Did you know you can use a modifier to hide parts of your objects?
In this Blender tutorial I will show you how to use the mask modifier to show and hide parts of your mesh objects in Blender.
Introduction
The mask modifier allows you to hide vertices of an object based on vertex groups
Mask Modifier
I will select the first plane and tab into edit mode
Under the object data properties panel, I will select all of the vertices and add a vertex group
After I rename the vertex group, I assign the vertex group to the plane
In object mode I can now add a mask modifier
I select the vertex group I just assigned to the plane
When I change the threshold from zero to one, notice that the plane disappears
Vertex Selection
There are a couple of ways that you can use the mask modifier to only hide part of an object
I select the second plane and in edit mode, I assign only one-half of the plane to a vertex group
Back in object mode, I add a mask modifier and choose the vertex group
Notice that now, the half of the plane that is not part of the vertex group is hidden
If I use the threshold amount, I can also hide the other half of the plane
If I want the other half of the plane to be visible instead, I can simple invert the mask
Now when I use the threshold amount I can make the first half that I selected appear
Note, the smooth feature will allow me to more smoothly hide and unhide the vertices
Weight Paint
There is also an option of using weight paints to select vertices
I select the third plane and add a vertex group to the entire plane
I then add the mask modifier
In weight paint mode, notice that the entire plane is red – this means that the entire plane is being affected by the vertex group
I will now paint part of the plane using a weight of 0.1
Back in object mode, notice that the part of the plane I painted is now masked out based on the weight paint
There is a way to more smoothly do this with weight paints
I select the fourth plane and add a vertex group and mask modifier
Back in weight paint mode, I select the gradient brush and paint a diagonal gradient on the plane
Back in object mode, I can now have a more gradual masking based upon the weight painting