Rendering Attributes

RIB Attributes

Name	Type	Description
`interpolateboundary`	Detail, Primitive	This attribute will turn on the interpolate boundary flag for sub-division surfaces in the RIB stream and can be set to 1 or 0.
`ri_curvestep`	Detail	Determines the step value for curve primitives.
`ri_curvebasis`	Detail	Determines the basis used for cubic curve primitives.
`ri_curveinterpolation`	Detail	Determines the interpolation (linear or cubic) for curve primitives.
`ri_subdivscheme`	Detail	Determines the subdivision scheme to be used. Defaults to `catmull-clark`.
`creaseweight`	Primitive, Vertex	Defines the crease weight for sub-division surfaces.
`Pref`	Matrix primitive attribute for metaballs.	Determines the rest position for metaballs.

Mantra Attributes

Name Description

Name	Description
`orient`	Determines orientation of curve/point primitives. Curves and points will be oriented so that their normals point in the direction of the “orient” vector attribute.
`v`	Used for velocity motion blur computations.
`uv`	Default attribute for the -u option (may be overridden by command line option).
`vm_photon` `vm_surface` `vm_displace` `shop_vm_photon` `shop_vm_surface` `shop_vm_displace`	Shader overrides (per primitive).
`width` `pscale`	Used to determine width of curve/point primitives (see below).

orient

Determines orientation of curve/point primitives. Curves and points will be oriented so that their normals point in the direction of the “orient” vector attribute.

v

Used for velocity motion blur computations.

uv

Default attribute for the -u option (may be overridden by command line option).

vm_photon

vm_surface

vm_displace

shop_vm_photon

shop_vm_surface

shop_vm_displace

Shader overrides (per primitive).

width

pscale

Used to determine width of curve/point primitives (see below).

Note	The `scale` attribute is not used by mantra.

When determining the size of point primitives, the following checks are done (in order):

Point attribute width
Point attribute pscale
Detail attribute width
Detail attribute pscale

When determining the width of curve primitives, the following checks are done (in order):

Vertex attribute width
Point attribute width
Primitive attribute width
Detail attribute width
Point attribute pscale

The first attribute found will determine the size of the point/curve primitives.