How to draw anime backgrounds in 3D space with 3DCoat by nyorock

[Carlosan]

Source...

In this article, I would like to introduce mainly "How to draw anime backgrounds in 3D space with 3DCoat"
rather than "What is 3DCoat?" Specifically, it will be a simple making article of what I introduced in the tweet below. The method is still in the process of trial and error, but I would appreciate it if you could get interested in 3DCoat and animation background style expressions, saying, "You can do this with this tool."

Using 3DCoat, I tried to create an anime background style expression like this

 

Introduction of the creation process

3DCoat is a very versatile and highly functional tool, but it seems to be a tool that is not widely known because there is little information in Japanese. It's a tool with a somewhat unique feel, and I see it being said to be a difficult tool to master.

I've been using 3DCoat for about 10 years, but I still don't fully understand how to use it. However, it is a tool with a mysterious charm, and I have the impression that there are many people who are trying to master it. I am also obsessed with its charm, and I am doing trial and error to see if I can make good use of it even though I do not understand it.
Under such circumstances, I would like to introduce the unique functions that I verified this time.
In the following, we will introduce the functions used along the flow of the creation process of the verification example.

 

Preliminary work

This is the start screen that appears when you start 3D Coat. It seems that it can be used in various ways depending on the application. This time, we will do "Voxel sculpting".

 

I'll start with an empty state for now.

This is the work screen of 3DCoat. Basic UI for voxel sculpting.

 

Voxel tool

This time, I mainly used the brush tool "Sphere" of "Voxel Tool". (I will omit the explanation about "Voxel".)

 

It looks like creating a voxel with the "sphere" brush tool. This is the basic behavior of the "sphere" brush.

With this kind of feeling, you can draw directly with voxels in an empty space. Here, I draw using pen pressure sensitivity using a board tablet. You can draw in 3D space with behavior similar to the brush tool of the 2D paint tool

 

What I used this time is a function that allows you to draw while coloring the voxels. It seems to be a function of the latest version of 3DCoat2022. 3DCoat often has new features added without knowing much information. You can use it by checking the "Colored voxels" item in the brush tool options.

 

Then you will be able to draw freely in 3D space with colors like this. This seems to be something that 3DCoat couldn't do until recently. It may be a natural function for VR painting tools, but I was surprised that "3D Coat has such a function!"

 

For example, you can prepare a large sphere as a base like this and draw along it. Also, by adjusting the brush settings, it is possible to make the brush behave like scattering small spheres at random. In 2D paint tools such as Photoshop, settings similar to the familiar scatter brush settings are also possible.

 

Created in color only

 

This time, as a method to express the background style of anime, I decided to "paint by hand as a picture" for each shadow and texture. Switch the viewport display to a "color only" display without shading (no smooth shading). Then, it will simply display only the color, so I will choose the color myself and draw the leaves just like I usually draw a background image.

I adjust the size of the brush and sometimes pull it with the move tool, just like drawing. It is necessary to draw in 3D space while rotating the screen so that it can be viewed from any angle, which is quite difficult and is still in the process of trial and error. 3DCoat also has a 3D paint function, so you can simply paint with a brush or blend it with the "blur" tool. Voxel sculpting and 3D painting are done simultaneously and alternately to finish.
 

It is a supplement about the characteristics of animation background image expression. There are various styles in the actual work, even though it is an animation background style expression, but I feel that one characteristic that is common to some extent is "expressing a three-dimensional effect and space by overlapping surfaces". The figure above is an attempt to explain its features. I will draw while being aware of the characteristics of such anime background style expressions.

[Carlosan]

Here it is once completed.

I don't know the detailed painting mechanism, but it seems that the vertex color painting to the voxel is done instead of the texture painting to the UV-expanded polygon object.

A large number of vertices are required to create a detailed leaf shape and to paint neatly with vertex colors. Therefore, the problem with this method is that the 3D data becomes quite heavy. If you return the view display to the display with shading, you can see that the model is a fairly high mesh.

 

Using the above functions, I tried to create an anime background style shrub. The ground was also easily created using the same method.
Finally, I tried to finish it as follows.

Finished product

 

 

Export method

Regarding the export after completing the work with 3DCoat.
In order to take it to some other 3DCG tool and use it, it needs to be exported in some way.
I'm still verifying how it can be used, but I will introduce the export method I tried this time.

 

First, switch the UI from "Voxel Room" to "Paint Room". Then select "Export Model" from the Paint Room's File menu. * It seems that the type of export menu differs depending on the UI. This time I exported from the paint room.

 

On export, a conversion from voxels to polygons is done. Polygon reduction can be performed at that time. If you reduce the number of polygons, the data will be lighter, but the detail will be lost. This time I exported it as it is without reducing it. It will be exported in obj format.
 

This is the exported obj data read by Cinema4D. Since the vertex color paint information was retained as it was, the color was reflected immediately after loading on Cinema4D.

 

This is also read by blender. For some reason, when blender directly reads the obj data from 3DCoat, the vertex color information is lost. So, when I read it once with Cinema4D, exported it with FBX, and then read it with blender, the vertex color was successfully reflected.

 

This is what I tried to load into UE5. There were millions of polygons in one object, but thanks to the use of UE5's Nanite function, the display was light even if many copies were made.

 

We are still verifying the handling after export, but it seems that we can bring the vertex color information to other tools as it is. After creating with 3DCoat, I can add more with blender's grease pencil, and it seems that I can place a lot on UE5, so I felt that the possibilities of expression would expand further.

 

In conclusion

This time, I tried the function of "Colored voxels" which is a new function of 3DCoat for the first time.
I had the impression that the 3DCG expression in the usual polygon modeling tends to be hard, but the 3DCoat voxel sculpting I tried this time was able to create a softer, more painterly expression than I expected.
The method is still in the process of trial and error, but I felt the possibility of using it for animation background style expression.
Also, I was able to simplify the workflow part considerably, so I felt that it was a friendly method for 2D painting.

 

In the conventional asset creation procedure, it was necessary to go through a complicated and confusing procedure of
"sculpting -> retopo -> UV development -> texture baking -> material settings -> rendering settings" .

In this method, "simultaneous work of voxel sculpting and 3D painting → export and set vertex color" is almost the end, so it was very simple and easy.

However, there are many problems and restrictions at present, such as ``it is difficult to draw in the desired shape'', ``the number of polygons is too large'', ``3DCoat functions are unstable'', and ``vertex colors are harder to handle than textures''.

However, it was a fun verification that felt various possibilities.

I have the impression that 3DCoat is not a tool that can be recommended to everyone, but it has some unique features that you won't find anywhere else, so I think it's a very interesting tool to try out.

I hope this introductory article has piqued your interest in 3DCoat.

 

Thank you very much.