Why shaders control visual rendering in Unity - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to declare a shader property for color.

Unity

Shader "Custom/SimpleColor" {
  Properties {
    _Color ("Color", Color) = [1]
  }
}

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A(1,1,1,1)

Bred

Cfloat4(1,0,0,1)

D"blue"

Attempts:

3 left

💡 Hint

Common Mistakes

Using color names as strings instead of numeric vectors.

Using incorrect syntax like float4 without proper context.

Shader color properties use a vector with four float values representing RGBA, like (1,1,1,1) for white.

2fill in blank

medium

Complete the code to sample the main texture in the fragment shader.

Unity

fixed4 frag(v2f i) : SV_Target {
  fixed4 col = tex2D([1], i.uv);
  return col;
}

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Auv

Bsampler2D

Cfloat4

D_MainTex

Attempts:

3 left

💡 Hint

Common Mistakes

Using the type name instead of the sampler variable.

Passing UV coordinates incorrectly.

The tex2D function samples a texture using its sampler variable, usually named _MainTex.

3fill in blank

hard

Fix the error in the shader code to correctly multiply color by light intensity.

Unity

fixed4 frag(v2f i) : SV_Target {
  fixed4 col = tex2D(_MainTex, i.uv);
  fixed light = [1].r;
  return col * light;
}

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AlightIntensity

BlightDir

ClightColor

DlightPos

Attempts:

3 left

💡 Hint

Common Mistakes

Using variable names that don't exist or hold different data.

Multiplying by a vector instead of a scalar.

The light color variable holds intensity information; multiplying color by lightColor.r applies lighting.

4fill in blank

hard

Fill both blanks to declare and use a float property controlling brightness.

Unity

Properties {
  _Brightness ("Brightness", Float) = [1]
}

fixed4 frag(v2f i) : SV_Target {
  fixed4 col = tex2D(_MainTex, i.uv);
  col.rgb *= [2];
  return col;
}

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A1.0

B0.5

C_Brightness

D_Color

Attempts:

3 left

💡 Hint

Common Mistakes

Using the wrong property name in the shader code.

Setting default value as a string instead of a number.

The brightness property is declared with a default value 1.0 and used in the shader as _Brightness to scale color.

5fill in blank

hard

Fill all three blanks to create a simple vertex shader that moves vertices up by a float amount.

Unity

Shader "Custom/MoveUp" {
  Properties {
    _MoveAmount ("Move Amount", Float) = [1]
  }
  SubShader {
    Pass {
      CGPROGRAM
      #pragma vertex vert
      #pragma fragment frag

      float [2];

      struct appdata {
        float4 vertex : POSITION;
      };

      struct v2f {
        float4 pos : SV_POSITION;
      };

      v2f vert(appdata v) {
        v2f o;
        o.pos = UnityObjectToClipPos(v.vertex);
        o.pos.y += [3];
        return o;
      }

      fixed4 frag(v2f i) : SV_Target {
        return fixed4(1,1,1,1);
      }
      ENDCG
    }
  }
}

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A0.5

B_MoveAmount

Cv.vertex.y

DmoveAmount

Attempts:

3 left

💡 Hint

Common Mistakes

Using a different variable name than the property name.

Trying to add vertex.y directly instead of the property.

The float property _MoveAmount is declared with default 0.5, then used as variable _MoveAmount to add to vertex y position.