Flow Maps in Houdini for Unity or Unreal
Channel: 3DGO
Date: 2020-10-27

I created a follow up video on how to render a CG Planet using flow maps here.
https://youtu.be/6ZL4JuBmOiQ

A quick introduction to the flow map tools in Houdini. We look at creating a flow map using the Sidefx labs nodes, exporting out the flow map texture using the map baker node, visualising the flow distortion in Houdini and exporting out the river mesh. 



Houdini can be used to create complex flow maps for creating rivers, lava and other fluid like movements in game engines. These techniques have been used to create flowing rivers in games like Horizon Zero Dawn. One of the first games to implement this technique was Portal 2. 

If you don't know what flow maps are take a look at this very nice explanation from Understanding Maps without code.
https://www.youtube.com/watch?v=NBEiTGHLkEo&feature=emb_logo

You can find a link to Alex Vlachos' Siggraph talk on implementing flow maps for water direction on Left for Dead and Portal 2  
https://steamcdn-a.akamaihd.net/apps/valve/2010/siggraph2010_vlachos_waterflow.pdf

More info on SideFx Labs (formerly the Game Dev tools) 
https://www.sidefx.com/products/sidefx-labs/

If you want to see how far you can develop these simple concepts check out this overview of how Ben Schrijvers used Houdini at Guerrilla Games to create a river system for Horizon Zero Dawn.
https://vimeo.com/216727778