How To Make A Decal

Introduction

This tutorial will show you how to create a decal from nothing but a reference image and discuss increasingly more difficult, but time-saving techniques for making decals. If you have been following my Learn To Use Blender series, you will recognize that the first part of this is exactly the same as Lesson #5. I felt that expanding upon that tutorial here to collect all the major tools and techniques would be helpful for people who don't wish to dig through the Learn To Use Blender series.

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.

A moderately complex decal.

Why Do We Use Decals?

There are two methods for putting lots of detail into the paint job on an aircraft.

  1. Cut the details directly into the mesh of the aircraft
  2. 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.

  1. Make new subfolder for decals in your project folder
  2. Save image into new decal folder
  3. 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.

IMPORTANT NOTE:

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

  1. The middle needs to be blank
  2. 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.

End of the Learn to Use Blender Tutorial

Summary of steps for making a decal so far:

  1. Identify Reference Images
    • Isolated logo images (not from photograph) should be prefered.
  2. Load Images as background image into blender.
  3. Make basic Decal:
    1. Identify simple geometries that can be added with default mesh tools
    2. Prep the first set of geometries for adding other features
    3. Trace out the unique geometries using extrusion.
    4. Align the normals to one direction.
    5. Paint the Decal using the reference image as a color sample.

Intermediate Technique: Using Curves

Now that we have a foundation to build from, we are should look to more complicated tools. One of the easier to use, which segways nicely into the more advanced parts of this tutorial, is the use of curves.

What is a Curve?

In blender, a Curve is a type of object where you can create organic shapes very easily. There are four types, however we will only be working with Bezier Curves. I encourage you to explore these other options to see what capabilities you can gain thru them.

You can access this menu via:

Spacebar -> add -> Curve -> Bezier Curve

Controlling a Curve's Shape

At a minimum a curve is defined by six points split between End Points and Control Points.

By moving these points we can change how the curve is oriented. The distance the control points are away from their respective endpoint, the straighter the line is right by the end point.

It can be very challenging to get the curve to overlap exactly with a reference image. The important thing with this is that we get the shape of the curve close enough so that we can go in later and quickly adjust it back to where we want it. I find, however, that for simple curves very similar to the swoosh in the Boeing Logo, that a curve can sometimes be the fastest way to create the geometry.

If you find that one curve is not enough, you can extrude or cut a curve as if it was a normal mesh. This will create another end point in the middle of the overall curve, something like in the image below. This will allow you to create more complicated shapes, but the problem quickly arises that you start rapidly increasing the number of vertices in the curve.

You can sometimes get away with only one curve (rather than extend or cut the curve you are working with) if you increase the number of vertices, or resolution, of the curve.

Altering Curve Resolution

If you look closely at the image above, you can see that where the curve becomes very sharp, you can see that this curve is really made up of short segments, rather than a continuous curve. To increase the resolution of the curve, you will need to adjust the DefResolU option in the button window. This controls the number of vertices in a segment of the curve. By default there will be 12 vertices, so if you cut or extrude the curve as in the image above, you will now have 24 vertices. You can easily imagine how quickly the vertex count can rise when striving for precise detail with the curves. Therefore, there may be times when we want to reduce the number of vertices in a curve so that you can add more segments to the curve.

Convert To Mesh

As with everything we do in blender, at the end, all the components of our aircraft must be a mesh object in order for the export scripts to work properly. To do this we can go through two options to access the Convert Object Type controls. The first is via the object menu at the bottom of the 3D window as seen in the screenshot to the left.

The other option is to use the keyboard shortcut seen in this image.

Alt -> "c"

This will open up a dialog window that looks something like this:

It should be noted that the only option for converting a curve is to go to a mesh. There are other types of objects that we use in blender for YSFlight Modeling that will have several options in this menu. If you press Return or simply click on the Mesh text, the curve will become a mesh object with vertices as you can see in the image below.

There are many things you can do with curves, but I think you can appreciate the power for simplifying complex geometries by using curves. The following Logo was made by me with extensive use of Curves.

Advanced Techniques - Using Text

Many times you will see Logos or Decals that have significant amounts of text in them. Here are some examples:

All of these logos might be seen on an aircraft, and thus it stands to reason that we may want to make them at some point. However, as you have probably found out by now, tracing out a decal, or even using curves, can take some time to develop a decal. For some unique texts as in the Garuda Indonesia logo above, it is unavoidable, however for other logos like the American Airlines or Boeing Logos shown above, these fonts, or a font very close to the true font can be found online. A google search for "[Airline Name] Logo Font" can usually point you to some useful resources.

By taking advantage of Blender's Text Object and its ability to load any nearly any font with a common format, we can create these decals with significantly less work than before.

While you may need to download a new font (for Boeing as an example) you might find that a font already on your computer (Times New Roman for example). When we are looking for fonts we want to find .ttf files. Personally I recommend doing some research into what font is closest to a logo, as people around the internet have already asked that question in their efforts to replicate it. Who knows? You may just find the exact font used!

Add In A New Text Object

Just like with a curve, Blender treats text as a separate object-type. To add one in, we use the following path:

Spacebar -> add -> Text

This will add in a new object that interestingly enough says "Text" located where ever your 3D cursor is located. Additionally when you select it, you will see two new boxes appear in the button window. The one on the left is one you are already familiar with as it has to do with the curves we discussed in the above section.

When you enter Edit Mode, you will see that there are no vertices. Instead there is a cursor that is a light grey. You can move this around with the arrow keys and type just like you would normally do in a word-processor.

Now that you have inserted a text object, and you have made it say what you want it to, it is time to make sure the font is correct. If you look at the Font box in the button window, you can see that the top left drop down menu says "<builtin>". This is also known to the YS Modding Community as the Default Font for simple projects this may be just what you need, but we can take advantage of blender's usefulness and load a new font.

Load A New Font

As was mentioned perviously, you can find numerous free fonts online that could have uses in YSFlight including digital readouts, old Airline Logos, the basic font used for most registration numbers and US military aircraft designations. The last two examples can be found in the YS Paint Kit, or in my most recent Decal Pack. In general, a .ttf or .ttc font file format will be read by blender.

Whenever I use a font for a project, I place the original font file into my project folder. This makes it easy for me to find the file within Blender's file browser. You should be aware that whenever you open a new session of blender (i.e. close and re-open blender some time later) you will have to re-load the font again for new text objects. Previously made text objects that were assigned a font will retain the font.

To load a new font, press the Load button in the Font button window box. Browse to the font file and then click load. When you have successfully loaded a font into blender you can click on the drop-down menu next to the load button and see which fonts are loaded and select one for use.

Now the text object you have selected will use the font you have selected.

Manipulating Text Object Looks

When you want to make the text object look a little funky or you need it italicized, play around with the options in the Font box in the button window. The image below has several options changed from their default values.

Text On A Curve

For the patch for CVN-68 at the beginning of this section, you can see that the text is wrapped around a circle. This is not as easy to do as it seems from first blush. As you can see in the center left side of the font box, there is a place to enter the object name of a curve called TextOnCurve. What this does is use an existing curve (Both types work for this, so don't be afraid to chose one type of curve over the other) to define a path the text needs to follow. When you enter the name into the TextOnCurve box, the Text object will adapt the curve's properties, but NOT move to the curve. This allows you to separately manipulate curve and see the changes made to the text. I include the text on a curve under the text manipulating section because this is probably the most advanced manipulation that you will need to make anything for YSFlight. Period.

There a couple of methods for inserting the name of a curve into the TextOnCurve box.

  1. Type it in manually (longish, and bound to have errors on occasion)
  2. Copy-Paste the name from the Transform Properties window.

As you can probably imagine the second method is the one I recommend. I have adopted this method for whenever I am working with modifiers which also requires a similar input of object names. As you can see in the image below sometimes object names can have capital letters which can mess you up slightly when inserting text (I know they make me mess up!).

When you press return to insert the text, you will see your text object do something like this:

This makes the line the bottom of each letter rests on, the outside edge of the circle. You can rotate this text object around so that it lines up where you want to set it. For example this could be rotated to be the top text on the CVN decal.

If you try to follow the above method to get the bottom text for the CVN decal, you will quickly find that it doesn't work. In stead, we need to have an open curve (i.e. not a bezier circle) and then apply the text on curve. Then you simply have to position the curve such that it causes the text the closely resemble the decal on the bottom of the circle.

Converting Text To Mesh

When you are satisfied with how the text physically looks, it is time to convert the text to a mesh object. Now before you proceed, please read the following section in full. I am going to show you what to do after I explain why we are going to do what is needed.

Converting text to mesh is very simple. You use the Alt -> "c" shortcut shown in the curves section above, but this time there are more options, and these options have important consequences.

Note the option to convert the text object into a curve object. This indicates that there is a relationship that we can take advantage of in order to reduce the number of vertices and still maintain the form and function of the text decal.

If you look down into the button window, you will see the Curve sub-window to the left of the Font sub-window. Just like with a curve, we can change the number of vertices assigned to each segment in the font.

As you can see, the default font has a lot of curve segments 'hidden' in how the font is done. If you reduce the number of segments in each curve, we can significantly reduce the additional lag this decal will create.

NOTE: You do not need to first convert the text to a curve in order to reduce the resolution of the text object, it can be done before you convert anything in the curve window as you see in this image.

The following images shows the progression from a resolution of 1 to 5 so you can see how small a resolution you really need to have in order to have a decently detailed decal. One thing to note, is that the final size of this text will be a factor in how much resolution you use. A larger text decal will need a higher resolution than a smaller one.

1.

2.

3.

4.

5.

I generally do not go much above 3 or for for resolution unless there is a particular curve that will not look good without a higher resolution.

Now that we have the text looking good, and at the correct resolution, go ahead and convert it to a mesh using:

Alt -> "c"

If you desire to do so, you can then clean up the mesh a little bit and remove some triangles, but it is not 100 percent necessary to do this. I recommend that you do, but this clean up can take quite some time. One really fast shortcut is to select the entire mesh in Edit Mode and use the shortcut:

Ctrl -> "j"

This automatically converts some triangle faces into quadrilateral faces, thus reducing lag, but is not as good as going in and manually taking care of business.

Things To Watch Out For

When making any decal you want to get the most bang for your buck. This means to minimize the number of vertices and faces wherever possible, but not at the sacrifice of the overall accuracy of quality of your decal. By removing triangles and combining them into quadrilateral faces, you reduce the number of faces. By reducing the number of vertices, you also reduce the face count.

Take your time and be patient with the initial making of the decal, because it can be a pain to redo it later if you decide that it is not good enough.

In general I save my decals as their own blender files, and then export them as SRF files. If I need to change a color or make some other edit, I save myself the step of importing the old SRF file and then working on it. It also makes it easier to pass the file on to other people (Like with my Decal packs).

Questions or Comments?

If you have any questions or Comments, you can direct them to this topic on ysfhq.com or get in touch with me via my contacts page.

Image Notes:

All images are the property of their respective copyright and trademark holders. Their use here is not intended to violate any copyright laws as they are being solely used for educational purposes. This is pursuant to the Fair Use section of US copyright law.