Learn to Use Blender - Part 5
Welcome to Part 5 of this tutorial series teaching you how to use blender. I highly recommend that you read through the entirety of the tutorial from start to finish so that you can pick up details that appear in every section.
Last time we talked about cutting our first paint scheme into an aircraft and we started with a simple stripe around the fuselage. To do this we had to learn how to cut the mesh and control the cut paths we create.
Today we are going to take a look at decals; what they are, when we use them, and how they are made. At the end I will introduce the concept of shrink wrapping, which allows us to apply the decal to our models
You can check out Part 1 here.
You can check out Part 2 here.
You can check out Part 3 here.
You can check out Part 4 here.
What Is A Decal?
A decal is essentially a sicker. A decal is an easy way to apply a lot of detail to the aircraft you are painting, without a lot of work cutting the mesh and distorting it. Typically a decal is an independant SRF file that you either made, or took from my decal pack. (You can find my decal pack at the bottom of this page) A typical decal contains some sort of detail that would be hard to cut into the fuselage, such as the name of the airline, or the airline logo.
Why Do We Use Decals?
There are two methods for putting lots of detail into the paint job on an aircraft.
Cut the details directly into the mesh of the aircraft
Use Decals for places where more detail is needed (Airline logos, etc) and only cut what you need to.
Why are there two methods? Which one is better? These questions are a function of two things, what program you are using, and what you skill level is. A lot of the aircraft that feature the direct-cut paint schemes are generally a lot older and used the legacy modding tools. More 'modern' tools like blender make this a lot more complicated. The trade off, is that with the modern tools we gain a lot of scripts and shortcuts that help us speed up the process of painting an aircraft.
A new modder like yourself (or new to blender) will find that it is easier to make your own decals (or use some of mine) to create your paint jobs. By focusing on the content of the decal, rather than how the logo interacts with the fuselage, you will be able to keep frustration levels and the overall complexity of the project down. Using decals also lets you reposition the decal and work on getting things right, giving you a greater degree of flexibility
Where Do We Use Decals?
In general, I use decals for anything that would be complicated to cut into the mesh of the aircraft. Logos, registration texts, country of origin flags, even really complicated tail art are things that I consider doing as a decal. The tail art of the American Airlines aircraft below was made using a decal and then shrinkwrapping it around the blank model's tail fin. You also see the bird logo and airline name, which were also decals.
On the other hand, you will sometimes have situations where cutting general swirls into the fuselage for the paint scheme will prove to be useful. Sometimes stripes around the middle of the fuselage going from nose to tail will be easier to make by cutting the mesh. In the image below you can see some of the ways decals and mesh cutting can compliment each other to create great-looking paints.
How Do You Make A Decal?
Making a decal can take a while. You need to be patient and have an eye towards reducing your workload. To start you will need a reference Image. This means finding an image that looks something like this:
You can find images like this by searching "[Insert airline Name here & ignore brackets] logo"
What you want to avoid are images of the decal or logo that include the plane they are painted on. These will NEVER be straight-on images and it will add a lot of excess that you do not want to deal with. Small differences in angle, and orientation of the camera relative to the aircraft can have a big impact on how the decal you make from it looks.
An example of a BAD image to use for decal making
The above image is a GOOD reference for placing the decals. It can show us where to place the decals relative to windows or another reference length.
Bringing Image into Blender
When bringing an image into blender there a ton of different methods, however we can take a shortcut. As you should already have a project folder for the aircraft you are working on, create a folder for decals. The idea is to reduce the amount of digging through the file browser to find the decals we want to use. By putting them into this folder and then saving the blender file with the decal in the folder as well, you can save time.
Next, save the image you want to use as a reference into the decal folder.
Now open blender and save a blank blender file (with a decal name) into the folder you just saved the reference image into.
Make new subfolder for decals in your project folder
Save image into new decal folder
Save blank blender file into decal folder
Now you simply need to open up the background images menu as shown in the image below.
Select 'Use Background Image'
Click on 'Load' and select the image you want to use.
Now you have your image inside of blender. We can adjust the position of the image using the x and y offset boxes, and also adjust the size of the image. HOWEVER, we do not need to do so when making a decal. When we make a decal all we need are the shapes and colors. Right now we can make the shapes based on the image. Once we have that completed, I will show you how to extract the colors from the image.
You can only view the background image from one of the numberpad view modes. (i.e. Top, side, front and their reverse)
Tracing A Decal
For this portion of the tutorial I will be making a decal of the Boeing logo.
To begin with, we need to identify the parts of the decal we are going to be working on. For this tutorial I want to make the part on the left. I have no words to describe it better than "thingie".
STEP #1: IDENTIFY MAJOR GEOMETRIES
I want to start with something easy to make and that usually limits me to circles, squares, or polygons made from low-vertex circles. Therefore I will make the ring. Two important things
The middle needs to be blank
There needs to be more vertices than a simple circle because this is a thin ring where the vertex count is going to be more evident.
To begin with, I was in the top-down view mode. I added in a mesh circle and leaving it at 32 vertices. This differs from most of the circles I make where I am typically around 20-24 vertices for a maximum.
Then while in EDIT MODE, I moved and re-sized the circle to match up with the inside of the ring.
Now comes the first tricky part. We need to use the Extrude option in blender. Make sure you are in Edit Mode and have all the vertices in the circle selected. We extrude by pressing "E". This opens up the menu below, from which we will select Edges.
Note that when we do so, blender wants to move the circle to where ever we move the mouse.
Until told otherwise, do not click your mouse or press any key other than the ones told. We need to stop moving the new circle by pressing the ESCAPE key. This will snap the new vertices to their original location and overlap with the original circle. Now press "S" in order to open up the scaling option. Drag your mouse until you see the outer circle overlap with the reference image.
It may help to enter the Wireframe View Mode to see through the mesh and see the reference image.
We do not need to make this super accurate if you do not want it to be. The important thing is the general shape. Getting precise matches to the reference images can be achieved, but it can take a long time to do so.
STEP #2 PREPARING FOR ADDITIONAL GEOMETRY
Once you are satisfied with the ring, we need to cut some lines through it to allow for the swoosh and the triangle to intersect and use the same vertices. Rather than make separate shapes and then join them together we will make them one object right from the start. The following series of images shows how I did so for this decal.
STEP #3: TRACING UNIQUE GEOMETRY
Much of the decals we make are unique. This requires is to either adapt an easy geometry (turning a circle into an ellipse) or tracing the edges of the decal by extruding a one or two vertices to form the edge. We will start with the swoosh simply because it looks like it might be easier. There is no correct order to make these in, except to simplify your life.
As you can see I decided to extrude two vertices from the ring in order to more quickly make the required number of vertices. This also ensures that we maximize the number of four-sided shapes we make. Minimizing the number of triangles will reduce the likelihood of shading issues later on. This does NOT mean that every triangle needs to be eliminated. There are times where it is simply not feasible to accomplish the geometry any other way.
Note that I first line up one side of the double vertices with the reference image and then go back to adjust the other side. For the end pieces I merged the two vertices together and made the four-sided shape into a triangle.
With the middle section we again follow the same procedure, but finishing this off proves to be a bit tricky. We will have to create faces by pressing the "F" key after selecting either 3 or 4 vertices. Here I could have made 3 triangles, but instead went with a trapezoid of sorts and a triangle.
For the final side we will first make the first set of faces, because we will only extrude a pair of vertices, rather than extrude a new face like what previously happened.
Unfortunately for us, the curve in the decal is very tight. To get around this we will probably have to have some triangles. For this section I will extrude a single vertex along each side and then fill in the faces afterwards. Note that in the sharp turn I shorten the distance between vertices and in the straighter sections, I lengthen the distance between vertices. This gives me more detail where a cut corner will look funny.
When filling in the faces, I start from the ends and work my way towards the curve. Note that I needed to insert only one triangle. For this, I switched my selection mode to Edge Selection Mode to speed things up. This way I only need to select the two edges on opposite sides of the curve and press "F" rather than select four vertices.
STEP #4: ALIGNING NORMALS
Switch to the Textured View Mode and notice how the faces look.
Note how some of the faces appear white, but others are see-thru. This is because the normals assigned to each faces are pointing either towards us (white faces) or away from us (clear faces). To fix this we need to re-align the normals. Select all the faces and press Control -> n and select Recalculate Normals Outside. Hopefully this will align all the normals so that they are facing you, however there may be times when some or all of the normals are not flipped. To fix this, select the clear faces and then press "w" to open the Specials menu. Select Flip Normals.
STEP #5: PAINTING A DECAL
For this decal which only has one color our job is very easy. However if you are trying to make a decal with more than one color, you will need to make a division in your mesh so that you can have faces with the different colors.
To extract a color from the reference image, you will need to change the blend level of the background image. To do this you will need to open the background image menu and slide the blend bar to 0.00 as shown below. Note how the reference image becomes less faded as you do this.
Now simply enter Vertex Paint Mode and select the color of the background image and paint the decal.
STEP #6: SEE DECAL TUTORIAL FOR MORE
While this tutorial series is all about teaching you to use blender, making decals is a fairly complicated process depending on how in-depth you wish to get. To that end, I have a "How To Make A Decal" tutorial available here. The first part is identical to the above sections and then gets into more complicated techniques.
With what I have shown you here you can create nearly any decal with enough patients and time. The techniques shown in the new tutorial will show you how to simplify and save time.
So What Is Shrinkwrapping?
Shrinkwrapping is blender's method of painting a decal onto the side of the airplane. There are two main options for you to consider.
The first is like applying a sticker to a soda can. The original length of the sticker is how far around the can it will wrap. I typically do not use this method because it will warp how some decals appear. Unfortunately this is the default option, so we have to be aware of it so we can change it.
The second method is called projection and it works similar to a projector used for playing movies. Rather than wrapping the decal around the aircraft, the decal is displayed in the direction indicated until it hits the target object. Wherever it hits the object, it will deform the decal mesh to accommodate it.
In both of these options there is an offset which will create a buffer between the object being shrinkwrapped and the object being shrinkwrapped around. Typically we do not decrease this more than 0.01 meters (The smallest option we can get using the arrow buttons in the box.) so that YSFlight does not try to render the meshes to overlap.
In the next tutorial, we will discuss how to set up our decals for shrinkwrapping as well as make your first shrinkwrap.
You can move on to Part 6 here! (Link will be added when the tutorial has been started)
In this tutorial we will discuss when to paint directly into the mesh, and when to use decals. The general process of creating a decal will be covered and the idea of shrink wrapping will be introduced.
Questions or Comments?
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