Solid Modeling – 3D Modeling With Parts
Solid Modeling – 3D Modeling With Parts
Solid modeling allows you to make complex parts in Roblox. Starting with very simple parts (blocks, spheres, wedges, and cylinders), it’s possible to create almost any shaped object imaginable!



The main advantage of solid modeling is that objects created become single parts. This can result in a significant part count reduction and improve game performance.
Union
The main function when using solid modeling is called Union. To use it, select the parts you want to combine and click the Union button in the Model tab. This will create a new part called Union (which you are free to rename).

DataModel
.Negate
Solid modeling allows for more than just joining two parts together! Parts can also be removed from other parts using the Negate button. To use it, select a part and click the Negate button in the Model tab.

This will convert the part to a “negative part” (it will turn red and translucent to indicate this). Now, whenever this negative part is unioned with a normal part using the Union tool, the section of the parts that overlap will be cut out.
Separate
If you don’t like the result of a union, you can undo it by selecting the unioned part and clicking Separate. This will break the union apart so you can resize and rework the construction.

Solid Modeling Limitations
- There is a limit to how many parts can be generated. If a union operation would result in a part with more than 5000 triangles, it will fail and Studio will alert you to the error in the Output window.
- A part made with solid modeling can only use one color and material. If you union two parts with different colors/materials, the result will use the characteristics of just one of the parts.
- A unioned or negated part can only be scaled uniformly (all of the dimensions must be scaled at the same proportion). If you need to change the size of just one part in a solid model construction, it may be easier to un-union that part, resize it, and then redo the union process.
Level of Detail
By default, solid-modeled parts will always be shown in precise fidelity, no matter how far they are from the game camera. This improves their appearance when viewed from any distance, but if a place has a large number of detailed solid-modeled parts, it may reduce overall game performance.
To dynamically control a solid-modeled part’s level of detail, change its enum/RenderFidelity|RenderFidelity
property to Automatic. This will cause the part to be rendered at a different level of detail depending on its distance from the camera:
Distance From Camera | Render Fidelity |
---|---|
Less than 250 studs | Highest |
250-500 studs | Medium |
500 or more studs | Lowest |