Page 1

Ramon Brand www.ramonbrand.com

Revision 12 - June - 2014


Contents Introduction .................................................................................................................... 3 Modeling ......................................................................................................................... 4 The basics .................................................................................................................... 4 Shading ....................................................................................................................... 5 Types of Polygons ......................................................................................................... 6 Number of Sides ......................................................................................................... 6 Triangle Explanation ................................................................................................... 7 Poly Flow ................................................................................................................... 8 Applications .................................................................................................................. 9 Blender ..................................................................................................................... 9 Cinema 4D................................................................................................................. 9 3Ds Max .................................................................................................................... 9 Softimage .................................................................................................................. 9 General Tips ............................................................................................................... 10

www.ramonbrand.com

2


Chapter 1 Introduction You have probably heard of a variety of terms here on the forums, many of which are confusing and lead you to make incorrect assumptions. Let’s start out by defining exactly what this is all about. If you want to make a quick number change or name on gear, then these tutorials are not really for you, because we will take a much deeper look into it and try to uncover the most common issues new users come across, especially if they want to take digital art a little further than basic graphic kits and hay bales. Let’s get right into it and discuss how it all fits together. Every object in the game is an asset, and consists of a variety of components that make it appear and behave in the way the specific object does. A basic object in MXS will consist of the following. • • •

Model Material Physics Model

Let’s briefly go through them, starting with the model. The model is the 3D shape that appears in game, whether it is a box, a sphere or a complicated bike, house or stadium. The material is the resultant color that appears on the shape of the model. Lastly, the physics model, along with the hard coding of the game, is what controls how the object behaves, be that moving, rotating or scaling. In the case of MXS, we do not need to worry about the physics model, since this is all hard coded into the game, we can only change the aesthetic aspect of an object, that being the model and the material. Now, you might be wondering, well, how do I make these aspects of the object, and once I have, how do I link it with the correct physics? This is done by either the naming convention of the files you made, which is what the hard coded aspects of the game look for, or through a text or xml file which tells the game which files to load or use. In the case of MXS it’s the first scenario, where the name of your file determines the resultant link in the game. We will cover this in more detail later on. So, knowing this, we have to break our workflow into the three main parts, modeling, materials, and linking. Let’s look at a general overview of each, and then we will go deeper into each as we learn the issues and hurdles in each one.

www.ramonbrand.com

3


Modeling The basics As we have seen, modeling is the process of creating the 3D shape of the object. Before we get to making models, it’s a good idea to understand the theory very well, since the more you understand the theory, the faster you will grasp concepts later down the line. Although the process of modeling might seem daunting, and it can be, it’s better to thoroughly understand the theory so you are able to build slowly, and focus on the software, rather than the results. A model consists of 3 types of entities, each of which is a sub-entity of the last. Let’s start with a vertex. A vertex is a single point in space that has no volume, but an exact x, y and z co-ordinate. A vertex cannot be seen in the game, but it is a reference point on which the next entity will build from, the edge. An edge is the line that connects two vertices, which does NOT have an x, y or z co-ordinate, but joins between two vertices which in turn each have an x, y and z co-ordinate. An edge can also not be seen in game, but is the reference entity for the next entity, a polygon. A polygon is the surface between multiple edges. The most basic form of polygon is a triangle, which has 3 vertices, 3 edges and one face, which forms the polygon. On the above right is an example of a triangle in 3D space. The polygons are used to form the model. Each model consists of polygons connected toghether, which form the overall shape. We will have another tutorial explaining in more depth the process of actually modeling an object. For now we will just concentrate on the process and the hurdles to overcome and understand. Since the model is made up of flat polygons, also known as faces, the model itself is never really smooth, so how do we make rounded surfaces? Well, we add enough faces on the curve so that it seems round enough. The number of edges you use in a curve is decided by how smooth to has to look, and how close up the model will be viewed. Let’s look at a basic model of a Yoshimura. As you can see the shape is formed by connecting flat faces together. What’s important to note, is the difference between the actual hard shape of the model, compared to how the light falls on it, known as the shading, not to be confused with “shading” when people talk about texturing. Below we will compare the difference more closely.

www.ramonbrand.com

4


Shading The following images show the exact same model. The image on the left is the model with hard shading, which is the true shape and look of the object, this is as pure as the object can be displayed. As you can see, the shading is harder on the left and is the exact shade the face should have. The entire face is at the specific angle, and therefore the entire face reflects light at that angle. This is “true” because this is how it would look if the object was indeed a bunch of conjoined flat faces, but the problem with this is that in reality, objects are not made of flat faces, and therefore smooth shading was developed. Smooth shading basically blends the shading to average out between the faces around it, as you can see in the image on the right. Personally I prefer to model in with hard shading because it makes the angles and position of the faces easier to see, but make sure you export the model to MXS or MXB with smooth shading. Now knowing this, we can define sharper and looser edges by changing the distance between edges, since the closer the edges are, the tighter the shading will be. A general rule is, any angle that is less than 91°, should have a chamfer, in order to control the shading. As you can see below to the left, there is a 90° angle, that has no chamfer, and it results in a smooth edge, because the shading smooths to the next edges in the edge ring. If we add a chamfer to this edge, you will see the shading tightens up and the edge becomes more defined. This effect becomes much more apparent and important when the object is interactive and a moving lights can be seen. Adding all the details you might want will mean a considerable number of polygons, not just to get the shape, but also polygons to control the shading, as we have seen above. We need to understand that we ultimately want to keep the number of polygons to a minimum, to allow the computer to process the graphics faster. So if we have to keep the polygon count down and we want details, what do we do? Well, fortunately there is a solution to this, it’s called normal mapping. We will look deeper into this later, but what’s important to know now is that you should model the general shape, and worry about the details later when we get to normal mapping.

www.ramonbrand.com

5


Types of Polygons Number of Sides Polygons can theoretically have any number of sides and vertices. When modeling, you can use polygons with any number of edges, but some types of polygons will have major benefits over others. Let’s start with quads. Quads are polygons with four sides and are the most common type of polygon used in modeling, because it offers many benefits with shading control and deformation, as well as making it easier to control the flow of the polygons. Quads are also easier to select. The middle face in the image on the right is a quad. Another type of polygon is a triangle. Triangles are the simplest type of polygon, and have to always be flat, because any three points with a face joining them will result in a flat surface. This is also a major benefit because it ensures that the shading will be exactly as modeled since the polygon cannot be divided any more. On a flat surface this won’t make a difference, but when the quad is not flat, the quad can have two solutions, one in either diagonal cut, which forms two triangles. When you want to ensure the shading will not change it is usually a good idea to convert your entire model mesh into triangles, because it forces the geometry to be fixed and locked into the shading. This is particularly important when using normal maps which are tangent based, which we will learn about later. On the left you can see the same model, where one is triangulated after it was modeled. Its also important to note, models which are quads can always be triangulated, but triangulated models cannot always be quadrified. Triangles and quads are almost always the only acceptable polygons to use. Polygons with more than four sides will result in weird shaing and artifacts, unless they are used in specific conditions, but these are rare. For a general model, in almost all cases, your model should consist of only triangles and quads. Note that when the model is exported, it is automatically triangulated, but if your shading was different, due to triangulation in the opposite solution, the normal maps will not work correctly, which is another reason to triangulate your model yourself before you export it.

www.ramonbrand.com

6


Triangle Explanation It is important to note, that even though you may be modeling in triangles, quads and any other form of polygon, which is also called an n-gon, the mesh itself is in reality made of triangles in all situations. This is because a triangle is the only polygon which will always be flat, since it consists of only 3 vertices. In the case of a quad or any other polygon, the polygon is automatically split into triangles. This can’t be seen in wireframe view, but the shading is always calculated with triangles. Let’s first look at the triangles within polygons. The image to the right shows a quad, with view triangulation turned on, we can see the cut where the polygon is cut. If we want to turn the triangle, we can click it. You might be asking, why would we want to turn the triangle, well let’s take a look at a situation where it becomes necessary. The image below on the right shows three quads, all with hard shading. You can see the quad clearly is not flat. The quad on the right has to smooth the shading because it doesn’t know the exact shape of the face. On the left we can see the two possible ways the quad can be split. These are made from the exact same shape quad, but produce two different 3D shapes. This is very important when you need to choose the triangulation yourself, such as when you control the shading or when you will create normal maps, which we will learn about later. You can turn the triangulation of a quad by using the specific command in the application, and still maintain the quad, which means you have the advantages of quads, which include flow, selection and deformation. If your chosen application cannot turn the triangulation within a quad, you can force the triangulation by cutting in the triangle with an edge, which will give the exact same result, just without the benefit that quads have. In the image to the left you can see the advantage of quads. The quads allow the mesh to flow very well and smoothly. Keep in mind though, that even though the mesh is composed of quads, the true geometry consists of triangles, being manipulated by quads, in this specific case.

www.ramonbrand.com

7


Poly Flow Poly flow is something I stress more than any other aspect of a 3D model. Some people grasp the concept of poly flow very easily, some not, but either way, its super important to understand what it is and why it is important. Poly flow is basically how well the polygons flow from one to another and how relaxed they are. Relaxed might seem like and odd term, but in essence it is how close the polygons are to what they would “want� to be. What they want would be an equilateral triangle, an exact square or really any shape that is uniform and not to exaggerated in any one direction. The following image shows a comparison between bad and good poly flow. Both have the same shape, but the one on the right clearly has better flow. This will alow for much better shading, and will deform better, alow you to edit it easier, and also interact with your material a lot better. As well as the flow, trying to keep your quads square and your triangles equalateral will also result in better shading and results. I can not stress enough how important good poly flow is. Do not worry to spend time to make sure its perfect, or even remodel the object with a new, cleaner mesh after you have blocked out the original messy shape. I often get asked how long it takes me to model. This is a question that is very difficuilt to answer because it drastically depends on the shape. I will share a quick mental workflow I follow, but bear in mind that it can change drastically depending on the task at hand. I generally start by looking at reference images of the object, be it a shroud, fender or even something as simple as a barpad. I then try to make sure I understand the shape very well in my mind. I need to know where the edges are and what contours to follow. I try to visualize the mesh before I even place down a polygon, but more importantly than visualizing the mesh, is knowing how you plan on making the mesh flow, or atleast have a general idea. In the example above, I would block out the shroud and tank in around 10 minutes, then I would refine the mesh, to flow a little better. I sometimes also rebuild a new mesh in place of the old one, with better flow, now that I have the shape down a little better. This rebuilding of the mesh is known as repotography, and we will cover that in detail later.

www.ramonbrand.com

8


Applications There are many applications for modeling, many of which offer features which are almost never used, and all of them exceed MXS and MXB’s requirement by far. The key thing to remember is that the application you use should be a personal choice and whichever workflow and tool you prefer. Below is a simple list of what I have gathered of some applications, and the advantages and disadvantages. Blender Blender is a 3D application developed by the Blender Foundation. The major benefit of this software is that it is free, entirely free, and will always be. Blender is able to do pretty much anything any application can do, although with my personal experience it’s a little more tedious and not as user friendly. Blender is the native export software for MXS so Blender will be a requirement if you intend to model for MXS, however it can be used for export only and you can still model the actual model in another program. Cinema 4D Cinema 4D, developed by Maxon, is also a great package. The advantage to C4D is the user friendliness to model fast. I personally find I can whip together a rather large model pretty quickly with C4D, but it never seems to be so well rounded off. C4D seems to make most things easier, but some things much harder. The issue I have with this is it skips the foundation and allows you to focus on what you want, which is nice, but it means when things go wrong, you tend to struggle to fix it. Also, C4D seems to be exactly that, more cinema orientated, not really containing so much game asset support. Another major drawback to C4D is the cost, coming in at a whopping 3,695.00 USD. 3Ds Max Developed by Autodesk, 3Ds Max is my software of choice, personally. The advantage of 3Ds is that it’s the most common, industry leading software available, which means most files, plugins and tutorials will be using 3Ds. 3Ds also has great modeling features and although clunky in the past, the latest version of 3Ds have really become streamlined and useful, not to mention the extreme customizability of the UI, which when done right, will dramatically speed up your work flow. 3Ds also has support for a 3D mouse, which if you can make the investment, is well worth it! 3Ds also allows for much more in depth setup with models, scene and even extremely advanced rendering, especially when an external renderer is used, such as VRay, which is excellent. I am in no way associated with Autodesk, but I can personally say, 3Ds Max has its issues, its crashes and its frustrating times, but overall, the best package I have used, by far. Softimage Now known as Autodesk Softimage. I used this application back when Softimage was the developer and the software was called XSi. I am not sure how much has changed, although I believe the software is identical, it was just rebranded under a new developer. When I used XSi it was very user friendly and easy to model, although I found that since it was more aimed towards animation, it was not as versatile as 3Ds Max.

www.ramonbrand.com

9


General Tips Below are some general guidelines to follow, which will speed up your workflow, make it easier, or make your models look better. • • • • • • • • • • • • •

Model out a very basic block shape before adding details. Use quads as much as possible. Ensure quads loop into rings as much as possible. Keep quads as square as possible. Keep quads as planar as possible. Make sure the model’s shape looks correct from all angles. Make sure the polygons flow well. Make sure curves blend well. Remove any entities that do not contribute to shape. Make sure the shading performs as well as possible. Check poly flow and tweak. Check poly flow again and tweak. Think about your LODs as you model.

The table below shows some average numbers of triangles in a model, remember, a quad consists of two triangles and a five sided polygon consists of three triangles. So you are not saving by removing edges. Model Bike

Tri Limit (MXS) 30,000

Tri Limit (MXB) 50,000

Rider

10,000

20,000

Helmet

8,000

14,000

Boots

N/A

12,000

www.ramonbrand.com

10

MXG - Modding Guide - June 2014  
Read more
Read more
Similar to
Popular now
Just for you