使用自定义的材质后，图片不展示了

Creator 3.x
#1

cocos creator 3.8.1使用自定义的材质后，图片不展示了，着色器代码如下：
// Effect Syntax Guide: https://docs.cocos.com/creator/manual/zh/shader/index.html

CCEffect %{
techniques:

  • name: shadow
    passes:
    • vert: shadow-vs:vert
      frag: shadow-fs:frag
      blendState:
      target:
      • blend: true
        resterizerState:
        cullMode: node
        properties: &props
        mainTexture: { value: white }
        alphaThreshold: { value: 0.5}
        wide: { value: 0.5}
        radius: { value: 1.}
        light: { value: 1.}
        }%

CCProgram shadow-vs %{
precision highp float;
#include <builtin/uniforms/cc-global>
#if USER_LOCAL
#include <builtin/uniforms/cc-local>
#endif

in vec3 a_position;
in vec4 a_color;
out vec4 v_color;

#if USE_TEXTURE
in vec2 a_uv0;
out vec2 v_uv0;
#endif

vec4 vert () {
vec4 pos = vec4(a_position, 1);

#if CC_USE_MODEL
  pos = cc_matViewProj * cc_matWorld * pos;
#else
  pos = cc_matViewProj * pos;
#endif

#if USE_TEXTURE
  v_uv0 = a_uv0;
#endif

v_color = a_color;

return pos;

}
}%

CCProgram shadow-fs %{
precision highp float;

#include <builtin/internal/alpha-test>

in vec4 v_color;

#if USE_TEXTURE
in vec2 v_uv0;
uniform sampler2D mainTexture;
#endif

uniform Constant {
float wide;
float radius;
float light;
};

vec4 frag () {
vec4 o = vec4(0, 0.45, 0.4, 1);
o.a *= light;
vec2 uv = v_uv0 - 0.5;
o.a -= 1.0 - smoothstep(1. - wide, 1., length(uv) * 1./radius);
o *= v_color;
ALPHA_TEST(o);
return o;
}
}%