Performance test of Shape Morphing in Unity

1. Unity Morph
Performance Test

2. To test out BlendShape Performance
In Unity
Objective:

3. For a Start
It is a common practice to split out model into pieces for
various reasons.
For Blendshape, it is to split out specific parts that can get
animated.

4. The Problem
Splitting mesh will result in increase
drawCalls.
As such, it is also a common practice to
limit the number of mesh to as few as
possible

5. Experiment
This experiment will test the performance
between blendshape with splitted and
combined mesh.

6. Sample1
Has 1 unified Mesh, around 40k tri

7. Sample2
Got the mesh splitted.
Part with BlendShape has 6.5k tri

8. Script
A simple Script that will oscillate Blend
value from 0->100

9. Result1
Sample1 Sample2
……No noticeable differences……

10. Sample1 Sample2
Beside increase Draw Calls,
Result2
……No noticeable differences……

11. This isn’t going to be an experiment
Let’s increase morphing Layer to 15

12. Script
This will oscillate all 15 Layers

13. Result1
Sample1 Sample2
……No noticeable differences……

14. Sample1 Sample2
Beside increase Draw Calls,
Result2
……No noticeable differences……

15. What else can we test?
Unity can only support up to 60k tri per
model.
Maxing it out won’t likely to cause any
differences.
Let’s add some animation to the Character.

16. Squiggly random Loop Animation Added

17. It’s pretty much the same thing,
So I’m not going to bother
repost the image
Result……

18. On the other hand……
Unity’s performance is rather well even
when animating a 40k tri character

19. Let’s do one final test
Split the Mesh to 7 parts,
each with a 5 morph Layers

20. Script
This will oscillate each of the Mesh

21. There’s a non-consequential
Result1
apparent increase in performance cost

22. Result2
Draw call increased as expected

23. Seam between meshes
A side note,
won’t appear in Toon Shader

24. In conclusion,
Performance cost is so insignificances to
worry about which method to use.