Precautions when creating models using Cubism 5.3 new features
Updated: 01/19/2026
The “Blend mode” and “Offscreen drawing” features introduced in Cubism 5.3 are new features that significantly enhance model expressiveness,
but they impose a higher drawing load compared to previous features. “Expressiveness” and “load” are two sides of the same coin, and it is necessary to use these features whileunderstanding the drawing load.
Here, we will explain the points that can contribute to the “load” and the precautions that should be taken when creating models.
Blend mode
Models using the new advanced blend modes*1 added in Cubism 5.3 will have a higher rendering load than blend modes up to 5.2, which will affect the frame rate (fps).
*1 “Advanced blending modes” refers to color blending modes other than “Normal,” “Add (5.2 and earlier),” and “Multiply (5.2 and earlier),” and alpha blending modes other than “Over.”
*For details on the Blend mode feature, please see “Blend mode“.
Types of Blend modes
There is little difference in drawing load depending on the type of advanced Blend mode.
Number and size of ArtMeshes
The more ArtMeshes that use advanced Blend modes, the greater the rendering load, which affects the frame rate. Exercise caution when using them frequently.
There is no difference in drawing cost based on the size of the ArtMesh.
Offscreen drawing
Models with parts that use Offscreen drawing affect performance compared to models that do not use it.
The performance in this context is related to two factors: “drawing load” and “memory usage”.
There are the following two points concerning how Offscreen drawing impacts performance.
| ① | Caused by the model’s use of Offscreen drawing (determined at the time of model creation) |
| ② | Factors attributable to the runtime environment in which the model operates (Varies depending on the operating environment) |
* For details on the Offscreen drawing feature, see “Offscreen drawing“.
Number of Parts
It corresponds to ①.
As the number of Offscreen drawing operations increases, the drawing load increases, affecting the frame rate.
Please be cautious about excessive use. Additionally, depending on the model structure, memory usage may increase significantly.
Structure of the Model
When using Offscreen drawing, memory usage is determined by the number used and the maximum depth in the parent-child hierarchy.
Models structured such that the parent-child hierarchy of parts using Offscreen drawing becomes deeper will consequently result in increased memory usage.
However, if Offscreen drawing instances exist in parallel at the same hierarchy level, memory usage is reduced compared to models with a deep parent-child hierarchy structure, even when the number used is the same.
For models where these elements are combined, it is advisable to leverage the model structure effectively, as shown below.
Instead of deepening a single hierarchy and using Offscreen drawing for each layer, you can reduce memory usage by keeping the hierarchy as shallow as possible and placing parts that can share the same hierarchy within that level.
Tips
Keep the use of Offscreen drawing to the minimum necessary, following the principle of ‘handling parts that can be parallelized in parallel, and only increasing complexity for absolutely necessary parts.’
Part size
It corresponds to ①.
The size of an Art Mesh that is a child of a Part set with Offscreen drawing does not affect performance.
Regardless of whether Offscreen drawing is enabled or not, the drawing of the child Art Mesh occurs only once, because there is no difference whether the drawing destination is offscreen or the display screen.
Size of the area used to draw the model
It corresponds to ②.
Offscreen drawing is generally created and rendered to match the size of the area where the model is actually drawn.
This size is unified based on the model’s drawing area, irrespective of the size of the child ArtMesh being drawn offscreen. Consequently, if the size of the area used to draw the model within the software increases, memory usage increases proportionally.
At the same time, the rendering burden increases, which negatively impacts the frame rate.
Furthermore, when Offscreen drawing is frequently used for small ArtMeshes, phenomena such as “a high drawing cost relative to the displayed size” occur, so care must be taken regarding where it is used. Note that the size of the model’s canvas or the size of the texture atlas does not affect this here.
Comparison of the load of Blend mode and Offscreen drawing
The drawing load ranking of each feature is as follows.
(Heavy) Offscreen drawing > Advanced Blend modes (≒ Clipping) >> Normal Blend modes (Light)
Check statistics for Blend Mode and Offscreen Drawing
Since Cubism Editor 5.3.00 beta4, statistics such as the “Usage count of advanced blend modes” and information related to “Offscreen drawing” can be checked in the model statistics.
| Model Statistics | Cubism Viewer (for OW) |
 |  |
Checking Operation
Models that use either the Blend mode or Offscreen drawing features are affected in terms of performance by the specifications of the PC displaying the Live2D model, and the actual screen size (screen resolution) used by the software for display. The larger the screen size, the greater the impact on performance.
Tips
When verifying the model’s operation, be sure to display the actual model and confirm its behavior in the environment where software that displays the model, such as nizima LIVE, is running.
Summary
When creating models that use Blend mode and Offscreen drawing, start by considering which environment the model will operate in, and create a model that operates in the most constrained environment among those options.
Key considerations when actually creating a model are as follows.
Notes (1)
Adjust the number of uses for Blend mode and Offscreen drawing.
If performance is sluggish when displaying or animating the model, you need to refer to the model’s statistics and reduce the following counts.。
・Number of objects using advanced Blend mode.
・The number of parts with Offscreen drawing.
Notes (2)
Adjust the hierarchical structure when utilizing Offscreen drawing.
When deep parent-child hierarchies that utilize Offscreen drawing are implemented, memory usage increases according to the maximum depth and the number of elements utilized.
If displaying the model in the actual rendering environment consumes excessive memory, it is necessary to reduce the depth of parent-child hierarchies that utilize Offscreen drawing, while referencing the model statistics and the parts palette.
Other notes
A higher resolution for displaying the model proportionally impacts the “rendering load” and “memory usage.” In the expected environment, make sure to adjust Notes (1) and (2) as needed.
It is important to display and verify the actual models beforehand in the environment where these models are rendered.
Sample data for load verification
We have prepared a verification model incorporating Blend mode and Offscreen drawing. You can check the load in the actual environment where the model is displayed.
Sample data can be downloaded here.
※Please be sure to check the ‘Free Material License Agreement‘ before downloading.
