Houdini Building Generator: Part 2

Welcome to part two of my Houdini building generator work process! In this article, I will continue to share my experience in creating this procedural tool.

After being stuck on the problems mentioned at the end of the previous article (if you are interested, please click here.), I took a different approach and utilized the original "Labs Building Generator" node, instead of the "Building Generator from Pattern" node. With this method, the parameters for the wall modules can be controlled within the generator. In this prototype tool, I have set up 3 types of walls to be laid out in the randomized building pattern.

With the parameters available in the Labs Building Generator, corner inputs are available in the default setting. After digging into examples from other creators and tutorials, I created some basic pieces that miter perfectly to the corners of the building.

As seen in the image above, walls A, B, and C are available on the control panel for wall variations. Within each wall type, controls for enabling the props scattering of air conditioners and awnings. Balconies can also be turned on and off with the controls, but I had only created one kind of balcony in this generator - that is also why I created an extra input for the "Additional Asset". It essentially has the same setting as the awning and is available whenever it is needed.

Here's a demo of the parameter controls in Houdini.

Let's dive into how I assigned materials to be available in the HDA for Unreal Engine. Previously, I experimented with the "unreal material" node which functions by referencing specific paths within Unreal Engine for materials. This method actually limits the versatility of changing materials inside the game engine. I took a more preliminary method of setting up shaders in the Material Network. Here's a breakdown of my process:

1. Create principle shaders within the Material Network and assign a unique name to each.

2. Insert a material node into the model and cross-reference the principle shader.

3. This setup provides an empty slot for assigning materials inside the game engine without going back to Houdini.

Here's a time lapse video of using the HDA in Unreal Engine 5.1.

Here are some sample buildings that generated with the tool, rendered in Unreal Engine.

Some of the things can be improved for the generator are as follow:

The ability to arrange various wall patterns instead of randomizing. The controls for the wall modules are still quite limited. It would be a lot more versatile if the generator allows external modules to be brought into instancing. I believe this limitation can be improved by integrating this set-up with the "Labs Building Generator from Pattern" sop.

The gaps in between the corner pieces and the wall modules. If you look closely to the building, you can notice the differences in texel density. The gaps can be eliminated by enabling "Scale modules" in the parameter controls, but that will also stretch the texel density of each module and result in uneven UV mapping on the building.

This Houdinibuilding generator is my first major project that focuses on the procedural work flow. It has been a few months of intensive "brain work-out" to wire my brain cells for the logic of Houdini. I actually enjoyed the thinking process a lot, especially the satisfaction of figuring out the problems and solving them. Lastly, THANK YOU SO MUCH, if you are reading my article til the end - feel free to leave my any kind of feed back! Although this concludes the final assignment that I submitted for my study at Seneca College, I will continue to develop this tool and improve it.