You can watch the entire workflow through the video.

Before We Begin

Backlight refers to when the light source is behind the subject.

When drawing illustrations, the difficult part is plausibly calculating the areas of light and shadow on complex objects (like character figures).

I'd like to introduce tips for drawing backlit illustrations using CLIP STUDIO's 3D materials.

For this example, I'll be drawing a character with their back to a window. I've conceptualized a rough sketch of an atmospheric illustration where a character facing away from a window receives backlight.

Next, let's roughly set the direction of light for this illustration.

It's convenient to draw a sphere next to it to clearly indicate the light direction.

Importing 3D Models

Import a head model from 3D materials.

The menu path is Assets > 3D > Head.

After adding it, set the direction of the 3D model to match the illustration you want to draw.

3D materials can be manipulated in size and position using handles. Let's adjust it to align with the rough sketch you've drawn.

Setting Up the 3D Model

Now, let's reflect the light and shadow settings we made on the sphere onto the 3D model.

There are two main areas to adjust.

Light Source Position and Intensity

In the light source tab, you can drag the sphere to change the direction of the light source. Adjust the light source's position by referring to the sphere you drew in the rough sketch.

 

You can also adjust the intensity of both parallel light and ambient light so that it's not too bright or too dark.

Understanding parallel light as the intensity of the main light and ambient light as the overall brightness of the object will make it easy to adjust.

 

 

Change Light Source Rendering Method to 'Toon'

In the Environment tab, under Rendering Settings > Lighting, check 'Influence of light source' and change the method to 'Toon'.

This is to see areas composed of two tones, light and shadow, rather than soft shadows.

This is the appearance of the 3D model created in this way.

Rasterizing and Binarizing the 3D Model Layer

This 3D model will be used as a shadow layer. While it's fine as is, let's adjust it a bit more.

Rasterize the 3D model layer. Apply 'Rasterize' from the Layer menu.

After that, binarize the rasterized layer using the edit properties.

The binarization menu is located in the top menu under Edit > Tonal Correction > Binarization...

Adjust the binarization threshold appropriately.

As you can see from the result, a layer consisting of two tones, light and dark, has been created.

This layer will be used as a shadow layer after the line art is done.

Temporarily lower the opacity of the layer and proceed with the next step.

Line Art and Base Color Work

Draw the line art for the illustration and fill it with a single color.

I've worked on an illustration of a long-haired female character like this.

While you could use the 3D model layer created earlier only as a reference to define the light and shadow in the illustration, this time I'll try to work more easily.

 

 

Creating a Shadow Layer

Now, clip the shadow layer we created earlier to the base color layer, then change its blending mode to Multiply.

 

 

In this state, there are areas in parts like the hair and ears that don't align with the lines. Refer to the original shadow shape and refine the shadow's form to match the lines.

This is how the shadow looks after refining its shape and changing its color to match the atmosphere. If you add the illustration's colors and background, it will look like this.

Detailing

The basic shape of the illustration is now established. Now, adding detailed descriptions will complete it.

Adding Rim Light to Dark Areas

If the shadows are too dark, you can slightly adjust the brightness of the drawing with reflected light (rim light). The important thing to note is that reflected light should not be brighter than the main light source.

Adding an Add (Glow) Layer

If you want to express an atmospheric backlight, it's good to use an Add (Glow) layer. Painting the parts that receive light can create an even more impactful backlit effect.

Completion

Here is the final completed illustration.

Utilizing 3D assets can be applied not only to backlit illustrations but also to lighting in various positions.

I hope this article was helpful, and I wish everyone happy illustrating! :D