# Hard surface modeling - How to model engraved lines?

I'm trying to model a sci-fi helmet, in particular those hollow lines that I marked in red color:

So far I have tried:

1. Boolean difference using super thin cubes
2. Modeling each part separately

Both methods are time consuming and I imagine there are better options. What kind of tools or methods you would recommend to do this sort of modeling?

• This is a quite flexible option. – Robin Betts Mar 6 at 17:55

# Method 1 - Split Vertices

Such engraved lines can be created by splitting vertices and using the Solidify and Bevel modifier. The vertices of edges can be split manually in Edit mode (V + Enter) or mark them as Sharp and use the Split Edge modifier.

The vertices around the circle are split manually, the others are marked as sharp.

Modifier stack is:

• Subdivision Surface: level: 2
• EdgeSplit: [_] Edge Angle (unchecked), [X] Sharp Edges
• Solidify: default values
• Bevel: Segments: 2, Limited Method: Angle, Angle: 30° (default)

Video: Modeling Techniques Hardsurface in Blender combined - Pedro Augusto (The part about panels comes towards the end of the video.)

# Method 2 - Boolean Modifier

Alternatively, you can copy the model parts, use the Boolean modifier (operation: Difference) to cut it out, and another Boolean modifier (operation: Intersection) on the copy to get the cut-out part. This way you have a deep cut between the parts. Finally, add a Bevel modifier to each part. And tick the Shading[X] Harden Normals option in the Bevel modifier to fix the shading.
Note: This requires in the Object Data Properties the Normals[X] Auto Smooth setting to be activated.

The Bool Cutter object on the screenshot is 2 cubes join together. One cuts the sphere at the top, the other one cuts it at the bottom. The sphere is actually 2 spheres (one is the middle part, the other one is the top and bottom parts).

# Method 3 - Mask Modifier

A flexible method that uses the existing edge loops of the mesh and Bevel and Mask modifiers to create the support loops and the gap. It's described here by Robin Betts: What is the best way to model the intersection of multiple hard-surface pieces?

• Amazing, exactly what I was looking for – CONQUERER HOON Mar 7 at 7:19
• Thank you so much for a detailed answer! – CONQUERER HOON Mar 7 at 7:19