Primitives¶

Primitives are the starting point for most models. Pick one in the Create tab of the Modelling panel, then draw it in the Scene view.

Available primitives¶

The buttons under Spline Based create meshes from a spline. Select a single object with a spline first:

Stairs

Creates editable stairs along the selected spline.

Tube

Creates an editable tube along the selected spline.

Surface

Creates a surface that fills the area enclosed by the selected spline. See Surface.

Stairs, tubes and surfaces rebuild whenever you edit their spline. Their settings (steps and caps for stairs, sampling, roll, twist and corner rounding for tubes) are in the Editable Primitive inspector.

Drawing a primitive¶

1. Click a primitive in the Create tab.
2. Drag in the Scene view to draw its footprint. Hold Ctrl while dragging to keep the footprint proportional.
3. For shapes with height (cube, cylinder, cone and so on), release the mouse, move it to set the height, and click to finish.

The Create Mesh Options panel appears in the Scene view while you draw. Its title names the primitive (for example Cube Options). It shows the dimensions (Width, Depth, Height, Radius...) and the detail settings (Subdivisions, Sides, Segments). You can type exact values there.

Some primitives have extra options in that panel:

Cylinder

Inner Radius opens a hole through the center (0 makes a solid cylinder). Arc Degrees sets the start and end angles, for a partial cylinder.

Torus

Radius goes to the center of the ring, and Thickness is the diameter of its round section. Arc Degrees works as for the cylinder.

Arch

Radius, Wall Margin (the distance from the opening to the outer border of the wall), Thickness, Arc Degrees and Segments. Radial Edges divides the front and back walls into faces between the arch and the border. Add Front Wall, Add Back Wall, Add Inner Band and Add Wall Caps choose which parts are built.

Create in that panel builds the primitive again at the last footprint you drew. If you haven't drawn one yet, it uses the typed dimensions at the world origin. Cancel stops the creation.

Free-form¶

Free-form draws a flat polygon point by point:

• Click to add each point.
• Press Enter or right-click to finish the shape.

Creation options¶

Plane, Orient and Orient to First Step are in the Create Mesh Options panel. Snap First Point to Surface is there too, and under Create Options in the Create tab, next to Material and Vertex Color.

Plane

The plane the footprint is drawn on: XZ (the ground), XY, YZ, or Face Surface, the surface under the cursor.

Orient

How the new object is rotated: aligned with the plane it's drawn on (Placement Plane), so its height follows that plane's normal, or upright along the world axes (World Up).

Orient to First Step

The first drag sets the direction of one side, and a second step sets the depth. Useful for drawing boxes that are rotated to match something already in the scene.

Snap First Point to Surface

Places the first point on the surface under the cursor, even if snapping is off. The following steps stay on the plane started by that first point.

Material and Vertex Color (under Create Options)

The material and vertex color given to new meshes.

From the GameObject menu¶

GameObject > World Toolkit > Modelling creates primitives without drawing them:

• Plane, Cube, Circle, Cylinder, Cone, Sphere, Torus, Custom Polygon and Arch are created with their default size, at the center of the Scene view, or as a child of the object you right-clicked in the Hierarchy. They get the Create Options material.
• Free Form starts drawing a Free-form shape in the Scene view.
• Stairs from Spline, Tube from Spline and Surface from Spline work like the Spline Based buttons, on the selected spline.

Surface¶

Surface fills the area enclosed by a spline path. Select the object with the spline and click Surface: the surface is created as a child of the spline object and fills its first path that has at least three knots.

Its settings are under Surface in the Editable Primitive inspector:

Spline and Path Index

The spline object, and which of its paths to fill.

Fill

How the inside is meshed: Quad (a grid of square cells Quad Size wide, cut to the outline), Hex (hexagonal cells of Hex Size), Delaunay Subdivisions (triangles about Subdivision Size wide, with heights interpolated from the outline), or None (a single polygon face).

Curve Samples

Points taken along each spline segment, from 1 to 64. Raise it for smoother curves.

Flip

Reverses every generated face, turning the surface and its shell inside out.

Under Shell, the surface can get a thickness:

Shell

The distance from the base to the extruded top. Zero keeps a single surface.

Extrusion Direction

The direction of the shell, in the spline's local space.

Base Offset

Moves the base along the extrusion direction before the shell is extruded.

Add Top, Add Walls and Add Bottom

Which parts of the shell are built.

Under Materials, each part can get its own material:

Top Material

The material of the surface, or of the shell's top. Empty keeps the renderer's first material.

Wall Material and Bottom Material

The materials of the shell's walls and bottom. Empty uses the top material.

When all three are empty, the renderer's materials are left as they are and the whole surface uses the first one.

After creating¶

A new primitive keeps its parameters, so you can still change its size or number of segments in its Editable Primitive inspector. To edit its vertices, edges and faces, use Make Editable first. See Editable Meshes.