How To Make Proper Post-editing Motion Blur

This blog post will discuss the way you can get proper motion blur in your videos. This will talk about how to do it in Sony Vegas Pro. This is just what I know from experience with working on it and what I read on the internet, so use it as you will

If you want to read up on the thing yourself on how to do it in stuff like VirtualDub, VirtualDubMod or Adobe Premiere or you don't wanna read this and just want to get to the steps immediately, go to this link below:

https://developer.valvesoftware.com/wiki/Demo_Video_Creation

This is for the Source Engine but scroll down and you will see on how to do it in a video editing software of your choosing with any game as long as they allow you to export in-game recordings at specific frame-rate/have a beefy PC which can be way over a specific margin, allowing you to cap the in-game frame-rate the game and record the game while having the frame-rate you have specified 100% of the time.

The way you can get good motion blur in your game video is to record the game at high FPS(or export giant amounts of frames at a specific frame-rate). This varies on what FPS you have decided to have the video to be exported as, since all the frames will be used to be resampled to create a smoother moving image.

The Source Engine motion blur that's in the game by default is trash, it gets enabled when you start moving your camera, falling while looking down or up at a specific speed, this is enviable due to the nature of it looking out of place and ugly. However, you can use a feature available in the engine that allows you to export demos at a specific frame-rate at the cost of storage space depending on what size your in-game resolution and your specific frame-rate you want to export the demo at is.

A video rendered at 300 FPS at 640x480 resolution with the length of ~35 minutes ended up consuming ~400 GB on my HDD, luckily, since Source Engine can allow you to record specific demos, I was able to have a work around for that space limitation and record demos separately, render them in Vegas Pro and then delete the entire image sequence, leaving me with a video I could use in the project without having my game dying.

To export demos in the Source Engine, you need to disconnect from the map you're on, yes, I know that's a multiplayer term but technically when you're in-game you are actually on a game server. After that, you need to turn on sv_cheats. Now the main part of exporting begins.

1. Type in "host_framerate X", X being the frame-rate you want the game to export the demo at, after that, you should set what resolution the game will export it in, just change the game resolution and that's it.
   Now, before you start recording, please check how much space you have on your storage device where the game resides in since its the major factor in this. A demo exported in 300@640x480 that's the length of 15 minutes takes up ~150 GB.
2. Type in "startmovie X_", this is the name of your image sequence that you're gonna export, the underscore is VERY IMPORTANT, it will be easy on your nerves to import it all into Vegas.
3. Type in the demo you want to record. Take a break while its exporting, it will take a long time.
4. Once it finishes exporting, type in "endmovie" to have the audio file be finalized
   

Congratulations, you have officially wasted all of your storage space for a export of your demo. Let's get into the editing part

Create a project in Vegas Pro and set the parameters to be the same as the settings you exported the demo at. Make sure the video is not interlaced and is set to "Progressive" with sampling set to consistent and not smart or else it will look ugly.

Once you do that, go to File -> Import -> Media, go to the hl2 folder(or the mod of your choosing that you had the demo exported on) and select the FIRST FRAME of the image sequence and then toggle "Open still image sequence", let it think for a bit and then make sure the range is correct. After that, press "Open".

After that, set the settings for the image sequence, make sure the frame-rate is at max/the same as the demo(some Vegas versions don't allow having the frame-rate set over 120 FPS.). Drag your image sequence into the timeline and put in the audio file. Now comes the crucial part

The Source Engine freaks out a bit in the beginning of playing the demo and it will be slightly offset, play around with the video scale and make sure it matches the audio file as much as possible in terms of timing. Please set your preview quality to "Preview (Quarter)", this will make playing the demo painless.

After all that, export the video in AVI if you want it to be 1:1. Once you do that you can delete the image sequence or keep it for future purposes, just make sure you still have the original .dem files to re-render again in the future.