打开GLES法线贴图着色器照明不正确

Question

我尝试创建一个Open GL ES法线贴图。我使用的网格在Blender中运行良好，但是我的着色器没有。我也尝试在另一个示例程序中使用网格。它似乎只适用于某些面孔。 这是着色器问题还是网格/切线问题？

VP

uniform mat4 worldViewProjMatrix;
uniform mat4 worldViewMatrix;

attribute vec4 vertex;
attribute vec3 normal;
attribute vec3 tangent;
attribute vec3 binormal;
attribute vec4 uv0;

varying vec3 v_Position;
varying vec3 v_Normal;
varying vec3 v_Tangent;
varying vec3 v_Binormal;
varying vec2 v_UV;

void main()
{
    v_Position = (vec4(vertex.xyz, 1.0) * worldViewMatrix).xyz;
    v_Normal = ((worldViewMatrix * vec4(normalize(normal), 0.0)).xyz);
    v_Tangent = ((worldViewMatrix * vec4(normalize(tangent), 0.0)).xyz);
    v_Binormal = ((worldViewMatrix * vec4(normalize(binormal), 0.0)).xyz);//normalize(cross(v_Normal, v_Tangent));
    v_UV = uv0.st;

    gl_Position = worldViewProjMatrix * vec4(vertex.xyz, 1.0);
}

FP

uniform vec4 lightPositionViewSpace;
uniform vec4 surfaceDiffuseColour;
uniform vec4 surfaceAmbientColour;
uniform sampler2D tex0;

varying vec3 v_Position;
varying vec3 v_Normal;
varying vec3 v_Tangent;
varying vec3 v_Binormal;
varying vec2 v_UV;

void main()
{
    mat3 TBN = transpose(mat3(
        v_Tangent,
        v_Binormal,
        v_Normal
    ));

    vec3 lightVector = normalize(lightPositionViewSpace.xyz);//normalize(lightPositionViewSpace.xyz - v_Position);
    lightVector = normalize(lightVector*TBN);

    vec3 normal = normalize(texture2D(tex0, v_UV).rgb*2.0 - 1.0);

    float diffuse = max(dot(normal, lightVector), 0.0);

    gl_FragColor = surfaceDiffuseColour*diffuse+surfaceAmbientColour;
}

Answer 1

我不知道上面的代码有什么问题。 但我写了一个新的，似乎工作。 也许这会帮助那些想要一个简单的Open GLES法线贴图着色器的人：

VP

uniform mat4 worldViewProjMatrix;
uniform vec4 lightDirObjSpace;

attribute vec4 vertex;
attribute vec3 normal;
attribute vec3 tangent;
attribute vec3 binormal;
attribute vec4 uv0;

varying vec2 vTexCoord;
varying vec3 vLightVector;

void main( void )
{
   vTexCoord = uv0.st;

   vLightVector.x = dot( lightDirObjSpace.xyz, tangent );
   vLightVector.y = dot( lightDirObjSpace.xyz, binormal );
   vLightVector.z = dot( lightDirObjSpace.xyz, normal );

   gl_Position = worldViewProjMatrix * vec4(vertex.xyz, 1.0);
}

FP

uniform vec3 surfaceDiffuseColour;
uniform vec3 surfaceAmbientColour;
uniform sampler2D tex0;

varying vec2 vTexCoord;
varying vec3 vLightVector;

void main(void)
{
   vec3 normal = normalize(((texture2D( tex0, vTexCoord ).xyz) * 2.0) - 1.0);

   float diffuse = max(0.0, dot(normalize(normal), normalize(vLightVector)));

   gl_FragColor = vec4(surfaceDiffuseColour * diffuse + surfaceAmbientColour, 1.0);
}