Important Modeling Reminder: You Don't Need Watertight Geometry for All Environment Assets

One of the most common misconceptions in 3D environment modeling is that every prop and asset has to be a single, perfectly fused, watertight mesh from the very beginning.

In reality, for static environment assets you can and usually should build your environment meshes from multiple separate pieces of geometry then combine them into a single object at the end.

This approach will dramatically speeds up your modeling process, make things easier to build while producing often identical visual results in the end.

Video Tutorial

Real-World Example: Locker Asset

Take a typical school or gym locker:

• Main body
• Top vent details
• Number plate
• Indented padlock housing
• Padlock

Each of these elements were modeled as separate objects. Only after everything is perfectly positioned did I combine them into one object.

Real-World Example: Vending Machine

The same modeling method was used on the vending machine:

• Soda dispensing area and coin return were extruded from the main body (watertight) but could also have been separate similar to the locker
• Selection buttons are duplicated floating geometry
• Coin slot and bill acceptor are also separate floating pieces

Again, once combined into a single object, there is zero visible difference in the end.

When Does Watertight Geometry Actually Matter?

Only time watertight, fused meshes may matter are:

• Animated/deformable objects (characters, cloth, soft bodies, etc.) but even then, depends on what parts are moving
• Destructible meshes
• Physics simulations that require closed volumes
• 3D printing (where watertight is mandatory)
• Certain baking workflows (if getting light/baking errors then fuse them)
• Certain Sub-Div meshes or certain parts within them

But for 99% of environment assets and props that will never move or deform or break apart, these concerns don't apply.

Follow This Rule

Model your environment assets and props just like how they are created in the real world.

Most objects in the real-world are combined from multiple pieces, so model them that way too.

Recommended General Workflow

• Block out the asset using primitive shapes
• Model high-detail elements as separate floating pieces
• Position everything perfectly (be clean)
• Duplicate where needed (buttons, vents, etc.)
• Only combine into a single object when you're happy with the result
• UV
• Fuse/weld only if required by your pipeline or getting rendering/baking errors

Conclusion

Stop torturing yourself trying to Boolean or manually fuse every little detail into a single watertight mesh. For most static environment assets, floating geometry that gets combined at the end is not only acceptable but recommended.

Maya Home Study Course

If you want to learn how to model environment assets and props using the industry standard modeling software then look no further than this in-depth tutorial course "Maya Foundation: Home Study Course".

Get the Book »