Dense point cloud can be built straight from depth maps when you follow the old-fashioned workflow. In that case yo have no chance to set the spacing to a given value, but rather it comes out as preset according to the quality chosen your depth maps.
Still you can use tools/point cloud/filter point cloud to resample the cloud afterwards to a given distance
Another way to get a dense cloud is to sample it onto the mesh, and in this modern way you gain the ability to set the desired regular spacing. Choose the mesh as source. The method come with some advantage as well because the dense cloud inherits the consistency of the mesh, and most of the times comes out a lot cleaner and free of disgusting artefacts we often see in old style dense clouds, such as noisy and sky tinted points.
Regards