings that have the biggest performance impact are shadow quality, surface light quality, dynamic shadows and resolution quality

The haze settings affects performance depending on both the type of haze you use (low res-low impact, high res 4D-high impact) and the amount.


From your system specs and description, it sounds like your design is fairly large (emitter wise) and you have the graphics preferences set too high for your system spec. The biggest give away is that you have fixtures not showing in your movie.

The easiest way to check whether you can render a movie with your current settings (graphics (including resolution) and haze) is to try rendering a single image with those settings. If the image renders successfully then you will be able to render a movie successfully with the same settings.


Regarding frame rates, unless you plan on playing the rendered movie in slow mo, I would recommend using either 24 fps (used for most films, TV shows and is regarded as the most 'cinematic') or 30 fps (used for live TV, sports, soap opera' and in video recording apps). This will help to reduce the movie rendering time and will not affect the quality of the movie.

If the timing or frame rate choice  issues continue after adjusting your settings comment here and I will open a bug report

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Jesse, we almost have the same name.  That's kind of neat.


When I was exporting the video on the project, I was always rendering out a still before rendering the video to check camera shots, since my monitor in full screen was different than my rendering aspect ratio and always saw the full rig in the still.  But you are quite correct, there is a large number of emitters in the file.


So I stripped out everything except the D60 top light from the file and made a quick cue stack to easily check the timing.  The lights all flash on for one second, off for one second for five minutes, with them flashing red every 10 seconds, and at each minute, a different column stays on in blue.I rendered out a file at 24 FPS and one at 30 FPS.  The DMX file comes in right at 5:05 in length, but the 24 FPS video is 5:03 in length, and the 30 FPS video from the same DMX file is 5:08 in length.


This is a similar amount of "drift" that I saw during the show exports.  I was able to get around it by placing a "blip" cue (top light at full in a 0 count, out in a 0 count after a 0.5 follow) at timecode 00:00:05:00 and a similar one at the end of the cue stack.  In Premier, I make sure the first blip lines up exactly at 00:00:05:00, then use the stretch time feature to make the end blip line up with the timecode in the console and re-render the video.  The good news is that the "drift" is at least a consistent rate.


The v3d file is attached.  I can't attach the video or DMX files to this, but assuming you're able to access Google Drive links, the DMX file can be found here, and the 24 FPS video can be found here.


Notes on the video: you'll see the starting "blip" at 00:00:04:12.  This lines up with timecode 00:00:05:00, the timing check begins in earnest at 00:00:09:12 in the video, which should line up with timecode 00:00:10:00.  As originally recorded in the console, at timecode 00:05:05:00 the lights will cut to black, which occurs at 00:05:02:02 in the video.


These tests were done on Vision 2020, version, DMX provided by ETC Eos version 2.9.1.


While I have your ear, as a feature request, could we get a DMX trigger channel for the DMX Recorder?  CueServer, DMX King, and Alcorn McBride Light Cue all have a way to do this, and it makes streaming DMX a lot easier since I can sync it to a cue in my console rather than starting timecode and pressing a button in the software to start recording.


Thank you for taking the time to look through this.


- Jesse

Timing Check.v3s

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  • Vectorworks, Inc Employee

a possible cause of the out of sync rendered movie is that the the Vision previs renderer and the dmx recorder are run on the same processor core. If your graphic settings were too high when you made the original recording, the DMX recorder may have missed some frames of the DMX signal because of  this. Try rerecording the DMX in an empty file/scene and using the new recording for rendering a movie in the original file.

If that doesn't fix the issue give me a shout and I will get the Vision team involved


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Just gave this a shot and had the same results.  The final video export is shorter than the original DMX file.  When syncing up the starting "blip" to 00:00:05:00, the final blackout occurs at 00:05:02:16 rather than 00:05:05:00 as it was originally programmed.


Also, if this was the issue, how would it explain the difference in video length between 24 FPS and 30 FPS exports with the same DMX file (5:02 with 24 FPS, 5:08 with 30 FPS).


New video file can be found here, new DMX file can be found here.


Thank you again for looking into this.


- Jesse Cogswell

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  • Vectorworks, Inc Employee

Hi Jesse, developer on Vision here. I looked into in and the time sync issue is definitely a bug on our end. One thing that may work until we get it fixed is to use 25 or 50 fps. The issue seems to be related to the number of milliseconds per frame not being evenly divisible in most of the frame rates. 25 and 50 do not have that problem, so they may work out better for you until we can get the fix into a release.

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  • 4 weeks later...

Following. Same issue. DMX source is also Surface Book 2.


I've tried rendering on a couple of different machines (Razr then Alienware) and am getting the same time dilation issue when rendering. I have to use Premiere to adjust the video clip speed.


This is only speaking for the video clips that Vision will render. I drew (32) X4 Bar 20's, and neither a Razr nor Alienware will render a movie with those fixtures on in medium-medium-medium quality at 800x600 at 30FPS.

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  • Vectorworks, Inc Employee

We have a fix for this time dilation issue that should go into our next service pack release SP4. For the time being 25 and 50 fps seem to not exhibit this issue so we recommend using one of those output settings until the fix is released.

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  • Vectorworks, Inc Employee

@allannathan what was the spec of the different machines?

 32 glp bar 20's works out at 320 emitters for working the correct settings to use for rendering.

The best way to check if you can successfully render a movie is to try rendering a still using the same settings as you want to use for the movie, if it renders correctly then you should be able to render a film.

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The movie renders until about 4 seconds (of the mpg) until Vision crashes.




Razer Blade Pro


17.3" 4K/UHD

Intel Core i7 7th Gen 7820HK (2.90 GHz)

NVIDIA GeForce GTX 1080 32 GB Memory 512 GB SSD



Product ID: 00325 81531 75966 AAOEM

Intel Core i7-9700 (3.00 GHz)

NVidia GeForce RTX 2070



Edited by allannathan
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After switching to exporting at 25 FPS, I have had no issues with the time dilation, making Premier setup a breeze and the final export from Premier faster and cleaner.


As for fixtures disappearing during rendering, I have had the best luck with starting the render process immediately after opening the file without turning on lights or rendering a still first, as many times I've rendered the still first with no problems only to have the two hour rendered movie missing whole fixture groups.


My standard work flow has been as follows:

  1. Program with a "Low Res" setting (800x600, everything set to low except Texture Quality so that I can see gobo edge settings)
  2. Open a blank Vision file and record the DMX
  3. Close and restart Vision
  4. Immediately render movie with a "High Res" setting at 25 FPS without touching anything else in the file
  5. Use Premier to sync up sound and do final export

I have also found that I have had higher success in exporting if I have my battery settings set to "Best Performance" before opening up Vision to do video rendering.

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