Shader Trouble Shotting - zzragida/UnityDocs GitHub Wiki

Issue 1. Compilation Failure BloomOptimized Effect

• Device: Nexus 5
• GPU : Adreno 330

메세지

11-04 13:15:23.520 21792 21899 D Unity : GLES: Const arrays detected in a shader, these will crash Adreno 3xx shader compiler. Failing compilation. 11-04 13:15:23.520 21792 21899 D Unity : Note: Creation of internal variant of shader 'Hidden/FastBloom' failed.

상세내용

• Standard Asset의 BloomOptimzed Image Effect를 Camera에 적용

• BloomOptimzed에 사용중인 Hidden/FastBloom.shader가 애플리케이션 실행시점에 에러가 발생함

• 원인

  • Qualcomm Adreno Shader 컴파일러가 셰이더 코드를 최적화할때 Const Array를 컴파일하지 못하는 상황임
  • 예시) static const half4 curve4[7] = { half4(0,0,0,0), half4(1,1,1,1) ...};

• 해결과정

  • Unity에서 해당 셰이더를 OpenGLES Core로 컴파일해서 컴파일된 코드를 분석해 봄
  • 다행히 유니티에서 // XXX ADRENOCONSTARRAYBUG <= 이런 주석을 남겨줌

• 해결책

• Const Array로 접근해서 사용되던 Loop 코드를 수정함

// Before: Adreno Const Array Bug
static const half4 curve4[7] = { half4(0.0205,0.0205,0.0205,0),
                                 half4(0.0855,0.0855,0.0855,0),
                                 half4(0.232,0.232,0.232,0),
                                 half4(0.324,0.324,0.324,1),
                                 half4(0.232,0.232,0.232,0),
                                 half4(0.0855,0.0855,0.0855,0),
                                 half4(0.0205,0.0205,0.0205,0) };
 
void func()
{
  // ...
  for( int l = 0; l < 7; l++ ) 
  {  
    half4 tap = tex2D(_MainTex, coords);
    half4 temp = curve4[l];
    color += tap * temp;
    coords += netFilterWidth;
  }
}
 
 
// After : Adreno Const Array Bug Fix
static const half4 curve4_0 = half4(0.0205, 0.0205, 0.0205, 0);
static const half4 curve4_1 = half4(0.0855, 0.0855, 0.0855, 0);
static const half4 curve4_2 = half4(0.232, 0.232, 0.232, 0);
static const half4 curve4_3 = half4(0.324, 0.324, 0.324, 1);
static const half4 curve4_4 = half4(0.232, 0.232, 0.232, 0);
static const half4 curve4_5 = half4(0.0855, 0.0855, 0.0855, 0);
static const half4 curve4_6 = half4(0.0205, 0.0205, 0.0205, 0);
 
half4 color = 0;
half4 tap = tex2D(_MainTex, coords);
color += tap * curve4_0;
coords += netFilterWidth;
tap = tex2D(_MainTex, coords);
color += tap * curve4_1;
coords += netFilterWidth;
tap = tex2D(_MainTex, coords);
color += tap * curve4_2;
coords += netFilterWidth;
tap = tex2D(_MainTex, coords);
color += tap * curve4_3;
coords += netFilterWidth;
tap = tex2D(_MainTex, coords);
color += tap * curve4_4;
coords += netFilterWidth;
tap = tex2D(_MainTex, coords);
color += tap * curve4_5;
coords += netFilterWidth;
tap = tex2D(_MainTex, coords);
color += tap * curve4_6;
coords += netFilterWidth;