suanLoBeach sorry to foget to post my code, I add these codes into spine/skeleton shader

Thanks for the update. Reading your code and looking at the screenshot again now explains why the border looked as it is, I was wondering if you had some compression artifacts leading to the dot-pattern.

I wonder why you are using dither-style feathering though, as a standard threshold might look better with typical the image outlines, which are just a gradient alpha. The purpose of dither patterns is usually where a homogenous area needs to become transparent, there you can't solve it with a single tweaked threshold. If you know what you're doing it's fine of couse, you might have your reasons.

suanLoBeach well, I just wanna ask , Can the perfect feature be achived ? (only show the top transparent pixel)

Perfect alpha blending showing the same result as a render texture would: no, as I said above multiple times. Otherwise we would have provided it in the example scenes instead of the render texture component.

suanLoBeach I'm migranting my project to Godot, So, I'm waitting Godot4.4 runtime, i'll solve this problem in Godot again.

Good luck with the migration. Note however that the problem will not change in the slightest .

suanLoBeach If I don't use dither, the top model will have many very transparent areas that block the objects behind.

Not if you set the _AlphaClip threshold properly to exclude these areas of high transparency. You receive jagged outines instead then, obviously.

@suanLoBeach Yes.

@suanLoBeach Set Advanced - Z-Spacing at the SkeletonAnimation component.
https://esotericsoftware.com/spine-unity-main-components#Setting-Advanced-Parameters
You likely want to set this parameter to a value other than 0.0 whenever writing to the Z buffer.

suanLoBeach I'll add teh code about vertex displacement into my custom spine shader, but there is only one material slot here, do i need to make two slot in spine and how to make it ?

I'm not sure which Material slot you're talking about, but if you want different materials for different slots, see the SkeletonRendererCustomMaterials component.

In general please always check out the spine-unity documentation pages first and the example scenes that come with the spine-unity runtime. For common tasks there is almost always an entry in the documentation or example scene available.

suanLoBeach Glad to hear you've figured it out, thanks for getting back to us.