【Blender】Modifier Fundamentals - Mirror and Subdivision Surface

Created: 2025-12-06

Detailed guide on the most frequently used modifiers in Blender: Mirror and Subdivision Surface

Overview

Modifiers are powerful features that non-destructively change an object's shape. You can apply various effects while preserving the original mesh. This article explains two essential modifiers beginners should learn first: Mirror and Subdivision Surface.

What are Modifiers?

Modifiers are like "filters" you can apply to objects.

Features:

  • Non-destructive: Changes appearance without altering original mesh data
  • Real-time preview: See results before applying
  • Stackable: Multiple modifiers can be layered
  • Removable anytime: Delete if no longer needed

Add modifiers from the Properties panel's "Modifiers" tab (wrench icon).

Mirror Modifier

An essential modifier for creating symmetrical objects.

Basic Usage

  1. Select the object
  2. Properties → Modifiers → "Add Modifier"
  3. Select "Mirror"

That's all it takes for the object to be duplicated symmetrically along the specified axis.

Key Settings

SettingDescription
AxisSelect mirror axis (X/Y/Z). Multiple selection possible
ClippingPrevents center vertices from crossing the axis
MergeAutomatically merges overlapping center vertices
Mirror ObjectUse another object as the mirror reference

Importance of Clipping

With "Clipping" enabled, vertices won't cross the center line when you move them in Edit Mode. This prevents gaps in symmetrical models.

Subdivision Surface

A modifier that converts low-polygon models into smooth curved surfaces.

Basic Usage

  1. Select an object (e.g., a cube)
  2. Properties → Modifiers → "Add Modifier"
  3. Select "Subdivision Surface"

The angular cube transforms into a rounded shape.

Key Settings

SettingDescription
ViewportPreview subdivision level during editing (1-2 recommended)
RenderSubdivision level at render time (2-3 recommended)
Optimal DisplayMakes wireframe display cleaner

Notes

  • Too high levels will slow down your PC
  • Keep viewport low (1-2), increase render level as needed

Modifier Stack Order

When using multiple modifiers, order matters.

Recommended order:

  1. Mirror (symmetry)
  2. Subdivision Surface (smoothing)

If reversed, the mirror seam won't smooth properly, causing unintended results.

Applying Modifiers

When you want to finalize a modifier's effect, "apply" it.

How to apply:

  1. Click "∨" at the top right of the modifier
  2. Select "Apply"

Once applied, it cannot be undone. Always save your file before applying.

Common Problems

Mirror Not Working Correctly

  • Cause: Object origin is offset
  • Solution: Ctrl + Shift + Alt + C → "Origin to Geometry"

Subdivision Creates Weird Shape

  • Cause: Mesh has duplicate vertices or internal faces
  • Solution: In Edit Mode, A (select all) → M → "Merge by Distance"

Summary

  • Modifiers: Non-destructively change mesh appearance
  • Mirror: Essential for symmetrical modeling. Enable Clipping
  • Subdivision Surface: Easily creates smooth curved surfaces
  • Stack Order: Maintain Mirror → Subdivision order

Mastering these two modifiers will significantly improve your modeling efficiency.