Creator Guide

Advanced Shapes: Parametric Controls

Every basic shape is also a starting point. With parametric controls, you can cut, hollow, twist, taper, and shear your prims into something entirely different -- and change your mind at any time.

The Build Panel's Shape tab gives you basic primitives -- boxes, spheres, cylinders, and more. But the real creative power comes from the parametric deformation controls: a set of sliders that reshape any prim without destroying or replacing it. Think of them as non-destructive sculpting tools. A box becomes a door frame. A cylinder becomes a spiral staircase. A torus becomes an arch.

The key insight: every change is reversible. Slide a parameter to zero and you are back to the original shape. There is no "undo history" to worry about -- the shape is always generated fresh from the current slider values.

The Build panel's Shape tab with a box selected. The expanded SHAPE accordion shows three card sections. CUTS contains Path Cut and Slice, each a dual-handle slider reading 0.00 to 1.00. HOLLOW contains an Amount slider reading 0% and a Shape selector with square, circle, and triangle icon buttons, square highlighted. DEFORMATION contains a Twist slider with both handles centered reading 0 degrees at each end, and two square drag-pads labeled Taper and Shear, each with a centered green dot and readouts X:0.00 Y:0.00. A Reset button sits at the bottom of the section.
Figure 1. The SHAPE accordion on a selected box: Cuts (Path Cut and Slice), Hollow (amount plus hole-shape selector), and Deformation (Twist, Taper, Shear). Every slider starts at its neutral value -- slide anything back to zero and the original shape returns.

How It Works

Every prim is built from two things: a profile (the cross-section shape) and a path (the direction the profile is extruded along). A box has a square profile pushed along a straight line. A torus has a circular profile swept around a ring. The parametric controls let you modify both the profile and the path independently.

Profile controls change the cross-section: cut a wedge out of it, punch a hole through its center, or change the shape of that hole. Path controls change how the profile is extruded: twist it, taper it, lean it sideways, or remove a section of the extrusion entirely.

Profile Controls: Changing the Cross-Section

These controls modify the shape you see if you were to slice the prim in half and look at it head-on.

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Path Cut (Profile on the torus family)

Removes a pie-slice wedge from the cross-section. You set a begin and end point, and everything between them is cut away -- like slicing a pizza and removing a piece. On a cylinder, this gives you a Pac-Man shape. On a sphere, it opens up a bowl or dome.

The panel labels this control Path Cut on boxes and cylinders, and Profile on torus, tube, and ring -- same idea, different name per family.

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Hollow

Punches a hole straight through the center of the prim, from top to bottom. The hollow percentage controls how big the hole is -- 0% is solid, 95% leaves paper-thin walls. This is how you make pipes, picture frames, tunnels, and hollow towers.

The hole shape does not have to match the prim shape. The Shape selector always offers three profiles, and the choices adapt to the prim you have selected:

  • Same -- The default. The hole matches the prim's own cross-section: a square hole through a box, a round hole through a cylinder or torus.
  • Circle or Square -- The alternate profile: a box offers Circle (a round bore through a cube), while cylinders and the torus family offer Square.
  • Triangle -- Available on every shape. Unusual but useful for decorative openings and geometric patterns.
A white square column viewed from above at a three-quarter angle. A circular hole is bored vertically through the column: the round opening is visible on the white top face and the shaded cylindrical interior wall descends into the shape.
Figure 2. A Circle hollow at 70% punches a perfectly round bore through a square box -- the hole shape is independent of the prim shape. This exact combination (a round hole in a cube) is a showcase of the parametric mesher.

Path Controls: Changing the Extrusion

These controls modify how the cross-section is pushed through space. They turn simple shapes into complex architectural and decorative elements.

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Slice (Path on the torus family)

Removes a section of the extrusion itself. On a box or cylinder the panel calls this Slice: it cuts horizontally -- you might cut away the top third to make a low wall. On the torus family the same knob is labeled Path: it removes an arc segment, turning a full ring into a C-shape or a half-circle. Set the begin and end points to control which portion is kept.

↻

Twist

Rotates the cross-section progressively along the extrusion path. A box with 90 degrees of twist turns into a gentle spiral. Crank it to 360 degrees and you get a full helical revolution. You can set different twist values at the begin and end of the path, so the twist can accelerate, reverse, or stay constant.

Twist goes up to 360 degrees in either direction -- plenty for spiral staircases, twisted columns, candy cane stripes, and decorative railings.

Twist exists on straight-path shapes only (box, cylinder, prism). The torus family has no Twist control -- its deformation card offers Skew, Revolutions, Radius Delta, and Hole Size instead (see Ring and Torus Controls below).

A plain white rectangular column standing on a gray platform against a blue sky, viewed from a three-quarter angle. The same column with 360 degrees of twist applied: the square cross-section spirals a full revolution from bottom to top, producing helical fluted edges like a twisted ribbon, same camera angle and lighting as the untwisted shot.
Figure 3. One parameter, one dramatic difference: the same tall box at Twist 0° (left) and 360° (right). The cross-section rotates a full turn between bottom and top, turning a plain column into a helix -- drag the slider back to 0° and the box returns.
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Taper

Shrinks or grows the cross-section along the path. A box tapered on both axes becomes a pyramid. A cylinder tapered on one axis becomes a wedge or a funnel. Taper works independently on X and Y, so you can create asymmetric shapes -- narrow on one axis but full-width on the other.

Negative taper values flip the effect, making the top larger than the bottom. This is useful for creating flared bases and trumpet shapes.

A white cone standing on a gray floor, made from a tapered cylinder. The tip is truncated and open: a small circular opening at the top shows a bright thin rim where the hollow interior meets the tapered wall.
Figure 4. A funnel from two sliders: a cylinder with Hollow at 90% and Taper at 0.8 on both axes. The walls stay paper-thin while the cross-section shrinks toward the top, leaving an open spout.
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Shear

Offsets the top of the prim sideways relative to the bottom, without changing the shape of either end. A box with shear becomes a parallelogram. Shear works on X and Y independently, so you can lean the top forward, sideways, or diagonally. This is how you make leaning towers, slanted roofs, and italic-style text blocks.

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Skew

Leans the entire extrusion path sideways. Where shear offsets just the top, skew bends the whole path into a curve, tilting the ring into an elliptical orbit. Skew appears on the torus family's deformation card (torus, tube, ring) with a range of -0.95 to 0.95 -- straight-path shapes do not have it.

Ring and Torus Controls

Torus, tube, and ring shapes have their own deformation set because their path wraps around in a circle rather than going in a straight line. Their deformation card offers Skew, Revolutions, Radius Delta, and Hole Size X/Y, plus the same Taper and Shear drag-pads as the straight-path shapes. (There is no Twist control on the torus family.)

Control Range What It Does
Skew -0.95 to 0.95 Leans the ring's path sideways, tilting it toward an elliptical orbit.
Revolutions 1 to 4 How many times the profile wraps around. At 1, you get a simple ring. At 2 or more, the ring spirals into a coil -- like a spring or a slinky.
Radius Delta -1 to 1 Makes the ring spiral inward or outward as it revolves. Combined with multiple revolutions, this creates spiral ramps and nautilus shapes.
Hole Size X 0.05 to 1 (default 1) Adjusts the ring's proportions along one axis of the cross-section.
Hole Size Y 0.05 to 1 (default 0.25) Adjusts the ring's proportions along the other axis.
Taper / Shear XY pads The same drag-pads as on straight-path shapes, applied around the ring.

Heads-up: the Hole Size controls currently behave unpredictably -- raising Hole Size Y can grow the tube inward and close the central hole entirely, and lowering Hole Size X can flatten the whole ring rather than narrowing the hole. This is a known issue under investigation. Until it settles, treat these two sliders as experimental and lean on the Path cut, scale, and the other controls for predictable results.

A thick white half-torus standing like an arch on a gray platform, viewed from a three-quarter angle. The lower half of the ring has been cut away: two flat oval cut surfaces face downward as legs, and a dark tunnel opening passes beneath the remaining arc.
Figure 5. The fastest arch in the toolset: a torus with Path cut to 0.25–0.75 keeps only the top half of the ring. The two flat cut faces become the arch's feet. Scale it up to fit a doorway.

Practical Examples

Here are common things builders make with parametric controls, along with the settings that produce them.

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Door Frame

Start with a Box. Set Hollow to around 80% and leave the hollow shape on Same (a square hole, matching the box). You now have a rectangular frame. Scale it to the size of a doorway and position it in your wall. The hollow creates the opening; the remaining material is the frame.

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Spiral Staircase

Start with a Box. Set Twist to 360 degrees (or more for tighter spirals). Make the box tall and thin -- the twist wraps it around itself like a ribbon. Adjust the width to control tread depth and the twist amount to control how many steps fit in one revolution.

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Arch

Start with a Torus. Set Path (the torus's second cut slider) to keep only the top half (begin at 0.25, end at 0.75 -- experiment to taste). You now have a half-ring arch: the two flat cut faces become its feet. Scale it to fit over a doorway or bridge. The Path cut alone gets you there -- hold off on the Hole Size sliders for now (see the heads-up above).

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Funnel

Start with a Cylinder. Set Hollow to about 90% (for thin walls) and Taper both X and Y to around 0.5. The cylinder narrows toward the top while staying hollow inside -- a funnel. Reduce the taper to make it more gradual, or increase it for a steep cone.

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Pyramid

Start with a Box. Set Taper on both X and Y to 1.0. The box narrows to a point at the top -- a clean four-sided pyramid. Use lower taper values for a truncated pyramid (flat top), or taper only one axis for a wedge-shaped roof.

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Pipe Bend

Start with a Torus. Set Path to keep a quarter-arc (begin 0.0, end 0.25). Set a large Hollow -- the default Same profile is already round on a torus. You have a 90-degree pipe elbow. Adjust the Path range for different bend angles.

Base Shapes That Support These Controls

Parametric controls work on all of the standard primitive shapes. The effect of each control varies slightly depending on whether the shape uses a straight extrusion path (like a box) or a circular revolution path (like a torus).

■ Box
● Sphere
◇ Cylinder
▲ Prism
○ Torus
□ Tube
▵ Ring
The Build panel CREATE palette with four shape cards: Box, Sphere, Cylinder, Torus. Below the Torus card an opened dropdown shows two additional cards, Tube and Ring, each with a ring-style icon. Behind the dropdown the TRANSFORM section of a selected torus is partially visible.
Figure 6. Torus, Tube, and Ring live under one palette card -- click the small arrow in the Torus card's corner to pick a variant. (Box hides Prism under the same corner arrow.)

Straight-path shapes (box, cylinder, prism) respond to twist, taper, and shear in straightforward ways -- the deformation happens along the height of the shape. Revolution-path shapes (torus, tube, ring) trade Twist for the ring-specific set -- skew, revolutions, radius delta, and hole size -- controls that only make sense when the path wraps around in a circle.

Quick Reference

Parameter What It Does Good For
Path Cut (Profile on torus) Removes a wedge from the cross-section Pac-Man shapes, domes, open bowls
Hollow Punches a hole through the center (up to 95%) Frames, pipes, towers, tunnels
Slice (Path on torus) Removes a section of the extrusion Arches, half-rings, partial walls
Twist Rotates the shape along its length (straight-path shapes only) Spiral stairs, twisted columns, ribbons
Taper Narrows or widens toward one end Pyramids, funnels, wedge roofs
Shear Offsets the top sideways Leaning shapes, slanted roofs, parallelograms
Skew Leans the whole extrusion path (torus family only) Tilted rings, elliptical orbits

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