3D modeling has come a long way since its early days. It’s not uncommon to find people who still do 3d modeling using pen and paper, but there are many more who have embraced the digital age by turning to 3d software like blender 3d or Maya. However, one of the most basic concepts in 3D modeling – what meshes are – is often misunderstood by new 3D artists. In this article, we’ll explore what meshes are and how they work!
The Components of a Mesh in 3D Modeling
Meshes are one of the most essential components in 3D modeling. Basically, a mesh is any object that an artist can manipulate to form different shapes and forms. When a mesh is being created, usually the first step is to create the shape. Think of this as creating an outline or wireframe that can be filled in later with color and texture! This would make sense if you think about it – one way to fill something in on paper would be to draw around it.
In 3D modeling, we refer to three basic components that make up a mesh. The first component is the “points” of a mesh, the second component is the “edges” of a mesh and the third component are the “faces” of a mesh.
Points are what we use to create the shape of an object and they can be connected by edges. The points of a mesh are usually just a collection of tips that make up the very outer edge of the entire mesh. Points make up the shape or outline of something in 3D modeling, much like how your pen would create the lines on paper when drawing around shapes. Once you have more than one point, you should be able to connect them; and this connection is then referred to as an edge.
Edges will then connect at or near points, forming faces that make up a 3D model. Edges can be told apart from points because a point is often represented by a small dot, and an edge is most often represented as a line.
Think about a square for an example. A square will have four points. Between these four points, we will draw four edges that connect them all. Now that we have an ‘enclosed’ shape, we will be able to say that we have a ‘face‘, too!
In 3D modeling, we refer to any enclosed shape or polygon as a face. In order for faces to form in a model, there need to be more than three points and three edges. Therefore, it is safe to say that the very most basic form of face there is in 3D modeling is a triangle.
Different types of Meshes in 3D Modeling
Meshes are a collection of interconnected points, edges, and faces. There are many types of meshes; for example: polygonal mesh, subdivision surface mesh (often called ‘subd’ for short), and NURBS.
In 3D modeling, a polygonal mesh is made up of faces that are in the form of polygons – usually triangles or quads (four-sided shapes) but can be hexagons as well.
If a polygonal mesh is made up of triangles (the most basic form of meshes) then it is said to have a triangular typology. If the polygonal mesh is made up of squares instead of triangles, then it is said to have a square typology. If it has an angular typology then it is said to be made of polygons with more than four edges.
There are certain times when square typology (quads) is better than triangular typology (tri’s). If a polygonal mesh is made up of quads, then it will have an even number of edges. This means that the surface should be completely flat for any given plane when 3d printing in order to maintain accuracy and quality. If a mesh is made up of quads, it is also better to animate. So, if you’re looking at 3D modeling some characters, then square typology is for you!
Subdivision Surface Mesh
A subdivision surface mesh is also made up of polygons on the surface of an object, but these polygons are not flat like a polygonal mesh. They are actually made up of many quads. This means that there is a certain amount of distortion (curving) on the surface plane, which makes it harder to 3d print accurately and with high quality.
Polygonal Mesh or Subdivision Surface Mesh?
To decide what type of mesh you’re looking for in your 3D modeling, you will need to consider the following factors:
– How detailed do you want or need your model to be? If you need it to be very detailed and you aren’t worried about your polycount, then you will probably need to consider following a triangular typology.
– Can the 3D printer print details on a polygonal mesh, such as curves and corners? If not, stick to quads.
– What is the purpose of this modeling project? Is it for animation purposes (quads) or for printing purposes (subdivision surface)?
NURBS stands for Non-Uniform Rational B-Splines and is usually used to create curves that cannot be expressed as any other type of curve. NURBS can also be converted into Polygons if needed.
A NURBS Mesh is a mesh that contains curves. You can create one with 3D modeling software such as Blender 3D and not basic hard surface modeling software like SketchUp.
How to Edit your Mesh in Blender 3D
Mesh editing is done by clicking on the object you want to edit and then switching between the Edit Mode and Move Tool. You can also change modes from Object Mode to Edge mode in order to create curves or corners for more intricate designs. To switch between edit mode and object mode, hit TAB on your keyboard.
I have personally found Blender 3D useful because once in Edit Mode, you can switch between editing the points, edges, or faces of your mesh. The default is to have your mesh in Edge mode, which can be changed by clicking on the square icon on the top left corner of your window.
What is Polycount and Why does it matter?
Polycount is the number of faces in a 3D object. The higher polycount, also called high-res meshes, are more detailed and realistic than low-poly objects with less detail. However, this detail does not come without a price. High detail meshes take up more system memory and render effects might not be visible on these high-res objects.
Polycount is one of the most important factors for 3D objects because it determines how your design will look in a game engine or other 3D applications. For example, if you are making a low polygon object (low-poly) to put into a gaming engine like Unity or Unreal, the real-time rendering of your mesh will run a lot quicker than if you had a high polycount (high-poly).
Polycount is such an essential component to 3D modeling that it has its own subset in the 3D modeling software Blender. On its project page, you can see a spot to specify your desired polycount or resolution for the object that you’re creating.
The recent advances in mesh technology have enabled artists and designers to create high-quality models at low cost without compromising on performance through new techniques such as decimation – also a deformer and new tool that can be used in Blender 3D.
Fortunately, 3D artists have found a way to merge the amazing aesthetics of high-poly models with the performance of low-poly models, and this is done through baking normal maps.
What does it mean to Bake a Mesh?
Baking a mesh means using the Normal Map to make it look like an object with more polygons without actually having any more.
A normal map is an image that will be applied to the mesh similar to a texture, but the normal map will specify where a bump in the surface should be. These indications of bump and height in an object can help us represent detail in our meshes, without actually having to have those details affect our polycount.
The process is called baking because it’s like taking an object from one state and turning it into another (like as if you baked an apple pie).
Normal Maps are often used for 3D models that need to have high-resolution textures but low polygon counts, such as many of the objects in video games.
To bake a high-poly to low-poly normal map, a 3D artist would typically apply the following technique:
- Model a high-resolution, high-poly 3D model with all the details in the mesh.
- Make a copy of the high-poly model.
- Reduce the number of polygons in the copy by deleting excessive points, edges, and faces.
- Rename the copy as ‘low-poly.
- Optimize the low poly model by unwrapping its UVs, allocating material IDs, and ensuring its origin is appropriate.
- Using software like Substance Painter or Marmoset Toolbag, apply a high-resolution texture to the low poly object.
- Export the Normal Map from Substance Painter or Marmoset Toolbag and save it as an image file.
- Use Blender’s UV/Image Editor (SHIFT + T) to import the normal map image file into your scene, so you can see how it affects your 3D.
In conclusion, meshes are points, edges, and faces that have been created by assembling many smaller pieces. 3D meshes can be manipulated easily and can either be very detailed or they could be low-poly. What did you think about this article? Please leave your thoughts in the comments below!