Adding and merging objects during the sculpting process in Blender is a feature I often use. A great addon for this is the BoolTool with which you can execute boolean operations without destroying the quality of your topology.
Here is a simple example to demonstrate some drawbacks when adding objects to your sculptings and how to avoid these using the BoolTool. Let’s start with the following head sculpt:
If you want to create the neck you could add a new cylinder and adjust it’s position and rotation:
Then we would add some edge loops and move around the vertices with proportional editing to create a basic shape of the neck:
And would end up with something like this:
In this wireframe mode (Z key) you can see that the two objects are overlapping. The normal way to combine two objects is to use the Join operation:
But if we would go on sculpting this object we will get the following errors because our topology is not merged correctly, the objects are still overlapping:
And this seams can’t be smoothed away in sculpt mode with a smooth brush.
The Blender addon BoolTool can be used to union the two objects to one object that has a topology that we can sculpt with without getting topological errors. First you have to download and install the BoolTool. After installation (follow the instructions in the readme)
you can select the two objects in Object Mode and use the Direct Union operation:
Now you get one object with a clean topology. Switch to sculpt mode and use a brush like the Clay Strips and enable Dynamic Topology in the Dyntopo panel:
With that brush you can sculpt and smooth the object now without getting ugly seams:
I really hope you liked this sculpting tip. Of course the BoolTool has many other features that we will explore together in another tutorial.