Skip to main content

Normal Based Texture Shader For Unity

Normal Based Texturing

This shader uses the normals of the mesh to determine what texture is to be applied.
We will get to know how to access normal data in the shader as well as how to apply a texture based on it.
This is what we will end up with after getting normal data :
Image Shows Normals Of Objects
Now let's look the structs needed :
struct appdata
 float4 vertex : POSITION;
 float2 uv : TEXCOORD0;
 float3 normal : NORMAL;
struct v2f
 float2 uv : TEXCOORD0;
 fixed4 norm : COLOR;
 float4 vertex : SV_POSITION;
As you can see I added an appdata member called float3 normal of type 'NORMAL', this will be used in the vertex shader to then later on pass to the fragment shader.
In the v2f struct I added a member called fixed4 norm of type COLOR, this will be used in fragment shader to do the actual work.
Let's see what the vertex shader is doing now:
v2f vert (appdata v)
 v2f o;
 o.vertex = UnityObjectToClipPos(v.vertex); = v.normal;
 o.norm.w = 1.0;
 o.uv = TRANSFORM_TEX(v.uv, _Tex1);
 return o;
It's taking in an appdata struct and outputting a v2f struct - which will be used in fragment shader.
We are assigning the norm value with the actual normal data from the mesh.
As norm is actually a colour RGB is XYZ, so o.norm = v.normal will assign the RGB values directly and o.norm.w = 1.0 makes sure alpha is at 100%.
So if you want the output from the image you saw before you make the fragment shader output the 'norm' value :
fixed4 frag (v2f i) : SV_Target
 return abs(i.norm);
We are using abs(i.norm) because we don't want dark or black parts to show up on the object.
Now we will see how to add textures based on the normal in the fragment shader.
We will end up with something that looks like this:
3 textures based on x , y and z axis
We need to add three texture properties:
 _Tex1 ("Texture 1", 2D) = "white" {}
 _Tex2("Texture 2", 2D) = "white"{}
 _Tex3("Texture 3", 2D) = "white"{}
What are they:
sampler2D _Tex1;
sampler2D _Tex2;
sampler2D _Tex3;
float4 _Tex1_ST;
Now finally... the fragment shader:
fixed4 frag (v2f i) : SV_Target
 fixed4 col1 = tex2D(_Tex1, i.uv);
 fixed4 col2 = tex2D(_Tex2, i.uv);
 fixed4 col3 = tex2D(_Tex3, i.uv);
 col1 *= abs(dot(, float3(0, 0, 1)));
 col2 *= abs(dot(, float3(0, 1, 0)));
 col3 *= abs(dot(, float3(1, 0, 0)));
 return ((col1 +col2 + col3)/3) * 1.2;
After we take the three colours from the UV map we then multiply each of those with a value that shows how close the normal is to the X, Y & Z axis.
col1 *= abs(dot(, float3(0, 0, 1)));
The dot function between the normal and an axis will return a value between -1.0 and +1.0 then we use the abs ( absolute ) function which gives only the magnitude without the sign.
We then use that value and multiply with the colour.
return ((col1 +col2 + col3)/3) * 1.2;
We return a colour which is the average of all those colours and we multiply by a value because the image is a bit dark.
You can get source code HERE.
If you like programming shaders make sure you check these out : Shader Tutorials
Support Bitshift Programmer by leaving a like on Bitshift Programmer Facebook Page and be updated as soon as there is a new blog post.
If you have any questions that you might have about shaders or unity development in general don't be shy and leave a message on my facebook page or down in the comments.


Assets Worth Checking Out


Curved Surface Shader [ Unity Implementation ]

Curved Surface Shader This is the shader that we will be having at the end of this tutorial.
 The curved surface shader is capable of achieving really varied visual effects from showing space-time curve due to gravity to a generic curved world shader that is seen in endless runners like Subway Surfers.
The concepts that you learn here can open you up to a new way of looking at shaders and if you didn't think they were the coolest thing ever already, hopefully let this be the turning point.😝.

Both the examples show above use the same exact material is just that different values have been passed to the shader.
Start by creating a new unlit shader in Unity and we will work our way from there.
First we define what the properties are:
_MainTex("Texture", 2D) = "white" {} _BendAmount("Bend Amount", Vector) = (1,1,1,1) _BendOrigin("Bend Origin", Vector) = (0,0,0,0) _BendFallOff("Bend Falloff", float) = 1.0 _BendFallOffStr("Falloff s…

Pixelation Shader - Unity Shader

Pixelation Shader This is the correct way (one of many) of showing pixelation as a post-processing effect. This effect will work in any aspect ratio without any pixel size scaling issues as well as it is very minimal in terms of coding it up.

In order to get this to work 2 components have to be set up:
1) The pixelation image effect
2) The script - which will be attached to the camera

So let's get started by creating a new image effect shader.
We will take a look at our Shaderlab properties :
_MainTex("Texture", 2D) = "white" {} That's it, Everything else will be private and not shown in the editor.
Now we will see what are defined along with the _MainTex but are private.
sampler2D _MainTex; int _PixelDensity; float2 _AspectRatioMultiplier; We will pass _PixelDensity & _AspectRatioMultiplier values from the script.
As this is an image effect there is no need to play around with the vertex shader.
Let's take a look at our fragment shader:
fixed4 frag (…

Toon Liquid Shader - Unity Shader

Toon Liquid Shader This is how the shader will end up looking :
This shader is pretty neat and somewhat easy to implement as well as to understand. Since we will be adding some basic physics to the toon water as it is moved about we will have to support that in the vertex shader as well.
So let's start by looking at the properties :
Properties { _Colour ("Colour", Color) = (1,1,1,1) _FillAmount ("Fill Amount", Range(-10,10)) = 0.0 [HideInInspector] _WobbleX ("WobbleX", Range(-1,1)) = 0.0 [HideInInspector] _WobbleZ ("WobbleZ", Range(-1,1)) = 0.0 _TopColor ("Top Color", Color) = (1,1,1,1) _FoamColor ("Foam Line Color", Color) = (1,1,1,1) _Rim ("Foam Line Width", Range(0,0.1)) = 0.0 _RimColor ("Rim Color", Color) = (1,1,1,1) _RimPower ("Rim Power", Range(0,10)) = 0.0 } Just the usual stuff that we are used to. The only thing that may stand out is the [HideInInspector] tag, This works j…

Alto's Adventure Style Procedural Surface Generation Part 1

Alto's Adventure Style - Procedural Surface Generation This game appears to be a strictly 2D game but if you have played it enough you will notice that some of the art assets used look like it's 3D ( I don't know if they are tho ). If you haven't played the game you are missing out on one the most visually pleasing and calming games out there ( There is literally a mode called Zen mode in the game ).
Anyway, I am going to show you how to make a procedural 2D world ( without the trees, buildings and background ) like in Alto's Adventure.
But you may notice I have a plane which is in in the Z-axis giving a depth to the surface which is not there in Alto's Adventure but if you want to know how to do it then that will be in part 2.
To achieve the same effect of Alto's Adventure ( I'm leaving that up to you ) only minimal changes are needed to the code that I am going to explain.
We are going to be using the plane mesh in unity for creating the 2D surface as th…

Gift Wrapping Convex Hull Algorithm With Unity Implementation

Convex Hull Algorithm Convex Hull algorithms are one of those algorithms that keep popping up from time to time in seemingly unrelated fields from big data to image processing to collision detection in physics engines, It seems to be all over the place. Why should you care? Cus you can do magic with it and it seems so simple to implement when you first hear about it, but when you start thinking about it, you will realize why it's not such a straightforward thing to do.
Now that I got you interested (hopefully) and now we will see just what a convex hull is.
As you may have noticed a perimeter was made with the same points that was given and these perimeter points enclose the entire set of points.
Now we have to clear up the term 'Convex'.
Convex means no part of the object is caved inwards or that none of the internal angles made by the points exceed 180 degrees.
In this example of a concave shape internal angles go beyond 180 degrees.
What are those red lines for? Well...…