Subdivision Surface Method (OpenSubdiv)
Shade3D supports Pixar's OpenSubdiv, an open source subdivision surface tool.
Based on the Catmull-Clark method, a varying level of sharpness is applied to each edge, resulting in a complex shape with some sharper edges rather than a shape with uniformly rounded edges.
The valid range of parameters is compatible with most 3D software.
| Basic | Standard | Professional |
|---|---|---|
| O | O | O |
Usage
Select a polygon mesh and then apply the OpenSubdiv settings.
- Select Tools > Modify Mesh > Subdivision Surface > OpenSubdiv.
- In the Toolbox, select Modify > Mesh > Subdivision Surface > OpenSubdiv.
- From the Object Info Window, in the Subdivision Surface group select OpenSubdiv from the Method pop-up menu.
Before applying OpenSubdiv
After applying OpenSubdiv
After applying OpenSubdiv with sharpness applied to individual edges
Edge Sharpness Tool Parameters
To apply varying levels of sharpness to the edges, open the Edge Sharpness Tool Parameters.
- Select Tools > Modify Mesh > Subdivision Surface > Edge Sharpness.
- In the Toolbox, select Modify > Mesh > Subdivision Surface > Edge Sharpness.
- Mode Buttons
- In Edit mode, dragging in the Figure Window will change the sharpness value.
- In Select mode, edges in the Figure Window can be selected.
- Sharpness
- Sets the sharpness value.
Before applying sharpness
Sharpness of 2.0 applied (Surface Subdivision: Very Fine)
Sharpness of 4.0 applied (Surface Subdivision: Very Fine)
Depending on the level of sharpness, the color of the edge will change gradually from yellow to red.
The edges to which sharpness is applied differ depending on the polygon selection mode.
- Vertex Mode: Sharpness is applied to edges composed of two selected vertices.
- Edge Mode: Sharpness is applied to selected edges
- Face Mode: Sharpness is applied to the edges of selected faces.
Sharpness Changes Based on Level of Subdivision
The OpenSubdiv specification allows for values between 0.0 and 10.0, but the degree of sharpness applied in Shade3D is determined by the Surface Subdivision settings specified in the Rendering Settings or by the special characters < or > added to the shape name in the Browser.The upper limit of the noticable level of sharpness is 2 for Regular subdivision level, 3 for Fine, and 4 for Very Fine. The maximum value of sharpness for any level of subdivision is 10.0.
Surface Subdivision: Regular (maximum sharpness of 2)
Surface Subdivision: Fine (maximum sharpness of 3)
Surface Subdivision: Very Fine (maximum sharpness of 4)
Note When no sharpness is applied, results are identical to the Catmull-Clark method.
When the level of surface subdivision has been set in the Rendering Settings (on the Basic tab), the difference can be seen only in the rendered image.
When using the < or > characters in the shape or part name, the difference can also be seen in the Figure Window.
OpenSubdiv Settings in the Object Info Window
Other settings can be applied in the Object Info Window.
- Boundary Rule
- When set to Edge and Corner, the results will be the same as Catmull-Clark.
- When set to Edge Only, rounding is also applied to the corners of border edges.
- Smooth Triangles
- When selected, more smoothing will be applied to triangles.
- When unselected, the results will be the same as for Catmull-Clark.
Note When OpenSubdiv is selected, the weight of Smooth Triangles is fixed at 1.0.