It’s been nearly a full month since my last update, so what have I been working on?
The last few weeks have been incredibly busy. I’ve had several interviews and job application submissions. My gallery and design pages received some helpful updates. I’ve successfully built a standardized data format for a visualization project and introduced some of my fellow interns to the history and purpose of data visualization, and its role in matters of social justice and equality. I’ve also continued to make leaps and bounds on my 3D character work.
I’ve resolved the primary issue that was plaguing me early on in this project: mesh topology.
To be efficient for a game engine, it’s important to resolve mesh geometry with minimal faces. Unreal Engine 5 supports a new level-of-detail automation called “nanite,” which allows 3D modelers to create elements with a virtually unlimited number of faces (geometric detail). This does not seem to work with animated characters, however — if you know a way around this, please send me a message!
A “face,” in this context refers to a plane that has 3 (tris) or more points. Ideally, the geometry should have faces with 4 points (quads). While modern engines and graphics hardware have gotten significantly more advanced since the early days of 3D gaming, it’s nevertheless still important to avoid models with excessive polycounts (the sum total of faces in a model).
The challenge with my model is that it requires several tangent geometries that intersect with a central body. Image if you were modeling Tree Character, and you need to cover the various branches with leaves, blossoms, or pine needles. Blender can easily generate these elements using weighted vertex mapping and particle systems (hair). The difficulty, however, comes from trying to export this data for use in Unreal Engine.
Unreal Engine supports FBX models for import, but FBX models do not support shape keys. By default, Blender applies Particle System modifier as a shape key. You can, however convert particle instances into their own individual body/mesh component in Blender prior to export. This works, Unreal will interpret the model as being several individual bodies with shared coordinates. When exporting this type of arrangement, animation rigs cannot deform the free meshes — your leaves (or whatever) will stay in place while the rest of the tree animates.
You may already be thinking to yourself, “why not just combine the meshes?” And since the beginning of this project, I anticipated that this might be necessary at some point. The challenge then is how to create a combined mesh that is free of visual artifacts. Additionally, the boolean modifier in Blender only allows you to select a single target body to combine (union).
Thankfully, there is a Blender add-on for this last issue: BoolTool.
Suppose you want to combine all of your individual leaf meshes to the main tree body, but you know it would be insanely time consuming to go through the tedious sequence of selecting each leaf, one at a time, applying the modifier, creating a new modifier, and repeating that x700.
You could try writing a script, to automate this process, but you’d need to write it in python, and that would be a can of worms unto itself. You can already imagine the mission creep setting in…
BoolTool makes this process dead simple. You just select the mesh body you want everything to join with (active object), and then select all of those other meshes. Go to the BoolTool menu and select “union.” You may think that Blender has crashed, but give your computer a break. Grab a cup of coffee, meditate, embrace the here-and-now… *BING* [Your mesh combine operation is complete!]
Assuming you created an efficient mesh, primarily out of quad faces, with intersecting meshes containing the same number of vertices, then you should have a single mesh geometry that is ready for rigging and animation.
I’ve tried dozens of other approaches so far, and this method produces the best results all-around: faster, easier to execute, high fidelity, and with the lowest poly count.
I’m still working out the kinks on my current model, and the animation sequences will be a next-level creative challenge for me (I have a lot of inspiration and ambition on this front), but I feel confident in the current direction, and early tests have been quite promising.
I’m also starting to make simple prototypes for augmented reality, and will add some notes about that later this month.