White Noise Texture Node

Note

This node is ported from shader nodes. The manual and images are referencing the shader version of the node. This node accepts field inputs and outputs. When not connected the Vector input has an implicit position attribute value.

The White Noise Texture node returns a random number based on an input Seed. The seed can be a number, a 2D vector, a 3D vector, or a 4D vector; depending on the Dimensions property. The output number ranges between zero and one.

White Noise Texture Node.

輸入

The inputs are dynamic, they become available if needed depending on the node properties.

Vector

Vector used as seed in 2D, 3D, and 4D dimensions.

W

Value used as seed in 1D and 4D dimensions.

屬性

Dimensions

The dimensions of the space to evaluate the noise in.

1D

The W input is used as seed.

2D

The X and Y components of the Vector input are used as seed.

3D

The Vector input is used as seed.

4D

Both the Vector input and the W input are used as seed.

輸出

Value

Output random value.

色彩

Output random color.

Notes

The slightest difference in seed values would result in completely different outputs. Consequently, bad precision may have significant impact on the output. Usually, we can mitigate this issue by:

  • Eliminating the problematic seed value. If the problematic seed value is constant, it should be eliminated by choosing a lower dimension or multiplying it by zero.

  • Adding an arbitrary value to the seed. The issue might only happen at certain boundaries, like unit boundaries, so simply adding an arbitrary value might solve the issue.

  • Taking the absolute value of the seed. In computing, zero may be positive or negative, so taking the absolute values unifies the zero into a single value.

../../../_images/render_shader-nodes_textures_white-noise_issue.png

Precision issue due to signed zeros on the Z axis.
../../../_images/render_shader-nodes_textures_white-noise_solution1.png

Mitigating the issue by eliminating the Z axis.
../../../_images/render_shader-nodes_textures_white-noise_solution2.png

Mitigating the issue by adding an arbitrary value.
../../../_images/render_shader-nodes_textures_white-noise_solution3.png

Mitigating the issue by taking the absolute value.

範例

../../../_images/render_shader-nodes_textures_white-noise_solution1.png

Generating cell noise using the Snap vector operation and the White Noise node.