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Blender 5.0+ Updated

Blender 5.0.1: Precision Modeling for Roblox

Step-by-step guide from basic geometry to professional exporting.

In professional modeling, working with numeric input is essential instead of dragging with the mouse.

  • Unit System: Go to the Units section in the Scene Properties panel. Ensure Unit System: Metric and Length: Meters.
  • Sidebar (N-Panel): Pull the small arrow on the right or press N. The Dimensions part in the Item tab shows the real dimensions of the object.
  • Numeric Input: When moving (G), rotating (R), or scaling (S), you can give exact values by typing numbers immediately after (e.g., G X 5).

The cleanest way to create oval wall edges for Roblox is to split a Cylinder.

  1. Add Object: Shift + A -> Mesh -> Cylinder.
  2. Determine Dimensions (Critical Step): A small panel opens in the bottom left corner as soon as you add the cylinder: "Add Cylinder".
    • Expand the Panel: If the panel is closed, click the small arrow next to it.
    • Numeric Input: Enter values like Vertices: 64, Radius: 2m, Depth: 4m.
    • Caution: This panel disappears when you click elsewhere or move an object. If you miss it, delete and re-add the object.
  3. Later Scaling (N-Panel): Press N while the object is selected. You can change X, Y, and Z (height) values from the Dimensions part in the Item tab.
  4. Precision Cutting (4 or 8 Pieces):
    • Edit Mode: Press Tab.
    • Top View: Press Numpad 7 (You must look from exactly above).
    • X-Ray Mode (Critical): Press Alt + Z. This mode allows you to select points behind the object.
    • B Key (Box Select) Usage:
      1. Press B. Your cursor will turn into a crosshair with dashed lines.
      2. Draw a square around the parts of the cylinder you want to delete.
      3. Release the left click. Selected areas will be orange.
    • Deletion: Press X and select Faces.
    • Result: The remaining 1/4 piece will be a perfect oval corner of 90 degrees.
  5. Adding Thickness (Solidify): If you want wall thickness, add Modifier Properties -> Add Modifier -> Solidify. Enter a numeric thickness like 0.2m.

Be precise when locking objects to each other (Snap) instead of dragging randomly with the mouse:

  • Snapping: Click the "Magnet" icon at the top center. Select Vertex or Edge from the menu.
  • Absolute Increment Snap: If you want the object to sit exactly on the grid, select Increment in Snap Target and check Absolute Increment Snap.
  • Moving: If you hold Ctrl while pressing G, the object will snap to the grid.

To prevent Roblox from seeing complex models as simple boxes, you must use the UCX naming convention.

  • Invisible Barrier: If your main model's name is Room_Wall, the collision model's name must be UCX_Room_Wall.
  • Collision Model (Simple Geometry): The model starting with UCX should only be the "rough" version of your main model. Use simple cubes or low-poly cylinders.
  • Export: When you select both objects and export, Roblox automatically detects it as collision data.

Follow these steps to avoid scale issues when importing into Roblox Studio:

  • Apply Transform: When finished, press Ctrl + A in Object Mode and select All Transforms. (Scale must be 1.0).
  • Export Format: File -> Export -> FBX (.fbx).
  • Export Settings: Check Selected Objects, set Apply Scalings to FBX All, and Axis to Forward: -Z Forward, Up: Y Up.

Always check this list before sending your model to Roblox:

  • Invisibility Issue (Normals): If your model is one-sided or invisible, use Alt + N -> Recalculate Outside in Blender.
  • Light Leaking: Use the Solidify modifier to give thickness to walls.
  • Apply Modifiers: Always Apply all modifiers before exporting.
  • Size Issue: If the object is too small/large, you likely forgot Ctrl + A -> Scale.
  • Invisibility Test: Use Backface Culling in Blender to see how it will look in Roblox.