Basic Examples (3) 

Normal texture from a grayscale image:

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Normal texture from array data:

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Normal texture from a height map (CC0 source):

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Apply the normal texture to a polygon (MaterialShading requires Wolfram Language 12.3):

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Scope (8) 

Data (3) 

Use elevation data of real world locations:

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Use textures:

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Use graphics:

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Parameters (5) 

Create normal textures with varying strengths:

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Use different vertical and horizontal strengths:

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Negative strength values reverse the normal direction:

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Create normal textures using increasing radii:

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Use different vertical and horizontal radii:

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Options (9) 

Method (4) 

Compute the horizontal and vertical derivatives using the default Sobel method:

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Use the Gaussian method:

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Use custom kernels for computing the derivatives:

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Compare different methods with increasing kernel radii:

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Padding (3) 

By default, a "Fixed" padding is used when convolving the input image:

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Pad with one:

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No padding results in a smaller image:

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OutputRange (2) 

By default, the channels in the output are rescaled to be between 0 and 1:

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Use the range -1 to 1 to leave the normal vectors unscaled:

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Properties and Relations (3) 

NormalTexture produces normal textures compatible with MaterialShading (requires Wolfram Language 12.3):

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The red and green channels of the normal texture correspond to the horizontal and vertical derivatives of the input image:

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NormalTexture calculates derivatives similarly to GradientFilter:

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Possible Issues (2) 

By default, the components of each normal vector are rescaled, causing them to no longer be unit length vectors:

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Use an output range of -1 to 1 to leave the normal vectors unscaled and unit length:

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Neat Examples (2) 

Create a normal texture for the Earth:

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Apply it to the unit sphere to simulate Earth's terrain (MaterialShading requires Wolfram Language 12.3):

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Visualize the normal directions across the implied surface:

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