You were speaking about blender or daz3d, does daz has this option??
There are two kinds of smoothing in Daz, one is in the surface tab, this should be on by default for most items (this is also the one that Blender does as well).
The other was what I was talking about there. A smoothing modifier is something that Daz adds to an item (Edit/Object/Geometry/Smoothing Modifier), like clothing or a blanket, that will try to help wrap the item around the person or whatever. It will automatically deform the geometry to try to match the item it was set to 'smooth' around. For example, a shirt would want the smoothing mod to be set to the model it is on (usually done by default), this will help prevent clipping from the shirt and the character.
Another example, say you are laying someone in a field of grass, and that grass is clipping through your character's legs or something, you select the grass, add the smoothing mod, set it to work on the character, and no more clipping. Or maybe you might want to have it affect the blanket they are laying on, so that pushes down the grass instead. There are many uses for this trick.
The down side of this is that it will deform the geometry of the object, and this not only needs that item to have enough geometry to work, but also if you are not careful, it can clip the wrong way. Like if you have pants with the smoothing mod, and you try to rest their hand on their hip, the pants might try to wrap around the hand if it gets too close.
If that fails, the only other options would be to use Mesh Grabber (addon), or to use the geometry editor to hide or delete the clipping parts. Well, unless you want to get really technical and export the item into Blender and make a morph or something.