OMG Software

Other Developer Communities 2019

Previously I shared details of the communities/user groups that are hosted by Microsoft South Africa at their community nights, but those are not the only groups you can join in Johannesburg, South Africa.

In no particular order:

Google Developer Group Johannesburg – For developers who are interested in Google’s developer technology.
Artificial Intelligence ZA – Helping the technical and business community learn more about AI.
Jozi-JUG – Discusses Java Virtual Machine languages and related technologies.
Gauteng Python User Group – Discussing anything Python related.

I’ve dated this list 2019 in case things change in the years to come.

Microsoft Community Nights 2019

Software doesn’t flourish in isolation and neither does a creative mind.

Participating in the larger community of software engineers around you provides multiple benefits such as: learning, friendship, job opportunities and skills development by sharing your own projects and experiences.

Microsoft South Africa hosts a free community night every 2nd Tuesday of the month in Johannesburg, South Africa and below are the user groups with links to more information that are hosted (I’ve dated this article 2019 in case the groups change in the coming years).

In no particular order:

Johannesburg Azure User Group – Discussing technical or business topics related to Microsoft Azure
Developer User Group @DeveloperUG – Who love all things developer.
Johannesburg Office 365 User Group – Learning & sharing their experiences with Office 365 and supporting technologies
Johannesburg School of AI – Offering world-class AI education to anyone on Earth
Johannesburg SQL User Group – Created to give the MS SQL server community an opportunity to get together
Johannesburg PowerApps & Flow User Group – Sharing & building experience on these highly exciting platforms
Johannesburg MS Developer User Group @jhbmsdug – Your local developer community for Microsoft technologies & member of the .NET Foundation
Make Games South Africa @MakeGamesSA – Sharing experience creating games, art & sound design

If you’re not in Johannesburg I still highly encourage you to seek out your local communities and at least sit in the back and listen-in to the proceedings.

Integrating DiffMerge with Git Bash

Here’s the configuration I use to get DiffMerge working with Git Bash.

DiffMerge should already be installed into its default directory (otherwise you will have to edit the shell files available below).

If it doesn’t already exist, create the file .gitconfig in C:/Users/<your username>/ and copy the following content:

[merge]
    tool = diffmerge
[diff]
    tool = diffmerge
[mergetool]
    keepBackup = false
[mergetool "diffmerge"]
    cmd = git-mergetool-diffmerge-wrapper.sh "$LOCAL" "$BASE" "$REMOTE" "$MERGED"
[difftool "diffmerge"]
    cmd = git-difftool-diffmerge-wrapper.sh "$LOCAL" "$REMOTE"
[user]
	name = Andre Odendaal
	email = aodendaal@gmail.com
[difftool]
	prompt = false

[merge]

tool = diffmerge

[diff]

tool = diffmerge

[mergetool]

keepBackup = false

[mergetool "diffmerge"]

cmd = git-mergetool-diffmerge-wrapper.sh "$LOCAL" "$BASE" "$REMOTE" "$MERGED"

[difftool "diffmerge"]

cmd = git-difftool-diffmerge-wrapper.sh "$LOCAL" "$REMOTE"

[user]

name = Andre Odendaal

email = aodendaal@gmail.com

[difftool]

prompt = false

Change the name to your name and the email to the email you use for your repository.

Next download and unzip these wrapper files into C:/Program Files/git/cmd/

And you should be good to go!

Machine Learning’s “Hello, World!”

My implementation of Machine Learning’s “Hello, World!” program, training a neural network to recognize hand-written digits from the MNIST (Modified National Institute of Standards and Technology) database. Built in Python using Tensorflow.

I followed the MNIST For ML Beginners tutorial.

In case you’re wondering, the script above is a Jupyter Notebook, hosted on GitHubGist

If you’re interested in Machine Learning, before you do anything else, I highly recommend watching these two videos from 3Blue1Brown.

I’m also keeping all my notes on Machine Learning in a shared Google doc, Implement Machine Learning.

Volumetric Sphere Shader

This is my implementation of Alan Zucconi’s tutorial on Volumetric Rendering.

This is a vertex and fragment shader.

An important observation I made is the order of declaring functions is important. A function must be declared before it can be called by another function.

I expanded on the tutorial by declaring Properties, making the center of the sphere and its size available from Unity’s inspector. This way I could play with values without updating the shader each time.

Properties
{
	_Center ("Center", Vector) = (0, 0, 0, 0)
	_Radius ("Radius", Float) = 0.5
}

Properties

{

_Center ("Center", Vector) = (0, 0, 0, 0)

_Radius ("Radius", Float) = 0.5

}

In the vertex function I get the world position of the vertex for use in the fragment function.

v2f vert (appdata_base input)
{
	v2f output;
	output.vertex = UnityObjectToClipPos(input.vertex);
	output.wPos = mul(unity_ObjectToWorld, input.vertex).xyz; 

	return output;
}

v2f vert (appdata_base input)

{

v2f output;

output.vertex = UnityObjectToClipPos(input.vertex);

output.wPos = mul(unity_ObjectToWorld, input.vertex).xyz;

return output;

}

The fragment function is where most of the work in this shader happens.

fixed4 frag (v2f input) : SV_Target
{
	float3 worldPos = input.wPos;
	float3 viewDir = normalize(input.wPos - _WorldSpaceCameraPos);

	fixed4 color;

	if (raymarchHit(worldPos, viewDir))
	{
		color = fixed4(1,0,0,1);
	}
	else
	{
		color = fixed4(1,1,1,1);
	}

	return color;
}

fixed4 frag (v2f input) : SV_Target

{

float3 worldPos = input.wPos;

float3 viewDir = normalize(input.wPos - _WorldSpaceCameraPos);

fixed4 color;

if (raymarchHit(worldPos, viewDir))

{

color = fixed4(1,0,0,1);

}

else

{

color = fixed4(1,1,1,1);

}

return color;

}

Full listing:

Shader "Custom/VolumetricSphere"
{
	Properties
	{
		_Center ("Center", Vector) = (0, 0, 0, 0)
		_Radius ("Radius", Float) = 0.5
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }

		Pass
		{
			CGPROGRAM
			#pragma vertex vert
			#pragma fragment frag
			
			#include "UnityCG.cginc"
			
			float3 _Center;
			float _Radius;
		
			#define STEPS 64
			#define STEP_SIZE 0.01

			struct v2f
			{
				float4 vertex : SV_POSITION;
				float3 wPos : TEXCOORD1;
			};

			bool sphereHit(float3 pos)
			{
				return distance(pos, _Center) < _Radius;
			}

			bool raymarchHit(float3 worldPos, float3 viewDir)
			{
				for (int i = 0; i < STEPS; i++)
				{
					if (sphereHit(worldPos))
					{
						return true;
					}

					worldPos += viewDir * STEP_SIZE;
				}

				return false;
			}

			v2f vert (appdata_base input)
			{
				v2f output;
				output.vertex = UnityObjectToClipPos(input.vertex);
				output.wPos = mul(unity_ObjectToWorld, input.vertex).xyz; 

				return output;
			}

			fixed4 frag (v2f input) : SV_Target
			{
				float3 worldPos = input.wPos;
				float3 viewDir = normalize(input.wPos - _WorldSpaceCameraPos);

				fixed4 color;

				if (raymarchHit(worldPos, viewDir))
				{
					color = fixed4(1,0,0,1);
				}
				else
				{
					color = fixed4(1,1,1,1);
				}

				return color;
			}

			ENDCG
		}
	}
}

Shader "Custom/VolumetricSphere"

{

Properties

{

_Center ("Center", Vector) = (0, 0, 0, 0)

_Radius ("Radius", Float) = 0.5

}

SubShader

{

Tags { "RenderType"="Opaque" }

Pass

{

CGPROGRAM

#pragma vertex vert

#pragma fragment frag

#include "UnityCG.cginc"

float3 _Center;

float _Radius;

#define STEPS 64

#define STEP_SIZE 0.01

struct v2f

{

float4 vertex : SV_POSITION;

float3 wPos : TEXCOORD1;

};

bool sphereHit(float3 pos)

{

return distance(pos, _Center) < _Radius;

}

bool raymarchHit(float3 worldPos, float3 viewDir)

{

for (int i = 0; i < STEPS; i++)

{

if (sphereHit(worldPos))

{

return true;

}

worldPos += viewDir * STEP_SIZE;

}

return false;

}

v2f vert (appdata_base input)

{

v2f output;

output.vertex = UnityObjectToClipPos(input.vertex);

output.wPos = mul(unity_ObjectToWorld, input.vertex).xyz;

return output;

}

fixed4 frag (v2f input) : SV_Target

{

float3 worldPos = input.wPos;

float3 viewDir = normalize(input.wPos - _WorldSpaceCameraPos);

fixed4 color;

if (raymarchHit(worldPos, viewDir))

{

color = fixed4(1,0,0,1);

}

else

{

color = fixed4(1,1,1,1);

}

return color;

}

ENDCG

}

Wavy Ocean Shader

Let me explain my Wavy Ocean Shader available from my Shader Gallery on GitHub.

This is a vertex and fragment shader.

The vertex function shifts the UV map along the x-axis in proportion to the sine of the y-axis plus time.

vertOutput vert (appdata_base input)
{
  vertOutput output;

  output.vertex = UnityObjectToClipPos(input.vertex);

  float2 dtexcoord = input.texcoord;
  dtexcoord.x = dtexcoord.x + sin(dtexcoord.y * 2 * mpi + _Time[0] * 2) * 0.1;

  output.uv = TRANSFORM_TEX(dtexcoord, _MainTex);

  return output;
}

vertOutput vert (appdata_base input)

{

vertOutput output;

output.vertex = UnityObjectToClipPos(input.vertex);

float2 dtexcoord = input.texcoord;

dtexcoord.x = dtexcoord.x + sin(dtexcoord.y * 2 * mpi + _Time[0] * 2) * 0.1;

output.uv = TRANSFORM_TEX(dtexcoord, _MainTex);

return output;

}

The fragment function just gets the color from the texture based on the new UV map coordinate.

fixed4 frag (vertOutput input) : SV_Target
{
  fixed4 col = tex2D(_MainTex, input.uv);
  return col;
}

fixed4 frag (vertOutput input) : SV_Target

{

fixed4 col = tex2D(_MainTex, input.uv);

return col;

}

Full listing:

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/WavyOcean"
{
  Properties
  {
    _MainTex ("Texture", 2D) = "white" {}
  }
  SubShader
  {
    Tags { "RenderType" = "Opaque" }
    LOD 100

    Pass
    {
      CGPROGRAM
      #pragma vertex vert
      #pragma fragment frag

      #include "UnityCG.cginc"

      static const float mpi = 3.141592654;

      sampler2D _MainTex;
      float4 _MainTex_ST;

      struct vertOutput
      {
        float2 uv : TEXCOORD0;
        float4 vertex : SV_POSITION;
      };

      vertOutput vert (appdata_base input)
      {
        vertOutput output;

        output.vertex = UnityObjectToClipPos(input.vertex);

        float2 dtexcoord = input.texcoord;
        dtexcoord.x = dtexcoord.x + sin(dtexcoord.y * 2 * mpi + _Time[0] * 2) * 0.1;

        output.uv = TRANSFORM_TEX(dtexcoord, _MainTex);

        return output;
      }

      fixed4 frag (vertOutput input) : SV_Target
      {
        fixed4 col = tex2D(_MainTex, input.uv);
        return col;
      }
      ENDCG
    }
  }
}

// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)'

Shader "Custom/WavyOcean"

{

Properties

{

_MainTex ("Texture", 2D) = "white" {}

}

SubShader

{

Tags { "RenderType" = "Opaque" }

LOD 100

Pass

{

CGPROGRAM

#pragma vertex vert

#pragma fragment frag

#include "UnityCG.cginc"

static const float mpi = 3.141592654;

sampler2D _MainTex;

float4 _MainTex_ST;

struct vertOutput

{

float2 uv : TEXCOORD0;

float4 vertex : SV_POSITION;

};

vertOutput vert (appdata_base input)

{

vertOutput output;

output.vertex = UnityObjectToClipPos(input.vertex);

float2 dtexcoord = input.texcoord;

dtexcoord.x = dtexcoord.x + sin(dtexcoord.y * 2 * mpi + _Time[0] * 2) * 0.1;

output.uv = TRANSFORM_TEX(dtexcoord, _MainTex);

return output;

}

fixed4 frag (vertOutput input) : SV_Target

{

fixed4 col = tex2D(_MainTex, input.uv);

return col;

}

ENDCG

}