Reference

Guided tour

Every module, in order, one short exercise each. About an hour end to end. By the finish you will have touched everything Rhea does and know which parts you actually want.

1 · Library

1. 01

   Add a base

   Library → Bases → Blob. It appears at the 3D cursor.

2. 02

   Change its parameters

   Raise Resolution. The mesh rebuilds. Note that this regenerates rather than deforms — any edits you had made would be gone.

3. 03

   Add a component

   Library → Components → Gear, and change Teeth. Every one of the thirty-two shapes has controls like these.

2 · Effects

1. 01

   Apply one

   Select the Blob. Effects → Organic shell → Apply recipe. You get a honeycomb whose struts thicken where the surface curves.

2. 02

   Adjust it

   Drag Thickness and Variation. Change Seed a few times.

3. 03

   Stack a second

   Add effect → Displace. It runs on the shell, not on the Blob. Move it above the first and watch the result change completely.

4. 04

   Revert

   Your original Blob comes back untouched. Nothing was destructive.

3 · Live tessellation

1. 01

   Set it up

   A Torus as the base and a Fin as the component. Select the Torus, then Add effect → Tessellate, and assign the Fin.

2. 02

   Find the shape

   Raise Height. Then Tilt to about 35° — the fins rake. Then Twist, and they wind.

3. 03

   Try taper

   Raise Taper past 2 with a high Height. Blades become spines. This is the control that turns any component into something hair-like.

4. 04

   Break the regularity

   Wobble around 20°, Scatter around 0.5, Coverage down to 0.6.

4 · The Tessellate module

1. 01

   Constant mode

   Grid base, Hex tile component, one slot. Press Tessellate. Read the result line: vertices, faces, ngons, time.

2. 02

   Frame mode

   Switch to Frame — no component needed. Adjust frame thickness and depth. This is a lattice with no modelling at all.

3. 03

   Patch mode

   Grid base, Weave component, Patch mode. The strands run continuously across face boundaries rather than restarting at each one. Compare against Constant to see the difference.

4. 04

   Output quality

   Turn on strict topology and re-run. The result line should read 0 ngons.

5 · Conway operators

1. 01

   Make a football

   Seed Icosahedron, click truncate in the picker. That is tI, and it is a football.

2. 02

   Turn on shading and canonicalize

   Enable angle-based shade smooth and canonicalize. The difference is dramatic, and without them every chain looks the same.

3. 03

   Keep clicking

   Add kis, then ambo, then gyro. Watch the face count in the panel climb.

4. 04

   Try a preset

   Load Geodesic sphere or Rhombicosidodecahedron from the preset dropdown.

6 · Topology tools

1. 01

   Dual mesh on an open surface

   Add a Grid. Run Dual mesh three times, once per boundary mode — Ignore, Close, Extend. The edges differ substantially; Extend is usually what you want.

2. 02

   Lloyd relax

   Take a lumpy mesh and relax it with preserve shape on. Then turn it off and run again — the mesh smooths toward a ball.

3. 03

   Adaptive subdivide

   Generate a curvature field first, then subdivide with it as the attribute. Density follows curvature, with no cracks at the transitions.

7 · Fields

1. 01

   Turn on the heatmap first

   Overlays → Field heatmap, attribute rhea_field. Now you can see what you are doing.

2. 02

   Generate curvature

   On a Blob. Watch the heatmap. Then adjust contrast, blur and quantise and watch each one change it.

3. 03

   Try a formula

   sin(x * 4) * 0.5 + 0.5 gives waves along X. Then smoothstep(0.2, 0.8, nz) masks upward-facing normals.

4. 04

   Drive something with it

   Add a Tessellate effect and put your attribute name in its Attribute box. Raise Variation. The copies now respond to the field.

8 · Differential growth

1. 01

   Planar line

   Default settings, press Run. Watch the circle ruffle. Cancel with Esc at any point.

2. 02

   Change the fold scale

   Raise the repulsion radius substantially and run again. Fewer, broader folds. Lower it: dense fine ruffling.

3. 03

   Break it deliberately

   Raise step size to its maximum and run. It tears itself apart — that is what an unstable explicit integration looks like, and it is worth seeing once so you recognise it later.

9 · Reaction-diffusion

1. 01

   Run coral

   On a reasonably dense Blob. Preset Coral, a hundred steps. Watch the pattern develop in the viewport.

2. 02

   Compare presets

   Run Maze and Spots from the same starting mesh. They should look nothing alike.

3. 03

   Feed it forward

   Write to a float attribute, then use it to drive tessellation thickness. Scales grow tall along the branches. This is the single most effective combination in the toolkit.

10 · Surface Voronoi

1. 01

   Cell faces

   Sixty cells, three relax passes, moderate inset. Separate plates across the surface.

2. 02

   Cell borders

   Switch output to borders and give them a width. Set the width to zero and note that they vanish from render — edges carry no faces.

3. 03

   Drive the density

   Put a curvature field in the Density box. Cells crowd where the form bends.

11 · Form finding

1. 01

   Minimal surface

   On a Tube or a Catenoid, boundary pinned. Run and watch the residual fall.

2. 02

   Hanging chain

   Same mesh, hanging chain preset. Then flip the result vertically — you now have a compression shell.

3. 03

   Break it deliberately

   Turn off pin boundary and run. It collapses toward a point. That is what an unconstrained solve does, and it is the most common first-attempt failure.

12 · Panelize and fabricate

1. 01

   Analyse before you optimise

   On a Saddle, run Analyse planarity with the overlay on. Red where the double curvature is strongest. Then do the same on a Vault — it is already flat everywhere, because single curvature is.

2. 02

   Planarise

   Run it on the Saddle and analyse again. Note how much shape changed to get there.

3. 03

   Waffle

   Six ribs each way, material thickness set to something real. Then export SVG and open the file — the parts are nested and labelled.

13 · Overlays

• Boundary edges on an open mesh, then on a closed one. The closed one should show nothing.
• Face orientation on a clean grid, then on an imported or heavily edited mesh. The difference in arrow consistency is the thing to learn to see.
• Field heatmap — you have already used this and it is the one you will keep.

Where to go next

• Best practices — the things that stop results going subtly wrong.
• Use cases — complete routes through the toolkit for specific kinds of work.
• Performance — before you scale anything up.