Subdiv Surface Modeling Tutorial

Basic Workflow

A subdiv modeling is a method of representing a smooth surface via the specification of a coarser piecewise linear polygon mesh. The smooth surface can be calculated from the coarse mesh as the limit of an iterative process of subdividing each polygonal face into smaller faces that better approximate the smooth surface.
• Rough Polygon Modeling > Subdiv Surface Modeling

Surfaces

Subdiv Commands

Subdiv commands will be under the Surface Context. Though you will find yourself going between Polygon commands as well as Subdiv Surface commands.

Convert Polygon to Subdiv

Converting Polygon to Subdiv

Best practices: Keeping Subdiv modeling in mind, keep your Polygon model as rough as possible. Sculpting the general construct. Then refining in Subdiv mode is the idea.
• Select Polygon
• Modify > Convert > Polygons to Subdiv

Polygon Mode

Shifting between Polygon and Subdiv Mode

Since Subdiv modeling is built on the foundation of Polygon modeling, you will often go between the two modes. As the naming suggest 'Subdiv', it is a method to organize the geometry to keep it efficient in how it hands different resolution on the same surface.
• Right-click and select Polygon or Standard

Creased edge

Adding definition to the Subdiv

• Select an edge
• Choose type of definition
• Full Crease Edge/Vertex
• Partial Crease Edge/Vertex
• Uncrease Edge/Vertex

Display Level

Component Display Level

• Finer
• Coarser
• Base

Refine Selected

Adding Detail

In order to add resolution to your model, instead of adding division as you would do in Polygon modeling, you will 'Refine Selected' a region you would like to add detail.
• Select the component you would like to refine (vertex, edge, face)
• Subdiv Surfaces > Refine Selected Components
• or right-click > Refine Selected

Move Tool Options

Moving component in its normal direction

Double-click on the move tool
• Select in the Move Settings 'Normal'

Sculpt Geometry Tool

Convert Selection

• Convert Selection to Faces
• Convert Selection to Edges
• Convert Selection to Vertices
• Convert Selection to UVs
• Refine Selected Comnponents
• Select Coarser Components
• Expand Selected Components

conversion settings

Conversion/Exporting for 3D printing

Converting your subdiv model to a polygon.
• Select your subdiv model
• Modify > Convert > Subdiv to Polygons
• You should have adaptive checked and play with the 'Divisions per face' slider to see if the resolution is high enough for your model

Plug-in Manager

Make sure your OBJexporter plug-in is on.
• Window > Settings/Preferences > Plug-in Manager
• check on the Loaded check box for objExport.mll

Exporting

• Select your converted polygon model
• File > Export Selected...

Out come difference

Subdivison Topology

The polygon topology effects the subdivision model in how it will smooth. Left to Right, below is the genome of each vase.
• Left Model
• start from polygon plane (1x1 divison)
• extrude face, local translateZ 1
• extrude top face, local scaleX, scaleY, scaleZ 0.5
• extrude the internal face, local translateZ 0.5
• delete the extruded face at top
• Middle Model
• start from polygon plane (1x1 divison)
• extrude face, local translateZ 1
• add division, quad division
• extrude the vertex in the center
• delete the extruded vertex
• extrude the internal face, local translateZ 0.5
• delete the extruded face at top
• Right Model
• start from polygon plane (1x1 divison)
• extrude face, local translateZ 1
• add division, linear mode, 3 division in both U and V
• extrude the face in the center, local translateZ 0.5
• delete the extruded face at top


Note the Left Model is composed of all quad faces. Middle Model have 5 sided faces. Right Model have 6 sided faces, also T joints.