RdlMeshGeometry

Overview

RdlMeshGeometry generates either a polygonal or subdivision mesh defined soley by the node’s parameters.

The example below generates a single quad polygon.

RdlMeshGeometry("shape_basic") {
    ["vertex_list"] = { Vec3(0, 0, 0),
                        Vec3(0, 1, 0),
                        Vec3(1, 1, 0),
                        Vec3(1, 0, 0) },
    ["vertices_by_index"] = { 0, 1, 2, 3},
    ["face vertex count"] = { 4 },
}

Advanced subdivision mesh features such as creasing are also supported. The example below generates a mesh with creases.

RdlMeshGeometry("shape_creases") {
    ["node xform"] = translate(-4, -2, 0),
    ["vertex list"] = { Vec3(0, 0, 0), Vec3(0, 0, -1), Vec3(0, 0, -2),
                        Vec3(1, 2, 0), Vec3(1, 3, -1), Vec3(1, 4, -2),
                        Vec3(2, 0, 0), Vec3(2, 0, -1), Vec3(2, 0, -2),
                        Vec3(3, 2, 0), Vec3(3, 3, -1), Vec3(3, 4, -2),
                        Vec3(4, 0, 0), Vec3(4, 0, -1), Vec3(4, 0, -2),
                        Vec3(5, 2, 0), Vec3(5, 3, -1), Vec3(5, 4, -2),
                        Vec3(6, 0, 0), Vec3(6, 0, -1), Vec3(6, 0, -2),
                        Vec3(7, 2, 0), Vec3(7, 3, -1), Vec3(7, 4, -2),
                        Vec3(8, 0, 0), Vec3(8, 0, -1), Vec3(8, 0, -2) },
    ["vertices by index"] = { 0,  3,  4,  1,   1,  4,  5,  2,
                              3,  6,  7,  4,   4,  7,  8,  5,
                              6,  9, 10,  7,   7, 10, 11,  8,
                              9, 12, 13, 10,  10, 13, 14, 11,
                             12, 15, 16, 13,  13, 16, 17, 14,
                             15, 18, 19, 16,  16, 19, 20, 17,
                             18, 21, 22, 19,  19, 22, 23, 20,
                             21, 24, 25, 22,  22, 25, 26, 23},
    ["face vertex count"] = {4,4, 4,4, 4,4, 4,4, 4,4, 4,4, 4,4, 4,4},
    ["subd crease indices"]     = { 3, 4,  4, 5,    9,10, 10,11,
                                   15,16, 16,17,   21,22, 22,23},
    ["subd crease sharpnesses"] = { 0.0,   0.0,     1.5,   1.5,
                                    3.0,   3.0,    10.0,  10.0},
    ["is subd"] = true,
    ["subd scheme"] = "catclark",
    ["subd resolution"] = 20
}

The above code generates this creased mesh:

Attribute Reference

Geometry attributes

reverse_normals

Bool
default: False

enable to reverse the normals in the geometry

side_type

Int enum
  0 = “force two-sided” (default)
  1 = “force single-sided”
  2 = “use mesh sidedness”

set single sidedness of the mesh, will affect the visibility of the mesh based on normal direction

Labels attributes

label

String
default:

label used in material aov expresssions

shadow_receiver_label

String
default:

Label used to associate Geometry objects into ShadowReceiverSets. Using this in combination with the ["shadow_exclusion_mappings"] attribute, shadows from specified geometries or their parts can be suppressed from casting shadows onto one or more specified sets.

Mesh attributes

adaptive_error

Float
default: 0.0

The maximum allowable difference in pixels for subdivison mesh adaptive tessellation (each final tessellated edge won't be longer than n pixels if adaptive error is set to n). A value of 0 disables adaptive tessellation, reverting to uniform tessellation, which sometimes is more stable in animation. Adaptive tessellation is not supported for instances. The maximum tessellation won't exceed the value specified in mesh_resolution. This prevents excessive tessellation when the mesh is extremely close to the camera.

face_vertex_count

IntVector
default: {}

List of vertices per face, used in conjunction with vertices_by_index to construct the mesh

is_subd

Bool
default: True

If true, a SubdivisionMesh primitive will be created - PolygonMesh otherwise

mesh_resolution

Float
default: 2.0

The maximum resolution to tessellate a mesh. An edge on input face will be tessellated to at most n segments when "mesh resolution" is set to n. If "adaptive error" is set to 0, every edge on input face will be uniformly tessellated to "mesh resolution". Otherwise renderer will adaptively tessellate mesh based on camera information

normal_list

Vec3fVector
default: {}

If the mesh is using normals, store them per face-vertex in this list

orientation

Int enum
0 = “right-handed” (default)
1 = “left-handed”

When set to "left-handed", normals are generated using the left-handed rule. This reverses the direction of generated normals, and which side of surfaces is considered the front, without affecting supplied normals.

part_face_count_list

IntVector
default: {}

List of the number of faces belonging to the part with corresponding index in 'part list'.

part_face_indices

IntVector
default: {}

List of face indices. No index should have a value greater than the size of 'face_vertex_count'

part_list

StringVector
default: {}

List of part names, used in conjunction with 'part face count list' and 'part faces indicies' to assign per-part materials

smooth_normal

Bool
default: True

Generates smooth shading normals on a PolygonMesh when the mesh doesn't provide shading normals

subd_boundary

Int enum
  0 = “none”
  1 = “edge only”
  2 = “edge and corner” (default)

Boundary interpolation: Corners, Edges or None

subd_corner_indices

IntVector
default: {}

List of indices for each corner vertex with an assigned sharpness.

subd_corner_sharpnesses

FloatVector
default: {}

Sharpness value for each corner vertex.

subd_crease_indices

IntVector
default: {}

List of vertex index pairs for each crease edge with an assigned sharpness.

subd_crease_sharpnesses

FloatVector
default: {}

Sharpness value for each crease edge.

subd_fvar_linear

Int enum
  0 = “none”
  1 = “corners only” (default)
  2 = “corners plus1”
  3 = “corners plus2”
  4 = “boundaries”
  5 = “all”

Face-varying linear interpolation: None, Corners Only, Corners Plus 1 or Plus 2 (RenderMan), Boundaries, or All

subd_scheme

Int enum
0 = “bilinear”
1 = “catclark” (default)

CatClark or Bilinear

uv_list

Vec2fVector
default: {}

If the mesh is using UVs, store them per face-vertex in this list

vertex_list_0

Vec3fVector
default: {}

List of vertex positions used by the mesh at motion step 0

vertex_list_1

Vec3fVector
default: {}

If the mesh is in motion, the vertex positions for the second motion step are stored in this attribute

vertices_by_index

IntVector
default: {}

List of vertex indices used to construct the mesh using the vertex list

Motion Blur attributes

accleration_list

Vec3fVector
default: {}

Optionally declared vertex accelerations for quadratic motion interpolation

curved_motion_blur_sample_count

Int
default: 10

Number of time samples generated along each curve when using curved motion blur

motion_blur_type

Int enum
  -1 = “best” (default)
  0 = “static”
  1 = “velocity”
  2 = “frame delta”
  3 = “acceleration”
  4 = “hermite”

Motion blur type for PolygonMesh/Points/Curves.
"static" will treat the mesh as static.
"velocity" will blur using the supplied vertex positions and velocities.
"frame delta" will interpolate between the two supplied vertex positions.
"acceleration" will blur using the supplied vertex positions, velocities and accelerations.
"hermite" will use supplied pair of positions and pair of velocities to interpolate along a cubic Hermite curve.
"best" will use choose the method which provides the highest quality given the available data.

primitive_attribute_frame

Int enum
  0 = “first motion step”
  1 = “second motion step”
  2 = “both motion steps” (default)

Which frame(s) do we take the primitive attributes from?
O : first motion step
1 : second motion step
2 : both motion steps

use_rotation_motion_blur

Bool
default: False

If "xform" is time varying and motion blur is enabled, enabling this feature can produce a curved rotation trail. Enabling this feature will disable adaptive tessellation for this mesh

velocity_list_0

Vec3fVector
default: {}

Optionally declared explicit vertex velocities to use instead of vertex positions from a second motion step'

velocity_list_1

Vec3fVector
default: {}

Optionally declared second set of vertex velocities together with vertex positions from the second motion step for cubic motion interpolation

velocity_scale

Float
default: 1.0

Adjusts magnitude of velocity-based motion blur

Ray Tracing attributes

ray_epsilon

Float
default: 0.0

When a secondary ray is fired, anything within this distance of the intersection point will be ignored. Instead, it is considered part of the current intersection's geometry. If zero, an automatically calculated epsilon will be used.

shadow_ray_epsilon

Float
default: 0.0

When a shadow ray is fired, anything within this distance of the intersection point will be ignored. If this value is less than "ray_epsilon", then it has no additional effect.

User Data attributes

primitive_attributes

SceneObject Vector
default: {}

Vector of UserData. Each key/value pair will be added as a primitive attribute of the mesh.

Visibility attributes

visible_diffuse_reflection

Bool
default: True

whether the geometry is visible in diffuse reflection

visible_diffuse_transmission

Bool
default: True

whether the geometry is visible in diffuse transmission

visible_glossy_reflection

Bool
default: True

whether the geometry is visible in glossy reflection.

visible_glossy_transmission

Bool
default: True

whether the geometry is visible in glossy transmission (refraction).

visible_in_camera

Bool
default: True

whether the geometry is visible to camera rays

visible_mirror_reflection

Bool
default: True

whether the geometry is visible in miror reflection.

visible_mirror_transmission

Bool
default: True

whether the geometry is visible in miror transmission (refraction).

visible_shadow

Bool
default: True

whether the geometry casts shadows

visible_volume

Bool
default: True

whether the geometry is visible in indirect volume rays

General attributes

contains_camera

Bool
default: False

Specifies whether the geometry contains the camera and should be used for IOR tracking. This should not be changed by the user -- they should instead attach the relevant geometry to the camera, which will then flag this geometry.

dicing_camera

SceneObject
default: None

Alternate camera that is used for adaptive tessellation. This is useful if you want adaptive tessellation to behave consistently in a sequence, regardless of what the main camera is doing

node_xform

Mat4d blurrable
default: [ [ 1, 0, 0, 0 ], [ 0, 1, 0, 0 ], [ 0, 0, 1, 0 ], [ 0, 0, 0, 1 ] ]

The 4x4 matrix describing the transformation from local space to world space.

references

Geometry Vector
default: {}

list of geometries that geometry procedural can reference during procedural generate/update stages. For example, an instancer geometry procedural can instance primitives generated by the reference geometry procedural.

shadow_exclusion_mappings

String
default:

A space-separated list of mappings of the form A:B where:
A is a comma-separated list of names of parts of this Geometry, or an asterisk to specify the whole geometry;
B is a comma-separated list of shadow receiver set labels established using the ["shadow_receiver_label"] attribute, or an asterisk to specify to all such sets in the scene.
For each of the listed mappings, shadows from the parts specified in A will be suppressed from casting onto any geometries in the ShadowReceiverSets specified in B.
**Note: no part name should appear more than once in the string, otherwise the behavior is undefined.**

static

Bool
default: True

disable if the geometry will be updated between frames

use_explicit_shading_attributes

Bool
default: False

Enable the use of explicit shading attributes (N, dPds, dPdt) if they are present

use_local_camera_motion_blur

Bool
default: False

Enables experimental feature that also attempts to remove the camera blur in the local regions

use_local_motion_blur

Bool
default: False

Enables the local motion blur feature, which makes the geometry procedural responsible for handling all of the geometry's motion and allows for custom effects