When you work with particle-object interaction you normally add a → "Collider" tag to control the collision object's surface properties: friction, bounciness, stickiness, roughness, or velocity factor. By default, these values are valid for the object's entire surface, but it is also possible to use maps instead. This way you will able to get a much more realistic behaviour, for example if you simulate water in a riverbed. In such a case you normally want to define areas with higher or lower friction. You can also control the stickiness or roughness of the stones in the reiverbed riverbed to make fluid residuals "glue" on their surface. With these maps you can distinguish between rough and even stones. Or you add a map to the "Collider" tag's "Bounce" parameter. Or you apply maps to all properties.
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