Subdivision Surface Modifier

The Subdivision Surface modifier (frequently shorten to "Subdiv") is used to split the faces of a mesh into smaller faces, giving it a smooth appearance. It enables you lot to create complex smooth surfaces while modeling elementary, depression-vertex meshes. It avoids the demand to save and maintain huge amounts of information, and gives a polish "organic" look to the object.

As with whatever modifier, order of execution (position in the modifier stack) has an important bearing on the results.

Go on in mind that this is a different operation than its companion, Smooth Shading. You tin see the departure betwixt the two in the grid image beneath.

../../../_images/modeling_modifiers_generate_subdivision-surface_grid.png

Subdivision levels 0 to 3, without and with Smooth Shading.

Tip

The Subdivision Surface modifier does not allow yous to edit the new subdivided geometry without applying it, only the Multiresolution modifier does (in Sculpt Manner).

Options

../../../_images/modeling_modifiers_generate_subdivision-surface_panel.png

The Subdivision Surface modifier.

Catmull-Clark

Subdivides and smooths the surfaces to create a more than pleasant looking mesh. According to its Wikipedia page, the "arbitrary-looking formula was chosen past Catmull and Clark based on the aesthetic advent of the resulting surfaces rather than on a mathematical derivation."

Simple

Only subdivides the surfaces, this often does not provide any smoothing unless the surface is non-coplanar (the same as the Subdivide operator, in Edit Mode). To work around this behavior for non-coplanar geometry, triangulate to ensure all geometry is coplanar.

Elementary mode tin can be used, for example, to increase the base of operations mesh resolution when using displacement maps.

Levels Viewport, Render

The number of subdivision levels shown in the 3D Viewport or the last return.

Warning

Higher levels of subdivisions results in more than vertices, which ways higher memory consumption (both system RAM, and video memory for display). This tin cause Blender to hang or crash if not enough memory is bachelor.

Tip

The right combination of these settings will allow you lot to keep a fast and lightweight approximation of your model when interacting with information technology in the 3D Viewport, but utilise a higher quality version when rendering.

Be careful not to set the Viewport subdivisions higher than the Render subdivisions, this would mean that the quality in the 3D Viewport volition exist college than the rendered.

Optimal Display

When rendering the wireframe of this object, the wires of the new subdivided edges will be skipped (only displays the edges of the original geometry).

Advanced

Use Limit Surface

Places vertices at the surface that would be produced with infinite levels of subdivision (smoothest possible shape).

Quality

When Use Limit Surface is enabled this holding controls how precisely vertices are positioned on the limit surface (relatively to their theoretical position of an infinitely subdivided mesh). It can exist lowered to get a better performance.

Using college values does not necessarily mean existent comeback in quality, ideal results might be reached well before the maximum Quality value.

Note

This value can affect the accuracy of Edge Creases; using a higher Quality value will allow for a wider range of crease values to work accurately.

UV Smooth

Controls how subdivision smoothing is practical to UVs.

None

UVs remain unchanged.

Keep Corners

UV islands are smoothed, but their boundary remain unchanged.

Keep Corners, Junctions

UVs are smoothed, corners on discontinuous boundary and junctions of iii or more regions are kept sharp.

Keep Corners, Junctions, Concave

UVs are smoothed, corners on discontinuous boundary, junctions of three or more regions and darts and concave corners are kept abrupt.

Go along Boundaries

UVs are smoothed, boundaries are kept sharp.

All

UVs and their boundaries are smoothed.

Boundary Smooth

Controls how open boundaries (and corners) are smoothed.

All

Smoothen boundaries, including corners.

Proceed Corners

Smooth boundaries, only corners are kept sharp.

Utilise Creases

Use the Weighted Edge Creases values stored in edges to control how smooth they are fabricated.

Use Custom Normals

Interpolates existing Custom Separate Normals of the resulting mesh.

Keyboard Shortcuts

To chop-chop add a Subdivision Surface modifier to one or more objects, select the object(due south) and press Ctrl-one . That will add a Subdivision Surface modifier with Viewport subdivisions set to 1. Yous tin apply other numbers as well, such as Ctrl-2 , Ctrl-3 , etc, to add a modifier with that number of subdivisions. Calculation a Subdivision Surface modifier in this fashion volition not change the Render subdivisions.

If an object already has a Subdivision Surface modifier, doing this will simply change its subdivision level instead of adding some other modifier.

Command

Catmull-Clark subdivision rounds off edges, and often this is not what you want. At that place are several solutions that allow yous to control the subdivision.

Weighted Edge Creases

Weighted edge creases for subdivision surfaces allows y'all to alter the mode the Subdivision Surface modifier subdivides the geometry to requite the edges a smooth or sharp appearance.

../../../_images/modeling_modifiers_generate_subdivision-surface_withcrease.png

A subdivided cube with creased edges.

The crease weight of selected edges can exist inverse in the Transform panel, Sidebar of the 3D Viewport. The scale-like dedicated tool Shift-E tin can besides exist used to accommodate the pucker weight. A higher value makes the edge "stronger" and more than resistant to the smoothing result of subdivision surfaces.

Border Loops

../../../_images/modeling_modifiers_generate_subdivision-surface_cube-with-edge-loops.png

Subdivision Level 2 cube, the same with an extra Edge Loop, and the same with half-dozen actress Edge Loops.

The Subdivision Surface modifier demonstrates why skilful, clean topology is so important. As you can come across in the figure, information technology has a drastic effect on a default cube. Until you lot add in additional loops (with e.yard. Loop Cutting and Slide), the shape is almost unrecognizable as a cube.

A mesh with deliberate topology has practiced placement of edge loops, which let the placement of more than loops (or their removal) to control the sharpness/smoothness of the resultant mesh.

Known Limitations

Not-Face-to-face Normals

Blender'southward subdivision system produces nice smooth subdivided meshes, but any subdivided face (that is, whatsoever minor face created by the algorithm from a single face of the original mesh), shares the overall normal orientation of that original face up.

../../../_images/modeling_modifiers_generate_subdivision-surface_normal-orientation-1.png

Comparing of practiced normals and bad normals.
../../../_images/modeling_modifiers_generate_subdivision-surface_normal-orientation-2.png

Side view of image on the left.

Precipitous normal changes can produce ugly blackness gouges even though these flipped normals are not an issue for the shape itself.

A quick mode to gear up this is to apply Blender's Recalculate Normals functioning in Edit Fashion.

If you yet have some ugly black gouges you will have to manually flip the normals.