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Today we learn mathematics Shader achieve a Cartesian coordinate system through the Unity Shader, so that we become more familiar with the mathematical methods used in Unity Shader. XY axis by a mathematical coordinate system, XY-axis direction and the unit cells constituting the arrow. The final results as shown
The first step we use basic mathematical method to draw squares. Create a new Unlit Shader in Unity. Delete _MainTexture property and related variables required to define the grid shader property. Attribute is defined as follows
The Properties
{
// background color
_BgColor ( " BgColor " , Color) = ( . 1 , . 1 , . 1 , . 1 )
// out of line color
_LinesColor ( " LinesColor " , Color) = ( 0.7 , 0.7 , 0.7 , 1.0 )
// times level line color
_SubLinesColor ( " SubLinesColor " , color) = ( 0.95 , 0.95 , 0.95 , 1.0 )
// scale
_Scale("Scale",range(1,100)) = 10
_Subdiv("Subdiv",range(1,10)) = 10
}
Here are the properties of the background color, line color is the color of the secondary line segments scaling value and a minimum scale value.
Enter the following code in the Fragment Shader
vec2 pos = i.uv;
Pos define a variable, and scale it.
pos * = _Scale;
By taking the remainder operation, duplicate values obtained, was added _Scale = 10, will be repeated 10 times between 0-1
POS = FRAC (POS);
vec4 fragColor = _BgColor;
By step, the return value of the lower left corner, where the method step, determining if equivalent,
| step(a, x) | Returns (x >= a) ? 1 : 0 |
BL = vec2 STEP ( 0.01 , POS); // bottom left
vec2 TR = STEP ( 0.01 , 1.0 -POS); // upper right
The result of the above two operations of multiplication, will get all> 0, the position of
a float Alpha = bl.x tr.x * * * bl.y tr.y;
The method then mix by mixing basic color and line color.
Mix = fragColor (fragColor, _LinesColor, . 1 -alpha);
the pos Subdiv times enlarged, the above operation is repeated, to give decile scale squares
vec2 BL2 = STEP ( 0.01 , FRAC (pos * _Subdiv)); // bottom left
vec2 tr2 = STEP ( 0.01 , 1.0 - FRAC (POS _Subdiv *)); // the upper right
a float alpha2 = bl2.x tr2.x * * * bl2.y tr2.y;
fragColor = Mix (fragColor, _SubLinesColor, . 1 -alpha2);
returns the final color.
return fragColor;
After completion of the above effects obtained finally, to obtain the final results are as follows: the FIG _Scale = 2, _Subdive = 5
The complete code is as follows:
Shader " Unlit / StepGrid "
{
the Properties
{
// background color
_BgColor ( " BgColor " , Color) = ( . 1 , . 1 , . 1 , . 1 )
// out of line color
_LinesColor ( " LinesColor " , Color) = ( 0.7 , 0.7 , 0.7 , 1.0 )
// secondary line color
_SubLinesColor ( " SubLinesColor " , color) = ( 0.95 , 0.95 , 0.95,1.0)
//缩放
_Scale("Scale",range(1,100)) = 10
_Subdiv("Subdiv",range(1,10)) = 10
}
SubShader
{
Tags { "RenderType"="Opaque" }
LOD 100
Pass
{
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#define vec2 half2
#define vec3 half3
#define vec4 half4
#define mix lerp
#include "UnityCG.cginc"
struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
};
struct v2f
{
float2 uv : TEXCOORD0;
float4 vertex : SV_POSITION;
};
float _Scale;
float _Subdiv;
fixed4 _BgColor;
fixed4 _LinesColor;
fixed4 _SubLinesColor;
v2f vert (appdata v)
{
v2f o;
o.vertex = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
return o;
}
fixed4 frag (v2f i) : SV_Target
{
vec2 pos = i.uv;
pos *= _Scale;
pos=frac(pos);
vec4 fragColor = _BgColor;
vec2 bl = step(0.01,pos); // 左下
vec2 tr = step(0.01,1.0-pos); // 右上
float alpha =bl.x * bl.y * tr.x * tr.y;
fragColor = mix(fragColor, _LinesColor, 1-alpha);
vec2 bl2 = step(0.01,frac(pos*_Subdiv)); // 左下
vec2 tr2 = step(0.01,1.0-frac(pos*_Subdiv)); // upper right
a float alpha2 = bl2.x tr2.x * * * bl2.y tr2.y;
fragColor = Mix (fragColor, _SubLinesColor, . 1 -alpha2);
return fragColor;
}
ENDCG
}
}
}
simple Shader above to achieve Shader with a very basic scale of the grid. The next section we will continue to optimize.
