Individual Learning – Shadertoy

Last week I took a dive into Shadertoy, a website that allows users to write shaders and share them publicly, all within the browser. Many of the effects are truly awe inspiring with incredibly detailed, procedurally generated, 3D scenes ranging from lifelike forests as in the example below by Inigo Quilez (iq), the creator of shadertoy, to abstract and fractal, scenes like the following by Kali.

Rainforest Generators
Rainforest Generators

I created a more simple 2D shader rendering circles by following guides on youtube, mainly this one by iq

From there i started to draw more circles, adding some offsets using sine and cosine functions and i eventually came up with this cool perspective effect which makes a grayscale mask which i then mix between white and the default shader’s colour effect. (Click to see the shader on


I continued to experiment further, using some of the other inputs that shadertoy gives you and also by taking in feedback from the comments (which came in very quickly) to create these next shaders.

Using the Date input and the same circle drawing from the first shader to create a functional clock
Pixelation effect to make make it look like the resolution of the canvas is changing and get a pixel art effect. This shader also includes mouse input to adjust the resolution and the blur on the circle
A smoothstepped Value noise function is used to blend smoothly between two textures. Similar to an effect i have used in unity to blend cameras

Finally I took this one step further and implemented the first effect in a Unity shader so that it can be used as both a material on an object but also as a post process image effect. This wasn’t too difficult, even though Shadertoy uses GLSL and Unity used HLSL, they’re both very similar and most of the code worked fine bar a few vec2s needing to be float2s.

I hope you have enjoyed this week’s post, i certainly had a lot of fun researching the effects and demos that people have created using shadertoy, especially the 3D ones. If you would like to have a go at writing some shadertoy shaders i would recommend looking at iq‘s website here and The Art of Coding on YouTube.

Group Project 3

Last week lots of focus was put into getting an IOS build up and running. It was very time consuming as the Mac not only needed to update but it was running painfully slow, so installing the various tools took a very long time. It didn’t help that i needed ro reinstall Unity a few times as i initially had the wrong version, after that i had to reinstall once again as i could not get the IOS build package to install.

Following the trouble with getting everything installed, i spent the next few hours banging my head against the wall trying to build the XCode project using my free Apple ID. I was following this guide by Unity however the errors and buttons that the guide said should appear were not there for me and upon searching for the errors i was getting, all that i could find was posts made many years ago informing me that i needed to purchase a developer lisence (which the guide said was not needed for a test build).

The trouble i’ve had up until now regarding an IOS release has caused a lot of stress and i am now considering, for the sake of the game, no longer releasing on IOS and bringing forward either the android or PC releases.

I also swapped my Group project work on wednesday with my ILP work from thursday as i had recently been talking about shaders with one of my lecturers and i felt that it would be better for me to work on that while it was fresh on my mind and to finish the sprint the next day.

This week i will not be running a sprint as per my usual week so that i can focus on my written work. I am aware that this is a sizeable chunk of valuable time to be missing from the project, especially as i am now working on the polishing phase but i know from past experience that due to my learning disabilities that i need to allocate more time to written assignments and as the deadline approaches i feel it is more important to get a head start elsewhere so that i do not sacrifice marks on my other modules. I will however be playtesting the latest build at this week’s Ipswich Game Developer Meetup; If you are coming along i would love to get your feedback.

Group Project 2

Development went well this week, I have adjusted my sprint to run from monday to wenesday as I no longer need to work on Visual Scripting on Tuesday.

The UX changes I have made are small however they really make the game look and feel miles better than before and I now have the correct rights to the fonts in the game.

I also wrote a questionnaire for playtesters to give feedback on, I have learned that as i am in a university that questionnaires must be vetted by a Research Ethics board so that is being dealt with today to assure that my form is OK.

Somewhat worryingly I have previously written feedback questionnaires during my BA here and I and my classmates had not been aware of this, i am unsure of whether this is a big problem but i do now know this is the case and how to get it to the board.

Next week I will be adding analytics back in, using Google Firebase. I will also be working on more UX improvements as well as continuing to work on the IOS build.


Individual Learning – Snow Effect

This week I did some more work with vertex displacement and started work on an effect I had wanted to make for a while, even before I started writing shaders: Snow resting on top of an object.

Everything went pretty smoothly, in the vertex function i find the slope angle, if it’s flat enough for snow to be there i set a mask value to white and if not it’s black;  I also displace the vert vertically.

Then in the fragment function I use the mask to lerp between the object’s texture and a snow texture (I left it white as I didn’t have one to hand). The effect is quite appealing though it does stretch the UVs around the displacement and the transition from snow to object can be jagged where there are sharp changes in geometry.

Here’s a video of the shader in action using a rock from the asset store for demonstration.


Once I had finished i decided to look into using tessellation which would give me more vertices to work with and in theory a better result. I found this page on the documentation which demonstrates how to implement tessellation in a surface shader.

I had been writing individual vertex and fragment shaders so I would have to re-write them however it did show me that I could perform vertex functions inside a surface shader using the vertex:vertFunction define in my shader code.

I used the Surface shader examples page on the unity docs to help me with my syntax and quickly got this very similar result the only major differance was that i could now store my mask value as a float in the Input struct and not a float4 in the v2f struct.


I did manage to get Tessellation and Phong Tessellation working without the snow effect but whenever I tried to include my vertex function I would get an error which i assume is caused because unity uses the vertex modifier after tessellation as it would usually be used to perform some sort of height map displacement. The tessellation was surprisingly easy to get up and running though.

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The next step I would like to take is finding a way to use the tessellation with my snow effect to hopefully see an improvement compared to the original shader.

Individual Learning – Vertex Displacement

Last week I wrote a vertex displacement shader that uses a heightmap to displace vertices on a mesh. I managed to get a simple terrain example working very quickly by using an existing heightmap downloaded from google Images.

Here’s what it looks like with a standard plane:


I also created a higher resolution plane in Max to get this more detailed look. It is probably possible to use Tessellation to get the same result at runtime.


Following this i decided to experiment with Unity’s Perlin noise function using what I had learned from creating my own procedurally generated terrain in Monogame. It’s not a very practical approach to terrain generation but it was interesting to experiment with. I also added some colour and a water plane.


I had some trouble with the noise generation as I discovered Unity’s perlin noise function returns the same value at integer values but after i added some values to tweak the scale I was using floats anyway. I also had an issue where the texture didn’t appear to generate as I was getting no displacement or colour on the plane, this however was because I had forgotten to call Texture.Apply() after setting the pixels.

It would be interesting to explore the use of tessellation to skip having to create a pre-subdivided mesh.

Heightmap available here.

Group Project – 1

This week I felt that I had lost direction with the project however after a meeting with my course leader where we discussed the current state of the game and critically analysed the game objectively, through the eyes of a new player, I now have a good idea of the direction I need to move the project in.

The reason for my loss of direction is likely due to the game surpassing my original vision and clouding what really needs to be happening to turn my game, a minimal viable product, into a great game. The discussion has allowed me see what needs to happen now that the polishing phase has begun.

In the next sprint i will begin the polishing phase of the game. My tasks are focussed on streamlining the user experience and removing aspects of the game that are left over from the original game jam submission that are no longer correct.


Visual Scripting – Final Post

Good progress has been made continually throughout the project, I have run into a few problems but I have  prioritised more important features rather than grinding away at the same problem wasting precious time. I am happy that the tool in its current state can produce a natural looking result and shows a lot of potential for further work.

The project is available on my Github here.

To Open the project from Github on your computer you will need the following:

  • Unreal Engine 4, Version 4.18.3
  • Visual Studio 17
    • Windows 10 SDK
    • Windows 8.1 SDK
    • .NET desktop development
    • Desktop development with C++
    • Game Development with C++

I would have liked to have created a Windows build to use as a demo however I got stuck trying to fix a compile error that was not present when using the Compile button in the editor but was present in both Visual Studio and when packaging for windows. In the end I decided that it would be a waste of time spending hours debugging it rather than making sure it’s finished.

Further work

It’s very slow to generate so I would like to optimise everything, specifically getting the mesh data from the terrain and generating the normal.

Currently all of my code is in the Level blueprint so I would like to put it into it’s own blueprint class so that it’s easier to use in multiple levels.

I would like to add support for more biomes with differing settings and even moisture simulation to procedurally determine the location of biomes as per my initial proposal.

I would like to explore the possibility of creating my own heightmaps using Fractal noise, building on what I learned from implementing it in Monogame in my spare time, see Visual Scripting – Spawning Trees.

Finally I would like to use Noise to determine where vegetation should spawn as opposed to the current random number generator; this could possibly allow for me to further speed up the generation time as well as allowing more control to the user for where vegetation should appear.

Asset Ownership

Tree Mesh, Created in 3DS Max

Materials, Created by playing around in the material editor
• Snow Material: Noise node based off world position
• Ground Material: Picks Stone or grass texture dependant on the slope

Sourced Textures, From
• Grass0057_1_S
• TexturesCom_Cliffs0356_1_seamless_S