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To render the curve, we need to add at least a width attribute, curve interpolation and basis. 

Add Width Attribute

• Add a width attribute with Attribute Create.  Set a width value at the bottom, e.g. 0.01.

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• Map the width attribute to RenderMan attribute with Attribute Rename.

• Connect the nodes.

Add Curve Interpolation and Basis

In your ROP, select Edit Parameter Interface and add ri_curveinterpolation and ri_curvebasis.  Set the interpolation and basis accordingly.

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