Interpenetration is when you stick an element of an object through another. In some cases it can be handy, but it isn't always the best idea.
In the early days of 3D, interpenetrating geo saved us a lot of polygons. But engines worked differently then... polygons where expensive.
In this example, if I welded the beam into the block, it would increase the polycount by whopping... wait for it... 6 whole triangles.
But the rules are different now, 3d cards use a whole new set of rules.
The texture takes up more memory than the mesh you save, so if you bake like this, some of the texture will be wasted.
Either way, the saving isn't as big as it used to be.
Now lets say we bake a high poly model onto this, the bake will have artefacts. You have two polys with vastly different normals- so the bake draws the stud details from two angles.
Now look at this bake. Mmmm... looks nice. This is an example of the different between interpenetrating geo and cut in.
By cutting in here, I have four vertices with normals at the point where the beam meets the stone. That changes the bakes normal, resulting in a bake that appears to be organic. That extra geo pays its rent.
Even when you have an object that needs to stick in like this, I will still slice the sticking through part close to touching the face. This puts the vertices in a place I can use them. You can often bend the normals to help blend the object into the other.
I cover this and all the other techniques from decades of polygon and pixel witchery in my forth coming book.
Got a DM question about how to maintain texel density when unwrapping game meshes.
I unwrap using Maya LT at the moment, and it has a feature called get and set under the scale transform of the uv tools.
Got "get" the texel density of a polygon, and the "set" the others.
Maintaining texel density is most important at seams, where it becomes very clear when there is a mismatch between the two.
However the actual truth is you don't have to maintain a perfect texel density across all of a model. Some parts just don't get seen by the player...
For example who gives a rusty old damn if the inside of a character's mouth, guns inside barrel or the underside of cars mudflaps are lower res than everything else?
You can often cheat density to allow key features close to the camera are crip.
Version control for #gamedev is a serious problem you have to get on top of early as an indy.
At one studio, the artists were just sending each other files via chat. They had no source control for maya files, psds or any source assets. Their concept art was on usbs.
A second issue is that artists and programmers work totally differently with their data.
Files fall into two types- you have your text based stuff (ascii) and your data stuff (binary).
A script would be text based, a photoshop or Blender file would be a binary file.
Now when two programmers work on the same text file, you want to merge their work.
But artists pretty much never want to merge their text files.
Artist text files are things like shader code or level scenes. Merging these is going to explode shit badly.
Your passion for games can and will be weaponized against you by companies.
You desperately want to be part of the magic of the thing you love, and will work yourself to burn out point.
You need to keep perspective.
If you are serious about working in the games industry, it will serve you to remember it is an industry that turns passion into profit.
Trade your time wisely for a fair compensation.
My advice is work hard at the start to secure a "NO fund". Savings that you can live on so you can say NO and walk away from a company that is harmful and find a better job.
This can be hard, but resist spending your early earnings on cool stuff until you have this.
So, in closing... the real question isn't which Doctor Who has fucked their respective incarnation of The Master/Missy, the question is which Doctor is the bottom in each incarnation.