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This operation takes a point cloud in a geometry input and stamps each one into the output layer using a corresponding input layer.
Point attriubtes are used to drive the stamping, allowing SOPs to be used to build complicated effects.
Note
While points can be depth sorted, this is a 2D operation and the resulting stamps are always of camera-facing textures with no perspective transform.
Parameters ¶
Signature
The layer type that the source accepts.
See Signatures for more information.
Color ¶
Background Color
The initial background color.
Background Alpha
The initial background alpha.
Stamp Color
A tint for the stamp.
Stamp Alpha
A scale for the stamped alpha.
Clipping ¶
Shape
If a clipshape
is not provided, this determines the shape of the
stamp. If it is provided, it is treated as an SDF and the zero
contour will determine the cut out shape.
Square
A square.
Circle
A perfect circle.
Scale
A uniform scale for the stamped values. This is multiplied by a
pscale
attribute.
Angle
An angle in degrees to rotate the stamps by. This is added to a
spriterot
for the final angle.
Shape Edge Filter
A filter-scale to apply for filtering the edge of the cutout of a
stamped shape. Zero will make it all or nothing but result in
aliasing, 1
will do the expected level of aliasing for the
current resolution.
Shape Falloff
How much into the shape the falloff region should extend.
Options ¶
Instancing Attributes
Attributes in Houdini can specify instancing either through
sprite
attributes, such as with the Sprite SOP, or through the
standard copy and transform attributes.
Automatic
Detect which attributes to use by what are present.
If orient
, transform
, up
and N
, or up
and v
are present, the standard attributes will be used.
Standard Instancing
Use the standard instancing attributes. These use the
standard attributes such as orient
and up
to construct a
transform for the point. This is then used to compute the
proper spriterot
and spritescale
to match it.
Sprite
Use the standard sprite attributes. This uses spriterot
,
spritescale
, and spriteuv
.
Up Axis
When converting standard instancing attributes, you must know which axis maps to “up” on the stamp.
Rotation from
Which axis is read out to determine the effective rotation, as they may not be consistent in the case of shears, etc.
Number of Stamps
The number of possible stamps to use. These are indexed from zero
with the stamp
attribute.
Filter
The method used to sample the image.
The default value is Box
. See Filters for more information.
Blend Method
When mulitple stamps overlap, this controls how they blend together.
Depth-Sorted Over
The points are pre-sorted by their depth. The farthest ones are rendered first, so closer points paint over them. Because this needs to sort this can be expensive.
Unsorted Depth-Weighted Over
A non-linear weighting is applied that roughly approximates depth-sorting without the need for sorting.
Add
The stamps add together.
Subtract
Each stamp subtracts its value, likely requiring background to start non-zero.
Multiply
Each stamp multiplies its value, likely requiring background to start non-zero.
Maximum
The maximum of each stamp with the current background is used.
Minimum
The minimum of each stamp with the current background is used.
Inputs ¶
size_ref
A representative layer that determines the size of the output image and controls the metadata.
points
Geometry containing points to stamp.
clipshape
An SDF to use as a cut-out for the stamped textures. This allows sharp shapes to be used with arbitrary textures.
pointmask
A mask to select which points will stamp. This is an all-or-nothing mask. It stamps if a point’s location is in this mask, otherwise it doesn’t stamp.
stamp0
A sequence of layers to stamp. Up to a maximum number of
8 layers can be input. The stamp
integer point attribute
can be used to select which one is used.
Outputs ¶
stamp
A layer with the result of the stamping applied.
id
The id
attribute of the point that contributed the most, or
the point number if that attribute isn’t present.
uv
The uv coordinates of the point that contributed the most to this pixel. This is in image space.
See also |