Product work | Building tool
I started my work by trying to solve the last week issue (the system did not auto-populate the building with the modular pieces). I found two potential solutions to the issue:
Using Unreal Engine data tables (simply put, they are spreadsheets containing all the necessary information, which in my case was information about the modular pieces) as a reference in Houdini for the meshes that have to be used
Using individual elements from Unreal Engine as a reference in Houdini for the meshes that have to be used
I tested the data tables method first because it allowed for less future manual work and more proceduralism. According to this method, a "structure" for the data table had to be created first. This "structure" defined the elements and type of data that would be accesible within the data table. Next, all the modular pieces had to be added to the data table and referenced in Houdini using an "Object merge" node (this node allows to merge multiple meshes within one node).
The issue was how to make the Houdini system randomly pick a mesh from the "Object Merge" and not display all the modular pieces listed in the data table at once.
I tried various methods, such as using an "Attribute randomize" node to randomize the reference within Houdini, or using "for each loops" to make the system pick a different mesh for each point, but all the attempts failed. I asked the art lead of our team for help, but he could not solve the issue.
Under these circumstances, the most optimal option was to test the second method. This method involved referencing in Houdini all the necessary meshes via the node "Labs Instance Attribute". Parameters such as "weight" (which determine how big is the probability that this specific variation, let's say of the roof, will be picked and displayed onto the point in Unreal Engine), could be exposed in Unreal Engine for further necessary tweaking.
Per general, the method works well, but the system seems to favorize some meshes despite the weight. Also, another way to improve the system would be to make the system assign a random number for the number of floors assigned to each building. I looked into methods of achieving this but they all failed. Most of the methods included replacing the number of floors number with a Houdini variable such as $F (which makes a reference to the current frame number). The issue with this is that these variables, while relevant for Houdini, are unknown to Unreal Engine and cannot be read by it. Another method was to create an attribute that would represent the number of floors, then using an "Attribute randomize" node to randomize the attribute. It did not work, but after discussing the issue with the art lead I understood that I was not referencing the randomization properly. We found the proper way to reference it in Houdini which has the following structure: "detail(surface_node, attrib_name, attrib_index)". The method worked within Houdini, but it did not work in Unreal Engine.
I decided to email on Monday the professional that I met during the Houdini masterclass to ask for help to address the issues I encountered.
Product work | Range Shader
This week I also started to work on a range shader for our product. First, I clearly defined what the shader components are and what it needs to do with the designers. The shader has to illustrate within what point area a house is (3 points, 2 points or 1 point). Also, we discussed the possibility of having an outline around different point areas to help divide them better.
As the range shader has to be an overlay over the existing materials, I looked into how to achieve this. A powerful way would be to use the new Unreal Engine "substrate materials", which allows for stacking of multiple materials within one material. Unfortunately, this feature is still experimental and not recommended for product use. I will have to look onto other options to create the overlay.
I also started to gather some visual reference for the shader, that I will ask feedback on from designers next Monday.
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