Bringing CC4 Cel-Shaded Character into iClone 8 and Unreal Engine 5
José Antonio Tijerín
In this Part 1 tutorial, Digital Artist José Tijerín elaborates on the process of applying cel-shading in Character Creator 4 to visualize 3D cartoon characters as hand-drawn 2D animation in the classic Disney style—one of the greatest advantages being the speed of production for games and films.
José Tijerín is a digital illustrator, 3D sculptor, and creator of video games such as “Dear Althea” available on Steam. His content pack “We’re Besties” is currently for sale in the Reallusion content store.
Character Creator 4 is the best option
This is a basic guide to creating 3D cartoon characters with a cel-shaded style. The aim is to mimic old 2D cartoons that were made in the traditional hand-drawn way. Besides mentioning Reallusion Software such as the benefits of the latest Character Creator 4 (CC4) update, this article will also offer some unique tips, which are also available in the aforementioned video.
The main advantage of creating a character in Character Creator (CC) for me is the ability to directly visualize the final result by applying a cel-shaded effect that makes it look like it was made for 2D animation. As we shall see below, this makes the modeling easier and allows us to make corrections in a simple and intuitive way. The other great advantage is that CC is the ideal program to create this kind of character due to the ability to customize expressions, besides getting professional and functional models. I’ll expound on these amazing features in the latter half of this article, but first, let’s talk about the merits of adopting a cartoonish look.
Benefits of Cartoonish look
A 3D character that imitates a 2D character has many advantages that can speed up the production of a video game or any film work. Without the need to use complex materials full of textures or the implementation of complex lighting systems, we are dealing with works that do not require a lot of processing and that do not give as many technical problems compared to projects with aesthetics that want to approach realism. This is an advantage that I discovered while creating my current game in development “The Evil Furry” (available on Steam wishlist).
For this tutorial I’m going to use characters from this project because, most of it, is created from cinematics; so this tutorial will be useful for creators of any audiovisual product.
2D cartoon character in classic Disney style
The character we are going to create will be for the Unreal Engine in which it will be used in cinematic scenes, but this method can also be used in not so cinematic video games. With this in mind I recommend, as always, be clear about the description of the character and the actions they will undertake in the story.
In this case it is a young girl who appears in a specific part of the story pretending to be a banished princess. She is a carefree, sweet person who dresses in poor clothes and who ends up falling in love with the protagonist of the story. With this in mind and the cartoon style of the Disney film “Snow White“, I looked for the perfect references and explored different designs until I found this one you can see. In my case it has been very useful to look for concept art of the Disney film to be able to see what ideas were being considered and to really understand the film’s style of drawing.
It is of vital importance that your entire project is consistent in style to be considered a solidly professional and credible work. As you can see, I didn’t completely copy the style of the film, but the bases are the same; a main character animated by rotoscoping with flat colors, without light or excess most of the time, with unsaturated colors, hand-drawn backgrounds and with very contained expressions for a cartoon animation. We will see these issues later, but for now let’s start working with Character Creator.
Cel shading effect in Character Creator 4
The first thing we will do when we open Character Creator is to select the cel-shading effect in the “Atmosphere” folder in the Stage section. Inside we can find the “Toon Shader” folder with cartoon filters; I’m going to choose Line Art. The effect has not turned out the way we wanted it to, so we will have to customize it a bit. If we go to the Visual section we can deactivate Post Effect and Global Illumination. In the Toon Shader section, we can configure the effect to increase the thickness of the line and its intensity. In my case, I will also remove all the lighting from the model to make it more faithful to the reference. Finally, if we go to the main menu in the Visual section, we can activate the IBL and change the color of the ambient light from blue to white to see the real color of the textures on the model.
Obviously, these textures are not cartoonish, so we will have to change them to flat colors in a program such as Clipstudio. When placing them on the model, remember to remove the normal textures from all materials. This is because the normal textures affect the outlines in the cel-shading and can be confusing. Leaving them on would not affect the final result in Unreal but I recommend removing all textures other than the base color. In the case of the eyes, it will also be necessary to change the shader type from “Digital human eye” to “Traditional“. to make the texture appear clean and without post-processing. In the case of eyebrows, we can be extra creative by being able to decide their shape through opacity. Remember that you can also make them completely transparent if you don’t want your model to have eyelashes like Mickey Mouse.
I recommend that you use simple shapes and look at your references to check that the result is appropriate; This is a very important element in the expressiveness of the animated character. Another useful trick is, knowing that Character Creator has eight sets of tabs, leave the upper and lower assemblies invisible to avoid extraneous effects and to achieve a better visual result. It is possible that when changing the opacity texture of the tabs you may encounter an error where the texture fails to load.
First make sure the image is a JPG. If it still does not work, the solution I have found to this problem is to activate the skin editor by clicking Yes in the floating window that appears. When we deactivate the skin editor again the texture will load correctly. Another trick I recommend is to use the eyebrows as 2D models rather than as a texture to prevent the texture from distorting or pixelating when stretched and the cel shading effect will interact better with the 3D face. It is a good idea to use the cartoon eyebrows that Character Creator offers by default and then customize them.
Customize the cartoon character
Now that we have fully tooned the model, it is time to personalize it.
If we go to the Morph section we can find several morphs that will be especially useful in this case. “Head scale” is a great step towards cartooning our character, but “Eyeball scale” and “Eye scale” are also very useful. After a couple more tweaks, we can take it to Zbush to do the rest of the work. As I have said before, I always work in Zbrush without perspective, and I like to visualize the polygons I’m working with so I can more accurately create the models. After modifying the size of the head, the most important thing is to define the height and width of the neck. But it is common for people to forget to adjust the width of the neck in profile resulting in the strange sensation that the profile of the animated character is totally different from its frontal image.
In this case I decided to make a cartoon Nefertiti-style collar. This is the most fun part of the job for me. But remember that you have to constantly look at the sketches and references to not stray from the style and the result you were looking for.
Zbrush also has the option to lower the opacity of the program. Taking a character from my video game The Evil Furry as an example, the slider at the top of the program allows us to customize its opacity. This way, the reference we want to trace can be visible in the background. This is very useful because we tend to deviate from the source like making the eyes too small, the mouth too big, or ears too detailed in relation to the reference.
I then proceed to hide the fleshy parts of the eyes inside the skull to simplify the eyes. Even though I give plenty of mention to the 3D face, the rest of the body should not be neglected, especially the hands. You can and should deform the character as much as necessary to resemble your reference sketch. You may even experiment with form or ideas that may be more appealing to you, but it is generally better to leave the form-finding in the sketching stage since we tend to be more conservative with 3D modeling than drawing.
Character Creator is very versatile in this aspect, coupled with its ability to automatically correct all problems with the rig when the character is brought into the program: just go to the Adjust Bones menu and click on the Auto Position button. We will soon see that the character is fully operational, although in this case, the eyes should be repositioned.
Often, the cel shaded effect does not turn out as expected, so we have to make further modifications so that the outlines also appear on the inside of the character and not just on the edges. Lines are produced on very pronounced angles of the geometry, that’s why the smooth upper part of the nose does not generate lines, but the nostrils are outlined due to sharper angles. We can take advantage of this mechanism by forcing the creation of unique outlines, like placing them on the corners of the lips to heighten expressiveness.
Creating a line to achieve this effect is very simple. You just have to form a very sharp angle at the corners of your mouth as shown in the video. Just be careful not to deform the mouth too much so that there are no problems when opening the mouth properly and take care that no lumps or deformations are visible when rotating the head.
When we are happy with the model and we have checked that it works correctly with cel shading, we can move on to modeling the final part: the teeth.
Fine-tuning the details : Modeling the teeth
Character Creator has cartoon style teeth for these instances which are certainly more suitable than realistic teeth. However, if you look closely, it is rare for a cartoon to have all individual teeth clearly defined. Most of the traditional animated films unify all the teeth, making the final result more pleasant and easier to draw. We don’t want the character looking horrible every time it opens its mouth, so we are going to merge all teeth into one unified mesh.
For this we are going to use Zbrush to hide all the teeth inside the skull because we’ll be using the gums as teeth. As unpleasant as the idea sounds, this is the best method I have found to achieve the same effect as a drawing. By flattening the gums and combining them into a single block, we get a fantastic cel shade effect. Although, of course, you must change the texture to a solid color and remove the normal textures, and the same should be done for the tongue. Meanwhile the teeth should be correctly positioned in the mouth, however, the positioning will be adjusted when creating facial expressions.
Now we’ll finish off with the eyes. Although the art style I’ve chosen does not include glint in the eyes (Disney characters did not have glinting eyes until Bambi was released in 1942), I’ll explain two ways to go about adding them to bring them to life. The first method is to add highlights as part of the drawing, which is the most common way in traditional hand-drawn cartoons on acetate, and produced by hand using digital programs in modern times. Sometimes highlights are added as an after effect that can be repositioned around the surface of the eye as one wishes, but we can do it simply by embedding it within the texture.
While the effect is nice and easy to apply, it is strange that the reflections are not affected by the upper eyelid; we can solve this problem by deploying a the second technique: that is to illuminate the eyes as if there was a light pointed at them (this technique is unusual for 3D animation but can be seen in animations made by Spa Studios). To do this, we add highlights to the “Eye Occlusion” model over the eye. We simply create a JPG image as a layered shell and apply it to the texture. I’ve had issues before with these textures which can be solved by saving the image file and opening them again.
As one can tell, the result is more realistic, but since we can’t move the highlights with the iris, it won’t look good aesthetically.
Tips on Character clothing
In conjunction with all this work, I’ve been making clothes and accessories for the character in Zbrush. I won’t dwell on this process, but here are a couple of tips:
Clothes and hairstyles are the fundamental parts of designing characters, and it’s advisable to design them with clothes they will wear the most, even if we have to imagine the look of their bodies. Design with big and simple shapes so that characters don’t turn into a mishmash of meaningless lines. Same as for the rest of the model, textures should remain solid flat colors and one should check to make sure the cel-shading is working properly. However, don’t stress this part of the process because some tweaks can still be made when the character is exported to Unreal.
I hope you liked this first tutorial; I’ve really wanted to do it for a long time and I’ve put a lot of thought into it. I hope my tips will be a guide for you to create new characters and different styles. See you in the second part!
Learn more :
• Tijerín Art (José Antonio Tijerín) https://www.artstation.com/tijerinart
• Auto Setup for Unreal Engine https://www.reallusion.com/auto-setup/unreal-engine/default.html
• Character Creator https://www.reallusion.com/character-creator/
• iClone https://www.reallusion.com/iclone/
• Reallusion https://www.reallusion.com/