about transparency shader in Unity 6 with Spine 4.2.40 use built-in RP

SsuanLoBeach · 7 दिन पहले

Harald screenshot here

Although it can't be fade in and out, more like cutout, but it's enough for me.

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

Harald · 7 दिन पहले

suanLoBeach Although it can't be fade in and out, more like cutout, but it's enough for me.

Unfortunately I don't understand what you mean by that. Why can't you fade in or out? What is the setup in your screenshot, as it shows some semi-transparent parts and a write rectangle.

Please always describe what you are trying to achieve and what you get instead in as much detail as possible. And when sharing screenshots, please note that we don't know the setup that has led to this screenshot, which objects are placed where (a scene view screenshot helps), which shaders are used where, etc.

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

I just had a look at the Skeleton Lit ZWrite shader, it does not use a depth-pre-pass to ensure only the topmost triangles show through.

So you could use the depth pre pass in your shader like from Spine/Outline/OutlineOnly-ZWrite. Add the following pass

Pass
{
	Name "DepthOnly"

	ZWrite On
	ColorMask 0
	Cull Off

	CGPROGRAM
	#pragma vertex DepthOnlyVertex
	#pragma fragment DepthOnlyFragment
	#include "CGIncludes/Spine-DepthOnlyPass.cginc"
	ENDCG
}

before

Pass {
    Name "Normal"

Otherwise you would need to invert the draw order of your skeleton.

SsuanLoBeach · 7 दिन पहले

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

// code start
Shader "Spine/Skeleton_custom" {
Properties {
_Cutoff ("Shadow alpha cutoff", Range(0,1)) = 0.1
[NoScaleOffset] MainTex ("Main Texture", 2D) = "black" {}
[Toggle(STRAIGHT_ALPHA_INPUT)] _StraightAlphaInput("Straight Alpha Texture", Int) = 0
[HideInInspector] _StencilRef("Stencil Reference", Float) = 1.0
[HideInInspector][Enum(UnityEngine.Rendering.CompareFunction)] _StencilComp("Stencil Comparison", Float) = 8 // Set to Always as default
_AlphaClip ("Alpha Clip Threshold", Range(0.001,0.1)) = 0.01 // Alpha clipping threshold
_AlphaFeathering ("Alpha Feathering", Range(0.001,0.05)) = 0.01 // Controls the feathering range

	// Outline properties are drawn via custom editor.
	[HideInInspector] _OutlineWidth("Outline Width", Range(0,8)) = 3.0
	[HideInInspector][MaterialToggle(_USE_SCREENSPACE_OUTLINE_WIDTH)] _UseScreenSpaceOutlineWidth("Width in Screen Space", Float) = 0
	[HideInInspector] _OutlineColor("Outline Color", Color) = (1,1,0,1)
	[HideInInspector][MaterialToggle(_OUTLINE_FILL_INSIDE)]_Fill("Fill", Float) = 0
	[HideInInspector] _OutlineReferenceTexWidth("Reference Texture Width", Int) = 1024
	[HideInInspector] _ThresholdEnd("Outline Threshold", Range(0,1)) = 0.25
	[HideInInspector] _OutlineSmoothness("Outline Smoothness", Range(0,1)) = 1.0
	[HideInInspector][MaterialToggle(_USE8NEIGHBOURHOOD_ON)] _Use8Neighbourhood("Sample 8 Neighbours", Float) = 1
	[HideInInspector] _OutlineOpaqueAlpha("Opaque Alpha", Range(0,1)) = 1.0
	[HideInInspector] _OutlineMipLevel("Outline Mip Level", Range(0,3)) = 0
}

SubShader {
	Tags { "Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent" "PreviewType"="Plane" }

	Fog { Mode Off }
	Cull Off
	Lighting Off

	Stencil {
		Ref[_StencilRef]
		Comp[_StencilComp]
		Pass Keep
	}

	// Pass 1: Only writes depth, doesn't render color, but uses feathering effect
	Pass {
		Name "DepthOnly"
		ZWrite On
		ColorMask 0
		
		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag
		#include "UnityCG.cginc"
		#include "CGIncludes/Spine-Common.cginc"
		sampler2D _MainTex;
		float _AlphaClip;
		float _AlphaFeathering;

		struct VertexInput {
			float4 vertex : POSITION;
			float2 uv : TEXCOORD0;
			float4 vertexColor : COLOR;
		};

		struct VertexOutput {
			float4 pos : SV_POSITION;
			float2 uv : TEXCOORD0;
			float4 vertexColor : COLOR;
		};

		VertexOutput vert (VertexInput v) {
			VertexOutput o;
			o.pos = UnityObjectToClipPos(v.vertex);
			o.uv = v.uv;
			o.vertexColor = PMAGammaToTargetSpace(v.vertexColor);
			return o;
		}

		float4 frag (VertexOutput i) : SV_Target {
			float4 texColor = tex2D(_MainTex, i.uv);
			#if defined(_STRAIGHT_ALPHA_INPUT)
			texColor.rgb *= texColor.a;
			#endif
			
			 // Calculate final alpha
			float finalAlpha = texColor.a * i.vertexColor.a;
			
			// Use smooth transition instead of hard clipping
			float lowerBound = _AlphaClip - _AlphaFeathering;
			float upperBound = _AlphaClip + _AlphaFeathering;
			
			// If alpha is less than lower bound, discard pixel completely
			if (finalAlpha < lowerBound)
				discard;
			
			// Use smooth transition in boundary area
			if (finalAlpha < upperBound) {
				// Calculate attenuation factor - smooth transition in boundary area
				float t = (finalAlpha - lowerBound) / (2.0 * _AlphaFeathering);
				float alphaFactor = smoothstep(0.0, 1.0, t);
				
				 // Randomly discard some pixels to create feathering effect
				if (alphaFactor < frac(sin(dot(i.uv, float2(12.9898, 78.233))) * 43758.5453))
					discard;
			}
			
			return float4(0, 0, 0, 0); // Do not output color
		}
		ENDCG
	}

	// Pass 2: Renders color, but doesn't write to depth
	Pass {
		Name "Normal"
		ZWrite Off
		Blend One OneMinusSrcAlpha
		
		CGPROGRAM
		#pragma shader_feature _ _STRAIGHT_ALPHA_INPUT
		#pragma vertex vert
		#pragma fragment frag
		#include "UnityCG.cginc"
		#include "CGIncludes/Spine-Common.cginc"
		sampler2D _MainTex;
		float _AlphaClip;

		struct VertexInput {
			float4 vertex : POSITION;
			float2 uv : TEXCOORD0;
			float4 vertexColor : COLOR;
		};

		struct VertexOutput {
			float4 pos : SV_POSITION;
			float2 uv : TEXCOORD0;
			float4 vertexColor : COLOR;
		};

		VertexOutput vert (VertexInput v) {
			VertexOutput o;
			o.pos = UnityObjectToClipPos(v.vertex);
			o.uv = v.uv;
			o.vertexColor = PMAGammaToTargetSpace(v.vertexColor);
			return o;
		}

		float4 frag (VertexOutput i) : SV_Target {
			float4 texColor = tex2D(_MainTex, i.uv);

			#if defined(_STRAIGHT_ALPHA_INPUT)
			texColor.rgb *= texColor.a;
			#endif

			// Keep alpha test consistent
			float finalAlpha = texColor.a * i.vertexColor.a;
			clip(finalAlpha - _AlphaClip);

			return (texColor * i.vertexColor);
		}
		ENDCG
	}

	// Caster Pass (unchanged)
	Pass {
		Name "Caster"
		Tags { "LightMode"="ShadowCaster" }
		Offset 1, 1
		ZWrite On
		ZTest LEqual

		Fog { Mode Off }
		Cull Off
		Lighting Off

		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag
		#pragma multi_compile_shadowcaster
		#pragma fragmentoption ARB_precision_hint_fastest
		#include "UnityCG.cginc"
		sampler2D _MainTex;
		fixed _Cutoff;

		struct VertexOutput {
			V2F_SHADOW_CASTER;
			float4 uvAndAlpha : TEXCOORD1;
		};

		VertexOutput vert (appdata_base v, float4 vertexColor : COLOR) {
			VertexOutput o;
			o.uvAndAlpha = v.texcoord;
			o.uvAndAlpha.a = vertexColor.a;
			TRANSFER_SHADOW_CASTER(o)
			return o;
		}

		float4 frag (VertexOutput i) : SV_Target {
			fixed4 texcol = tex2D(_MainTex, i.uvAndAlpha.xy);
			clip(texcol.a * i.uvAndAlpha.a - _Cutoff);
			SHADOW_CASTER_FRAGMENT(i)
		}
		ENDCG
	}
}
CustomEditor "SpineShaderWithOutlineGUI"

}

SsuanLoBeach · 7 दिन पहले

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

Harald · 7 दिन पहले

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 .

SsuanLoBeach · 7 दिन पहले

Harald

Harald 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.

Because my texture is made by the ink flow diffusion drawing method, there will be many places with high transparency. If I don't use dither, the top model will have many very transparent areas that block the objects behind. Visually, it looks like it is blocked by air. For example, the trunk of the tree in my screenshot. If I don't use dither, part of the outer side of the trunk will also block the objects behind.

Harald · 7 दिन पहले

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.

SsuanLoBeach · 6 दिन पहले

Harald Can I do that on many texture in a same skeleton ?
different mesh, different texture, like those leaf, in the same skeleton

Harald · 6 दिन पहले

@suanLoBeach Yes.

SsuanLoBeach · 6 दिन पहले

Harald How to do it ? the texture have the same Z value, they are on a same plane

Harald · 6 दिन पहले

@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.

SsuanLoBeach · 6 दिन पहले

Harald oh, it's what i need ,thx

I have another quastion, I wanna leaf is dynamic by vertex displacement,but stem is static, now they use the same material , so How can I make two different affect, 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 ?

Harald · 3 दिन पहले

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.

SsuanLoBeach · 3 दिन पहले

Harald So the step of customizing the materials of multiple components is done in Unity? Is there anything I need to do in Spine?

SsuanLoBeach · 3 दिन पहले

Harald I have know how to set custom material for any slot, thanks

Harald · 3 दिन पहले

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