The Delete SOP deletes input geometry as selected by a group specification or a geometry selection by using either of the three selection options: by entity number, by a bounding volume, and by entity (primitive/point) normals. You can choose to delete the selected or the non-selected geometry.
Parameters - Page
group - The name of the group to be created. The default name is set to match the name of the SOP.
negate - ⊞ - Choose to Delete the Selected Geometry or Delete the Non-Selected Geometry.
- Delete Selected
- Delete Non-Selected
entity - ⊞ - Choose to delete primitives or points.
geotype - ⊞ - Select the geometry type group. The selection will only pertain to the geometry type specified. e.g. If you only wanted to group polygons.
- All Types
all- All geometry will be selected.
- Bezier Curve
- Bezier Surface
- NURBS Curve
- NURBS Surface
- Triangle Strip
- Triangle Fan
Parameters - Number Page
Allows selection of grouping of entities by number. When checked, the options relative to this selection option are displayed.
usenumber - When the Enable button is checked under the Number button, the selection options become active and can be used to select entities. The fields available are listed below.
groupop - ⊞ - When the Number Enable button is checked, this option groups entities based on a defined Pattern or by a Range.
- Delete by Pattern
pattern- Select a pattern in the Pattern field below.
- Delete by Range
range- Select a Range using the Start/End and Select_of_ fields below.
- Delete by Expression
filter- Select a range using the Filter Expression field below.
pattern - Activated when Operation is set to Group by Pattern. In this field, enter the range of primitives to select. The required syntax is "S.P", where S is the index of the parent surface, and P the profile index on that surface. You can mix primitives with profiles in the list. A mixed group is automatically ordered.
0.4 2 4 2.5 3.7 selects three profiles and two primitives
0-100:2 selects every other number from 0 to 100
0-10:2,3 selects every two of three
0.0-6 selects six profiles on primitive 0
0.* selects all profiles on primitive 0
!4 selects every primitive or point except the fourth
9-0 selects first ten (in reverse if ordered flag is on)
!0.* selects all profiles except those on primitive 0
* selects all primitives or points, and no profiles
See Pattern Matching in the [Scripting Guide]
Start / End
range - ⊞ - Activated when Operation is set to Group by Range. Select the start and end of the primitive/point number selection.
Select _ of _
select - ⊞ - Activated when Operation is set to Group by Range. Select every nth occurrence of every mth entity in the above Start/End range.
For example; entering 1 and 2 selects 1 out of every 2 entities
filter - The Filter Expression provided is evaluated for every point/primitive. Wherever it is true, the entity is added to the selection.
Parameters - Bounding Volume Page
This option is used for selecting entities based on bounding volumes: Bounding Box, or Bounding Sphere. When checked, the options relative to this selection option are displayed.
usebounds - When the Enable button is checked under the Bounding button, the selection options become active and can be used to select entities. The fields available are listed below. The bounding volume can be seen in the viewport as guide geometry.
boundtype - ⊞ - Selects the type of bounding volume to use:
- Bounding Box
usebbox- Bounding Box entities contained within the box are selected.
- Bounding Sphere
usebsphere- Bounding Sphere entities contained within the sphere are selected.
size - ⊞ - Dimensions of either the Bounding Box or Bounding Sphere in X, Y and Z.
t - ⊞ - The X, Y, and Z coordinates of the center of the bounding volume.
Parameters - Normal Page
This option is used for selecting entities based on the angle of the entity normals. When checked, the options relative to this selection option are displayed.
usenormal - When the Enable button is checked under the Normal button, the selection options become active and can be used to select entities. The fields available are listed below.
The primary axis and the spread angle from the defined axis define a range of angles. If any entity normals lie within this range, then the associated entity is selected.
For example; if you want to select the polygons that are very steep in a polygon mountain terrain on the XZ axis. You would set the Direction to be
0, 1, 0 and the spread angle to around 75. This selects all the polygons with normals that lie flat to fairly sloped. You will have grouped all of the polygons that lie flat up to polys that are at a 75 angle from the axis. You are left with all of the polygons that are 76 or greater.
dir - ⊞ - The default values of
0, 1, 0 create a normal vector straight up in Y, which is perpendicular to the XZ plane, which becomes the primary axis. The
1, 0, 0 points the normal in positive X, giving a normal axis perpendicular to the YZ. The plane may be positioned at an angle by using values typed in (
1, 1, 0 gives a 45 angle plane) or interactively by using the direction vector jack. Values between 0 and 1 should be used.
angle - The value entered in this field generates an angle of deviation from the primary axis. This can be visualized as a cone where the radius of the base of the cone is defined by the Spread Angle and the axis of the cone is determined by the Direction axis. Viewing the primitive normals in the viewport, you can see that any primitives with normals that have an angle that lies in the range of angles defined by the cone will be selected and grouped.
camera - This menu allows you to select an object. Typically, a camera object would be chosen. The primitives which are backface when viewed from the object specified will be grouped or selected.
Delete Unused Groups
removegrp - If any group has 0 entries and if this parameter is enabled, then those groups are removed. If you want to keep empty groups, disable this parameter.
Delete Geometry, Keep Points
keeppoints - Deletes the geometry but keeps the points.
- Input 0: -
Info CHOP Channels
Extra Information for the Delete SOP can be accessed via an Info CHOP.
Common SOP Info Channels
- num_points - Number of points in this SOP.
- num_prims - Number of primitives in this SOP.
- num_particles - Number of particles in this SOP.
- last_vbo_update_time - Time spent in another thread updating geometry data on the GPU from the SOP's CPU data. As it is part of another thread, this time is not part of the usual frame time.
- last_meta_vbo_update_time - Time spent in another thread updating meta surface geometry data (such as metaballs or nurbs) on the GPU from the SOP's CPU data. As it is part of another thread, this time is not part of the usual frame time.
Common Operator Info Channels
- total_cooks - Number of times the operator has cooked since the process started.
- cook_time - Duration of the last cook in milliseconds.
- cook_frame - Frame number when this operator was last cooked relative to the component timeline.
- cook_abs_frame - Frame number when this operator was last cooked relative to the absolute time.
- cook_start_time - Time in milliseconds at which the operator started cooking in the frame it was cooked.
- cook_end_time - Time in milliseconds at which the operator finished cooking in the frame it was cooked.
- cooked_this_frame - 1 if operator was cooked this frame.
- warnings - Number of warnings in this operator if any.
- errors - Number of errors in this operator if any.