Renderer.bounds

Description

The bounding box of the renderer in world space.

This is the axis-aligned bounding box fully enclosing the object in world space.

Using bounds is convenient to make rough approximations about the object's location and its extents. For example, the center property is often a more precise approximation to the center of the object than Transform.position, especially if the object is not symmetrical.

Mesh.bounds and localBounds are similar but they return the bounds in local space.

You can override the default bounding box by setting your own world space bounding box. This is mostly useful when the renderer uses a shader that does custom vertex deformations, and the default bounding box is not accurate.

When you set custom world bounds, the renderer bounding volume no longer automatically tracks Transform component changes. If there is a local space bounding volume override (localBounds) active at the same time, it is ignored and the custom world space bounds are used. Use ResetBounds to remove the custom bounds override. Note that the custom world bounds value is not saved into scenes or prefabs and has to be set from a script at runtime.

using UnityEngine;

public class DrawRendererBounds : MonoBehaviour
{
    // Draws a wireframe box around the selected object,
    // indicating world space bounding volume.
    public void OnDrawGizmosSelected()
    {
        var r = GetComponent<Renderer>();
        if (r == null)
            return;
        var bounds = r.bounds;
        Gizmos.matrix = Matrix4x4.identity;
        Gizmos.color = Color.blue;
        Gizmos.DrawWireCube(bounds.center, bounds.extents * 2);
    }
}

Additional resources: ResetBounds, localBounds, Bounds, Mesh.bounds.