Using the Perspective Ruler and 3D Models to Draw Backgrounds
To learn the basics of the perspective ruler, read the following TIPS article.
[1] Why should you use the perspective ruler with 3D models?
・ Weaknesses of the perspective ruler
Perspective is used to draw horizontal and vertical lines and lines going into the distance to create a three-dimensional effect.
You can use the perspective ruler to draw 3D shapes such as cubes.
When drawing with perspective, you can only draw horizontal and vertical lines.
You cannot use the perspective ruler to draw lines that are neither horizontal nor vertical, like the roofs of buildings for example.
To draw slanted lines, you need to create a new vanishing point.
・ Difficulty of making vanishing points for slanted lines
There are several ways of finding the vanishing point of a slanted line, but all of them are quite time-consuming.
However, with CLIP STUDIO PAINT’s 3D model features, you can rotate 3D objects to quickly and accurately make a perspective ruler for slanted lines.
For example, if you want to add an angled staircase to this apartment building, you can rotate a 3D shape to work out the vanishing point.
You can import and rotate the shape, then use it to add guide lines for the vanishing point.
Then, use the perspective ruler grid to easily draw steps at the appropriate intervals.
This method is very useful when you need to accurately draw with perspective. In this lesson, I’ll explain the method step-by-step.
Hint:
The “measuring point method” can also be used to accurately draw slanted lines. However, this method is quite complex, as you need to make several guide lines to find the measuring points. I won’t explain this method in this lesson, but you can read up on it to understand perspective better.
If you don’t fully understand it, you can use 3D tools to make this complex process a bit easier.
After you’ve used the tools in CLIP STUDIO PAINT and can understand perspective a bit more instinctively, you may then find that you understand the measuring point method.
[2] Using 3D models to create a perspective ruler
■1. Import a model
You can find 3D objects in CLIP STUDIO ASSETS. They are free to download, so I’m using one of these in this example.
This 3D model will help me to draw the slanted lines.
First, import your 3D model. I add this cube by dragging it from the [Material] palette onto the canvas.
After adding a 3D model, the tool automatically switches to the [Object] tool.
■2. Adjusting the 3D camera
Let’s adjust it so we can see the cube from the right angle. First, I’ll explain how to adjust the camera.
You can adjust the angle like a cameraman walking around the 3D object and zooming in or out.
Changing the camera angle does not rotate or move the 3D object itself.
Select the icon for moving the camera forwards and backwards, then drag up and down in the empty space around the object to make it look smaller or bigger.
Note: You can also do this by dragging up and down while holding the right mouse button.
It’s easier to adjust the 3D model when the camera is zoomed out to make it look smaller.
Now select the icon for rotating the camera, and drag on the canvas to rotate.
A grid displays on the ground when you drag the cursor, making it easy to check whether the camera is at a high or low angle.
Note: You can also do this by dragging up and down while holding the left mouse button.
Note: Take care not to drag the 3D object.
■3. Show the perspective ruler
The ruler icon will be shown on the layer that was created when you imported the 3D model.
The ruler is hidden when you first import the 3D model. You can toggle the perspective ruler display on and off by holding the Shift key and clicking the ruler icon.
■4. Temporarily hide the 3D model
The 3D model can get in the way when drawing, so hide it by going to the [Object] tool > [Tool Property] > [3D object], and clicking the eye icon beside the object name.
You can also adjust the perspective ruler in the [Tool Property] under [Angle] > [Perspective]. The larger the value, the closer the vanishing point and the greater the sense of depth. It changes in proportion to the size of the canvas.
[3] Rotate the 3D model and draw the slanted lines
(1) Use the base vanishing points to draw the vertical and horizontal lines
Make a new layer for drawing and draw the vertical and horizontal lines using the vanishing point you chose. I use the perspective ruler by toggling snap to special ruler on and off.
Next I’m going to add slanted lines for the roof to this cube. The red and blue lines will each need their own vanishing points. We’ll use the 3D cube created earlier to help.
(2) Display the 3D model
I’ll use the 3D model to help me draw the slanted lines.
I select the layer with the 3D object and go to the [Object] tool > [Tool Property] > [3D object] and click beside the object name to display it again.
(3) Rotate the angle of the 3D model
I rotate the 3D model. This time, make sure you don’t change the camera angle but the 3D object itself.
You can rotate the object by going to the [Sub Tool Detail] palette > [Allocate] and adjusting the parameters under [Rotate].
In this case, I set the X axis to 30.
Hint:
Clicking a 3D model with the [Object] tool will display the manipulator. In this case, I want to set the object to a precise angle using numerical values, so I use the [Sub Tool Detail] palette.
(4) Make the perspective ruler for slanted lines on a new layer
Let’s make the perspective ruler for the slanted lines on a new layer. Use the rotated cube to add a vanishing point.
(5) Add another angled line.
I rotate the cube again using the [Sub Tool Detail] palette and change the X axis value to 60.
(6) Add another vanishing point
I add another vanishing point using the rotated cube.
(7) Draw lines using the slanted vanishing points
I use the new perspective ruler to draw lines for the slanted roof.
(8) Draw the remaining lines using the original perspective ruler
Using the perspective ruler that was made when I first imported the 3D model, I draw the last line. That’s all for this basic method of drawing slanted lines using 3D models.
[4] Making a perspective ruler with a 3D model based on a draft or photo
(1) Prepare the photograph or sketch
We can make a perspective ruler with a 3D model when the angle is already decided with an existing draft or photo.
(2) Paste the 3D model
I add this 3D model of a cube onto the canvas.
(3) Switch between the object and ruler on the layer
I check the layer that the 3D model was imported to. The 3D icon and the ruler icon will both be shown on the layer thumbnail. To start with, I display the ruler.
With the [Object] tool, click the Ruler icon on the 3D model layer to adjust the vanishing points of the ruler. Move the guide lines to match up the vanishing points of the perspective ruler with the draft or photo.
Hint:
You can adjust the angle of pasted 3D models by adjusting the perspective ruler. To do this, select the ruler with the [Object] tool (so that the handles are visible on the ruler), then right-click the ruler to show the pop-up menu, and turn off [Fix eye level].
I recommend turning off [Fix eye level] when you are using a photo or draft.
Click the 3D object icon on the layer to operate the 3D model. Then, rotate the cube to use it for drawing.
You can also rotate and move the 3D model according to the vanishing points set in the perspective ruler.
You can accurately draw slanted lines, such as for staircases, by setting the angle with a 3D cube.
I rotate the cube while considering what angle I want for the staircase.
I make a perspective ruler on a new layer using the tilted cube.
In this case, I want to add steps on the staircase, so I adjust all three vanishing points using the cube.
I select the ruler using the [Object] tool, then go to the [Tool Property] palette and turn on the [Grid]. In this example, I turn on the [XY plane].
I adjust the grid size so that I can use it to draw the stairs.
I draw the stairs at intervals while switching between the perspective ruler.
Now I’ve finished drawing this part.
・ Artist profile: Hey!TAROH
Hey!TAROH has been using digital art software since the very first release of Manga Studio Ver 1. He is a writer for the official guides and references for Manga Studio and Clip Studio Paint. He draws several manga comics and looks after his household.
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