The Hard-Surface Toolkit: Loop Cuts, Bevel, Subdivision

• Scroll the mouse wheel before clicking to set how many loops you add.
• Left click once to accept the count, then slide the mouse to position the loop.
• Right click, or press Enter, leaves the loop perfectly centered.
• Typing a number places the loop at that fraction (0.5 is the middle), which is precise but relative.

One rule matters more than the rest: ==a loop cut travels across quads and stops at triangles or n-gons==. If a loop refuses to run where you expect, you have a non-quad face in the way.

Bevel: the jewelry edge

Ctrl+B on selected edges rounds them. While the bevel is active:

• Move the mouse to set width, or type a value such as 0.2 to set exactly 0.2 mm.
• Scroll the mouse wheel to change the number of segments. Two to three segments read as polished metal at jewelry scale; ten are wasted polygons.
• Press S to adjust the profile shape, which shifts the roundness toward a flatter or fuller curve.

For asymmetric edges, select only the edges you want rounded. Ctrl+Shift+B bevels vertices instead, which is useful for softening a corner.

Bevel weight: crisp on one side, soft on the other

Real settings often need a soft outer edge and a sharp inner seat. Select the soft edges in Edit Mode, open Object Data Properties, find Edge Data > Bevel Weight, and raise it. Then add a Bevel modifier and set Limit Method to Weight. Now the modifier rounds only the weighted edges, and you can retune the width later without touching the mesh.

Subdivision Surface: smoothing with control

The Subdivision Surface modifier splits every face and averages the result using the Catmull-Clark algorithm. Level 1 already doubles the density; level 2 is a good viewport default, and level 3 is usually enough for a final render.

Catmull-Clark pulls geometry inward, so a subdivided cube becomes a soft blob. Two tools hold the shape:

1. Support loops: extra loop cuts placed close to the edges you want to keep tight.
2. Creases: select an edge and press Shift+E, then drag, to pin it.

Subdivision also loves quads. Triangles and n-gons produce visible pinching, especially on curved ring surfaces.

[!WARNING] Modifier order matters. Bevel sits above Subdivision in the stack so the subdivided surface smooths the beveled edge rather than the raw corner.

flowchart LR
    A["🧱<br/>Blockout"] --> B["✂️<br/>Loop cuts"]
    B --> C["🪒<br/>Bevel 0.2 mm"]
    C --> D["🌊<br/>Subdivision"]
    D --> E["🔍<br/>Check silhouette"]

Tool	Shortcut	Mode
Loop Cut	Ctrl+R	Edit Mode
Bevel edges	Ctrl+B	Edit Mode
Bevel vertices	Ctrl+Shift+B	Edit Mode
Edge Slide	G G	Edit Mode
Edge Crease	Shift+E	Edit Mode

Worked Examples

Example 1: A flat plate with controlled edges

This is the warm-up shape you will reuse in the capstone blockout.

1. Add a Cube, then set its dimensions in the N panel to X 20 mm, Y 12 mm, Z 1.2 mm.
2. Enter Edit Mode, press `Ctrl+R`, scroll to 3 loops, left click, right click to center.
3. Slide the outer loops to about 1 mm from each long edge with `G G` and snapping on. These are support loops.
4. Select the four long edges around the top face, press `Ctrl+B`, type `0.2`, press Enter.
5. With the bevel still active, scroll to 2 segments.
6. Add a Subdivision Surface modifier, set viewport level to 2 and render level to 3.

Result: a plate with a soft, light-catching rim and flat faces that stay flat.

Example 2: Weighted edges on a stepped form

1. Select only the outer rim edges.
2. In Object Data Properties, set Bevel Weight to 1.0.
3. Add a Bevel modifier, Width 0.25 mm, Segments 3, Limit Method Weight.
4. Check that the inner step is still crisp. If it rounded too, you selected the wrong edges.

Example 3: Fixing a pinched curve

You bevel a band segment and the subdivision shows a dark crease. Cause: a triangle next to the bevel. Fix: select the triangle pair, press Alt+J to turn it into quads, then re-bevel.

Guided Practice

These exercises build pieces you will place into the capstone scene next lesson.

Exercise 1: The 0.2 mm edge Model a 15 mm x 5 mm x 1.5 mm bar with a 0.2 mm bevel, 3 segments, on the two long edges only. Render a close-up of one edge.

Click to reveal guidance

Use Ctrl+B, type 0.2, Enter, then scroll to 3 segments before confirming. If the highlight looks like a thin hard line, your bevel is too narrow for the render size. If it looks like a plastic tube, it is too wide. Compare against a real ring you own.

Exercise 2: Weighted soft edge Take the same bar and keep the short end edges perfectly crisp while the long edges stay soft.

Click to reveal guidance

Delete the edge bevel from the mesh, reassign Bevel Weight 1.0 to the long edges only, and add a Bevel modifier with Limit Method set to Weight. The short ends will stay sharp because their weight is zero.

Exercise 3: Support loop test Subdivide a plate with no support loops, then add loops 1 mm from every edge and subdivide again.

Click to reveal guidance

Without support loops the plate turns into a pillow. With loops 1 mm in, the faces stay flat and only the last millimeter curves. That is exactly how a polished flat band behaves.

Expert Corner

• Bevel width is a design decision, not a default. At jewelry scale, 0.05 to 0.3 mm covers most cases. Write the number you chose in your object notes so the whole set matches.
• Two or three segments, not ten. Extra segments cost render time and rarely change the silhouette.
• Subdivision does not fix bad topology. Quad-based, evenly spaced faces subdivide well; long thin triangles pinch.
• Check normals early. Select all, Shift+N in Edit Mode. Inverted normals make bevels render as dark slivers.
• Viewport level 2, render level 3 is a safe starting pair. Raise levels only if a close-up still shows faceting.
• Do not shade smooth to hide sharp geometry. Smooth shading on a raw 90 degree edge produces a smeared highlight that no amount of lighting fixes.

Summary and Next Steps

Loop cuts place control lines, bevels give metal its small polished radius, and subdivision turns a blocky model into a smooth one while support loops and weights protect the edges that must stay crisp.

Fill in these key facts from memory:

The shortcut for Loop Cut is {{c1::Ctrl+R}}, and for Bevel it is {{c2::Ctrl+B}}.
While a bevel is active, the mouse wheel changes the number of {{c3::segments}}.
Subdivision Surface uses the {{c4::Catmull-Clark}} algorithm and behaves best on {{c5::quads}}.
To round only selected edges with a modifier, set Limit Method to {{c6::Weight}}.

[
  { "front": "What does Ctrl+R do in Edit Mode?", "back": "Adds a loop cut ring of edges; scroll first to choose how many." },
  { "front": "After clicking to accept a loop cut count, how do you keep the loop centered?", "back": "Right click or press Enter to leave it at the midpoint." },
  { "front": "Where does a loop cut stop traveling?", "back": "At triangles or n-gons; it only crosses quad faces." },
  { "front": "How do you set an exact bevel width in millimeters?", "back": "Press Ctrl+B, type the value such as 0.2, then press Enter." },
  { "front": "How do you change bevel segments while the bevel is active?", "back": "Scroll the mouse wheel." },
  { "front": "Typical bevel width range for polished jewelry edges?", "back": "About 0.05 mm to 0.3 mm." },
  { "front": "Where do you set Bevel Weight on a mesh?", "back": "Object Data Properties, Edge Data, Bevel Weight, with edges selected." },
  { "front": "Which Bevel modifier setting makes it use only weighted edges?", "back": "Limit Method set to Weight." },
  { "front": "What algorithm does Subdivision Surface use?", "back": "Catmull-Clark." },
  { "front": "What are support loops?", "back": "Loop cuts placed close to an edge to hold the shape during subdivision." },
  { "front": "Which shortcut creases an edge?", "back": "Shift+E in Edit Mode, then drag." },
  { "front": "Correct modifier order for a jewelry piece?", "back": "Bevel above Subdivision, so the beveled edge gets smoothed." },
  { "front": "What causes subdivision pinching?", "back": "Triangles or n-gons; convert them to quads (Alt+J) and rebuild the bevel." }
]

Next up: Capstone Kickoff. You will receive the design brief and turn these tools into the first blockout of your piece, using loop cuts for proportions and a single test bevel to judge scale before any detail work begins.