How does open inventor / coin3d enable two-sided rendering like OpenGL？

Question

Coin3D uses single-sided rendering by default like the image below：

_{(source: gitee.com)}

score 3 · Accepted Answer · answered Dec 17 '20 at 14:23

3

SoShapeHints is the answer, but this summary may be clearer:

Two-sided lighting and backface culling are disabled by default.
Two-sided lighting: enabled if not solid and ordered vertices.
Set vertexOrdering to COUNTERCLOCKWISE (usually) or CLOCKWISE.
Backface culling: enabled if solid and ordered vertices.
Set shapeType to SOLID.

answered Dec 17 '20 at 14:23

mike

186
3

I got it, just need to set the vertexOrdering. – 风何之 Dec 18 '20 at 05:17

score 0 · Answer 2 · answered Dec 17 '20 at 12:48

You should add a SoShapeHints node before the geometry in the scenegraph either with shapeType set to UNKNOWN_SHAPE_TYPE if you already set the vertexOrdering to CLOCKWISE or COUNTERCLOCKWISE, or with the vertexOrdering set to UNKNOWN_ORDERING for any shape type, e.g.

ShapeHints {
    vertexOrdering UNKNOWN_ORDERING
    shapeType UNKNOWN_SHAPE_TYPE
}

For further explanation see the SoShapeHints documentation of Coin3D

How does open inventor / coin3d enable two-sided rendering like OpenGL？

2 Answers2