[Anat3] Rewrote MRQ section (incl. latests devs)

_posts/2024-01-01-anatomy-3.md

@@ -51,7 +51,7 @@ So I used a random rest stop from around my childhood home as reference, and jus
 
 Then I imported that in Unreal, did a bit of back and forth between the tools to fine tune some things (mostly lane markings). In Unreal, I added some props and foliage and that was it!
 
-Shout out to [Marketplace](https://www.unrealengine.com/marketplace) creator [Der Sky](https://www.unrealengine.com/marketplace/en-US/profile/Der+Sky), whose "[European Collection: French Highway](https://www.unrealengine.com/marketplace/en-US/product/european-collection-french-highway)" product is absolutely perfect for this use case. Go check their products, if you need road props and signs, they most likely have what you want.
+Shout-out to [Marketplace](https://www.unrealengine.com/marketplace) creator [Der Sky](https://www.unrealengine.com/marketplace/en-US/profile/Der+Sky), whose "[European Collection: French Highway](https://www.unrealengine.com/marketplace/en-US/product/european-collection-french-highway)" product is absolutely perfect for this use case. Go check their products, if you need road props and signs, they most likely have what you want.
 
 # Scenario
 
@@ -123,16 +123,18 @@ One little caveat is that this doesn't handle cars already being on the overtaki
 
 Since this scenario is fully-autonomous with no user input, and the target hardware is a single computer with three monitors, we can render the scenario into a video instead of having it run in realtime. This has multiple benefits: improved visual quality, perfect framerate, etc.
 
-This part turned out to be quite complex, and for a rather unexpected reason: sound!
+This part turned out to be quite complex, and I ended up doing a lot of back and forth between the legacy renderer, and the newer [Movie Render Queue](https://docs.unrealengine.com/5.3/en-US/render-cinematics-in-unreal-engine/) (MRQ). In the end, I chose MRQ, but the process wasn't as smooth as I hoped it would be.
 
-At first, I really wanted to try out the new [nDisplay Movie Render Queue pipeline](https://dev.epicgames.com/community/learning/tutorials/9VX5/unreal-engine-export-ndisplay-renders-using-mrq), which sounds exactly like what I want. Even though we have a single computer, we still have three displays, so being able to correctly configure viewports would be great.
+Overall, Movie Render Queue is really an improvement over the legacy pipeline, and using it is pretty straightfoward. One thing that was really appealing was the [nDisplay Movie Render Queue pipeline](https://dev.epicgames.com/community/learning/tutorials/9VX5/unreal-engine-export-ndisplay-renders-using-mrq), which allows rendering video for all viewport of any [nDisplay](https://docs.unrealengine.com/5.3/en-US/ndisplay-overview-for-unreal-engine/) cluster.
 
-However... It seems that [Movie Render Queue](https://docs.unrealengine.com/5.3/en-US/render-cinematics-in-unreal-engine/) doesn't support [spatialized sounds](https://forums.unrealengine.com/t/cant-render-out-sound-from-ue5-using-render-queue-or-movie-scene-capture-reliably/577782), which obviously is an issue for us, as all our sounds are spatialized.
+However, since the MRQ-nDisplay is a relatively new addition to Unreal, it has some limitations that I discovered along the way. First, the [command line](https://docs.unrealengine.com/5.3/en-US/using-command-line-rendering-with-move-render-queue-in-unreal-engine/) doesn't seem to support it, which is a shame because I had already taught our [Discord bot](/whats-new-2023-05/#bots) the new `!render` command. Second, the [encoder](https://docs.unrealengine.com/5.3/en-US/cinematic-rendering-export-formats-in-unreal-engine/#commandlineencoder) also doesn't seem to support nDisplay rendering, meaning that I had to encode myself (which is rather easy using [FFmpeg](https://ffmpeg.org/)). But since I couldn't use the command line in the first place, I couldn't automatically trigger the encoder afterwards, so nightly renders were impossible.
 
-So I went back to the [legacy renderer](https://docs.unrealengine.com/4.26/en-US/AnimatingObjects/Sequencer/Workflow/RenderAndExport/RenderMovies/), which is way less fancy, doesn't have nDisplay support, but at least works with spatialized audio. Or at least, that's what I thought? I didn't have much time to investigate the issue, but the generated sound track was captured *after* the end of the level sequence, which meant the sound was pretty useless since it didn't actually record anything happening during the video.
+And last but not least, Movie Render Queue doesn't support [spatialized sounds](https://forums.unrealengine.com/t/cant-render-out-sound-from-ue5-using-render-queue-or-movie-scene-capture-reliably/577782), which obviously is an issue for us, as all our sounds are spatialized. As a workaround, I de-spatialized all ego-vehicle sound, and said goodbye to all other vehicles' sound (which is not that big of a deal for a highway scenario).
 
-In the end, I decided to switch back to Movie Render Queue and de-spatialize all ego-sound so that they would be recorded. That meant I lost all other sounds, but since it only included non-ego vehicles, it's not that big of an issue for this highway scenario.
+So the rendering required more work than expected, but the end result was really good. It seems Epic has a lot more work planned for the Movie Render Queue, including a very interesting [Movie Render Graph](https://portal.productboard.com/epicgames/1-unreal-engine-public-roadmap/c/1365-movie-render-graph).
 
-And as usual: clicking buttons to render, package or build isn't my thing, so our [Discord bot](/whats-new-2023-05/#bots) learned the new `!render` command to render a [Sequence](https://docs.unrealengine.com/5.3/en-US/unreal-engine-sequencer-movie-tool-overview/). I could have gone a bit further and have it take as argument the scenario CSV file, so that researchers could just type `!render my_scenario.csv` and get a video without ever touching Unreal. But for now, it's definitely not worth implementing that, so maybe for the next project!
+# Conclusion
+
+This project was a lot of fun to make, and I learned quite a lot of things in both RoadRunner and Unreal. I feel like a broken record, but those two tools really are empowering us so much to do amazing things. I already started using my new MRQ skills: for documentation purposes, I decided to render movies of all our current (and future) scenarios. See you for the next one!
 
 [vd]: /virtual-driver/