The Gravel generator function renders arbitrarily placed, round, little stones with different sizes. This flexible function can also be used to render textures with features like holes, e.g. sponge and cork.

The Synthesis values have the biggest influence to the appearance of the texture. With the Density parameter you can control the overall number of stones. Roughness regulates the complexity of the pattern. Increase the value to add more little stones. The overall size of the stones is manipulated by the Size attribute. Use the Distortion feature to get non-round stones like those illustrated in Image 2. The Noise parameter causes the background being to change from black to a noise pattern.

Utilize the Amplify value to change the brightness of the gravel texture.

Tip: Use the Noise/Erosion function with the Scratch preset to make the gravel (with noise background) look eroded.