When you open the texture tab on each editing screen (face, hair etc.) the divided camera panels are displayed on both sides of the screen. The left panel on which the 3D model is displayed is World mode, the right side with the development diagram is UV mode.
In VRoid Studio, you can draw on either the left or right panel, but you can specify whether to draw based on UV or World. Please select UV or world in " Size Space" in the property panel on the right side of the screen.
▼ World mode
When "World" is selected in the size space, the model on the left side is set as the reference. When drawing with a brush, the thickness of the line becomes uniform in World mode, while thickness in UV mode varies throughout the development diagram.
▼UV mode
When "UV" is selected in the size space, the model on the right side is set as the reference. When drawing with a brush, the thickness of the line becomes uniform in UV mode, while thickness in World mode varies according to the surface of the 3D model.
Whether you draw on the left or on the right panel, the line of the reference mode is made even.