Dynamic Batching not compatible with UI elements? 5.6

Unity Engine
1

I’m currently using the frame debugger and trying to achieve 3 batches in the following scene, as far as i understand it should be possible.

The hierarchy looks like this:

  • Main Canvas ( with RawImage as background, custom material, color (255, 255, 255, 255), raycast off)
  • Panel
  • Button ( RawImage as frame for raycast target, custom material, color (255, 255, 255, 0), raycast on)
  • Icon ( RawImage as button icon with some padding, custom material, color (255, 255, 255, 255), raycast off)
  • Button " same …
  • Icon " same …
  • Button …
  • Icon …
  • Button …
  • Icon …
  • Button …
  • Icon …

With this i’m getting 1 SetPass Call which i suppose is optimized but i’m getting 7 batches.

Looking at the frame debugger shows this:

background 1 batch (not in texture atlas)
5 transparent button raw images 1 batch only (no texture, not in atlas)
but here comes the thing, each icon raw image 1 batch individually (¿ignoring atlas?)

= 7 batches in total

Icons sprites settings:

3031688--226797--texture_settings.png
3031688--226797--texture_settings.png474×579 28.2 KB

Sprites are JPG 128x128.
Dynamic Batching is enabled in Player Settings.
Rendering Path Forward.
Canvas Screen Space - Overlay.
No lights in scene.

Material Shader:

Shader "SimpleUI" {
    Properties
    {
        [PerRendererData] _MainTex ("Sprite Texture", 2D) = "white" {}
        _Color ("Tint", Color) = (1, 1, 1, 1)
    }

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

        Cull Off
        Lighting Off
        ZWrite Off
        ZTest [unity_GUIZTestMode]
        Blend SrcAlpha OneMinusSrcAlpha

        Pass
        {
        CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"
            #include "UnityUI.cginc"

              fixed4 _Color;
            fixed4 _TextureSampleAdd;
  
            struct appdata_t
            {
                float4 vertex   : POSITION;
                float4 color    : COLOR;
                float2 texcoord : TEXCOORD0;
            };

            struct v2f
            {
                float4 vertex   : SV_POSITION;
                fixed4 color    : COLOR;
                half2 texcoord  : TEXCOORD0;
                float4 worldPosition : TEXCOORD1;
            };
  
 

            v2f vert(appdata_t IN)
            {
                v2f OUT;
                OUT.worldPosition = IN.vertex;
                OUT.vertex = UnityObjectToClipPos(OUT.worldPosition);

                OUT.texcoord = IN.texcoord;
      
                #ifdef UNITY_HALF_TEXEL_OFFSET
                OUT.vertex.xy += (_ScreenParams.zw-1.0)*float2(-1,1);
                #endif
      
                OUT.color = IN.color * _Color;
                return OUT;
            }

            sampler2D _MainTex;
            fixed4 frag(v2f IN) : SV_Target
            {
                return (tex2D(_MainTex, IN.texcoord) + _TextureSampleAdd) * IN.color;
            }
        ENDCG
        }
    }
}

EDIT:

Interestingly using the same sprite ( part of the atlas ) in all icons raw images is getting me the desired 3 batches in the exposed scene.

I’m lost :eyes:, why is not working with separated sprites in the same atlas?

2

Alright this Dynamic Batching seems to only work with sprite renderes, which lets me wondering is this technique not aplicable to UI elements?

If so, do i have alternatives?