Empowering Artists with Intuitive Crowd Tools: Midgård at Nordisk Film Shortcut
Date of Project: November 2020
At Nordisk Film Shortcut, adding crowds was a recurring task for film and TV productions. However, at the time, using Houdini’s native crowd tools required an in-depth understanding of low-level nodes, making it inaccessible to many artists. To address this, I developed Midgård, a custom suite of crowd tools designed to simplify the process and enable non-expert users to quickly create complex crowd shots.
By building high-level custom nodes with intuitive interfaces, I made it possible for any artist to set up and control crowds efficiently. The tools operated entirely within Houdini’s geometry (SOPs) context, avoiding the need to dive into simulation contexts (DOPs) and further streamlining the workflow.
Core Functionality and Features
1. User-Friendly Setup
Artists could bring in agents from disk, complete with various animations, and quickly place them using a straightforward interface.
Shading variations for agent clothing were easily assigned using custom CVEX shaders. These allowed for automatic variation in colors and textures, so artists could focus on the creative aspects without worrying about technical complexities.
2. Flexible Placement Tools
Agents could be placed by drawing directly on surface geometry or using curve paths for them to follow.
Geometry could also be added for agents to avoid, ensuring realistic interactions with the environment.
Artists could assign animations like walking, running, or jogging with just a few clicks, or use “states” like “seek” to guide agents to specific locations.
3. Automation and Efficiency
Shelf tools written in Python allowed for quick setups, enabling even new users to get started within minutes.
A robust pipeline for adding new agents and animations ensured the system could be easily updated for new projects. A simple CSV file stored information about agents and animations, and with the press of a button, they were integrated into the system for immediate use.
See top video showcasing the shelf tool functionality and agent placement workflow.
Bottom video shows agent setup with easy shading variation, that is effectively applied at render time, utilising shaders i wrote in CVEX.
The video below shows early tests of the tools. Sorry for the low video quality, but the source is a company wide presentation of the tools, for all of Nordisk Film, that was streamed on Microsoft Teams.
Expanding to New Needs: Birds in the Netflix show Elves
As the tools evolved, I extended their functionality to handle shots involving birds for the Netflix series Elves (Nisser). These ranged from small flocks of 3 birds to scenes featuring 600 birds. Using the same principles of simplicity and flexibility, the bird tools allowed for quick setup and realistic behavior.
Challenges and Innovations
Developing Midgård presented several challenges, particularly in making the tools robust and intuitive for non-experts. Some of the key challenges and solutions include:
Enabling Non-Experts: Creating an intuitive interface that abstracted the complexity of Houdini’s native tools required several iterations and extensive testing with users. Feedback from artists was invaluable in refining the workflow and ensuring the tools were accessible and efficient.
Flexibility and Robustness: The tools needed to accommodate a wide variety of scenarios, from standard crowd setups to new functionality like birds. Continuous development and adaptability were critical to the system’s success.
The tools developed by SideFX three years later for Houdini 20, bear a strong resemblance to Midgård. This similarity reinforces that the design choices and workflow innovations made during this project were on the right track.
Pipeline and Reusability
One of the most significant achievements of Midgård was the flexible pipeline built around the tools:
Adding new agents or animations was as simple as updating a CSV file with basic information like file paths, labels, and categories. This automation allowed agents to be easily repurposed and reused across multiple productions.
Artists could quickly customize agents by assigning objects like hats, canes, umbrellas, and swords, ensuring that each crowd setup met the specific needs of the show.
This pipeline made the tools not only powerful but also incredibly efficient for large-scale productions.
Empowering Artists
A personal highlight of this project was seeing a colleague, new to Houdini and entirely unfamiliar with crowd systems, create a shot featuring hundreds of autonomous agents in half an hour. This moment underscored the success of the tools in empowering artists to bring their visions to life without requiring deep technical expertise.
Conclusion
Midgård transformed how crowds were handled at Nordisk Film Shortcut, enabling faster, more flexible, and artist-friendly workflows. The resemblance of SideFX’s Houdini 20 tools to Midgård serves as validation of the design principles behind this project. From large-scale crowd shots to intricate bird flocks, these tools streamlined complex processes and allowed artists to focus on storytelling and creativity.