Houdini 22.0 Nodes Copernicus nodes

Sphere Sample Copernicus node

Samples a layer onto a sphere.

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Since 22.0

This node projects images onto a sphere by sampling a source layer as a latitude-longitude map on a sphere. The node looks up the source layer from the spherical direction or sphere intersection (which the Celestial Sphere parameter determines) at each output pixel.

Note

When connected, the size_ref input determines the output’s resolution and its camera and view metadata.

How to

Turn Celestial Sphere on to sample the source layer as a sphere at infinity, which resembles an environment map. This is the default functionality and the output is similar to looking through a window.

Turn Celestial Sphere off to sample a transformable unit sphere and output a mask for pixels that hit the sphere. The output is similar to wrapping the image around a ball.

For example, the following images show how the Celestial Sphere parameter impacts the output of the original source layer.

Before using the Sphere Sample node.
Celestial Sphere is on.
Celestial Sphere is off.

Parameters

Signature

The layer type that the source accepts.

See Signatures for more information.

Filter

The method used to sample the source layer.

See Filters for more information.

Point

Use the nearest pixel with no interpolation.

Bilinear

Linearly interpolate between neighboring pixels.

Box

Average pixels within a box filter.

Bartlett

Use a triangular filter.

Catmull-Rom

Use a sharper cubic filter.

Mitchell

Use a smooth cubic filter with reduced ringing.

B-spline

Use a smooth cubic B-spline filter.

Transform Order

The order in which to apply the transform components (Translate, Rotate, and Scale). Use the second dropdown menu to set the order in which to apply rotations around the X, Y, and Z axes.

Celestial Sphere

Samples the source layer as a sphere at infinity, which makes the output resemble looking through a window. When on, only Rotate affects the sampled direction and the output mask is 1 everywhere.

Turn Celestial Sphere off to sample a transformable unit sphere and output a mask for pixels that hit the sphere. The output is similar to wrapping the image around a ball.

Projection

The projection used to sample the transformable sphere when Celestial Sphere is off.

Perspective

Cast rays from the camera through the output pixels. In this option, rays converge on the camera position.

Orthographic

Cast parallel rays using the view direction.

Translate

The amount to move the sampled sphere in 3D space.

Rotate

The amount in degrees to rotate the sampled sphere along each axis.

Scale

The amount to independently scale the sampled sphere along each axis.

Uniform Scale

The amount to uniformly scale the sampled sphere.

Inputs

size_ref

A representative layer that determines the size of the output image and controls the camera and view information used for the sphere sampling.

source

The source layer to sample as a latitude-longitude sphere map.

Outputs

transform

The source layer sampled onto the sphere.

mask

A mono layer that is 1 where the sphere is sampled and 0 where the view doesn’t hit the sphere. When Celestial Sphere is on, this is 1 everywhere.

See also

Copernicus nodes