Render: dress the challenge coin in materials

What the Render page looks like

Render keeps the completed 3D challenge coin in the center, the material library on the right, and selection tools on the left. Every assignment updates live, so you can judge the finish on the actual geometry rather than on a swatch alone.

Start under a neutral environment and a readable camera angle. Metals respond strongly to surroundings; if the lighting is extreme, it becomes difficult to tell whether a result is a material choice or only a reflection.

Explore freely, but establish the three base material regions before painting individual accents. A controlled baseline makes later refinements easy to compare and undo.

The three fixed parts

A challenge coin has three base material areas: front, back, and side (the edge). These are the foundational assignments that define the body before any local enamel or motif-specific material is added.

Click Front, then choose a material ball; repeat for Back and Side. Brass on the faces with a darker bronze or nickel edge is a useful starting comparison, but the most important choice is contrast: the edge should frame the face rather than disappear into it.

For a consistent physical finish, keep front and back related unless the design deliberately calls for contrast. Extreme differences can make a model feel like separate parts rather than one minted object.

The material library

Materials are grouped the obvious way: Metals (brass, bronze, silver, nickel…), Enamels for color, Plastics for proofs.

If you know the name, the search box finds it faster than scrolling.

Fine-tuning a material

Select a material and open Properties to adjust its physical response. Metalness controls whether it behaves like a conductor; roughness controls the spread of reflections. In practice, roughness is the faster control for making a surface read as polished, satin, bead-blasted, or worn.

Lower roughness produces tighter highlights and stronger reflections; higher roughness spreads highlights and reads more matte. Adjust in small increments, then rotate the coin under the same light. A material cannot be judged from one static highlight alone.

Avoid using very dark base color to simulate depth. Let geometry and lighting create depth; use color primarily to communicate the intended metal or enamel finish.

Coloring one motif with the wand

Want just the flame in red? Click it with the magic wand, adjust tolerance until the outline hugs the shape, then click Add at the bottom to make a new material slot for the selection.

Pick a red enamel ball and the color lands only inside the selection — nothing else changes.

Brushing a selection

When the boundary you want is not a color boundary, the wand struggles. Switch to Brush and paint the area by hand.

Overpainted? Subtract mode erases. Missed a spot? Add mode fills it back in.

Feathering and masks

The transition slider controls where two materials meet: zero is a crisp edge, bigger numbers blur it gently. Flat color fills like crisp edges; metal-on-metal likes a little feather.

Tick Show Mask and every material region is tinted its own color — the fastest way to spot a spot you missed.

Common questions

The wand grabbed half the challenge coin? Lower the tolerance, or tick Contiguous. Two materials look identical? Turn the coin toward the light and watch the highlights — they usually differ in roughness.

Mess up a selection? Clear Selection and start fresh — selections are cheap.