Black Thorn Prod Challenge 2

Last weekend I participated in my second Black Thorn Prod challenge. If you are not familiar with Black Thorn Prod, it’s a Youtuber that makes game dev challenge videos. Mostly about having many developers work without communicating.

Here is the first one I participated in:

Reading through the comments, it seems people liked my random dancing penguin 😄🐧💃.

This time though, I decided to keep things under control. I focused mainly of improving the existing features. This is the video I sent to BlackThornProd:

Code

The code is pretty simple. But I thought I would note somethings.

Since I’m using a render texture, I want to reset the texture each time a new drawing is spawned. I reset it using the GL (Graphcis Library) API.

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public void ClearOutRenderTexture(RenderTexture renderTexture)
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{
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  RenderTexture rt = RenderTexture.active;
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  RenderTexture.active = renderTexture;
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  GL.Clear(true, true, Color.clear);
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  RenderTexture.active = rt;
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}

Something else to note is how to change the properties of a particle system in code. I always forget that I have to change the “main” property. Since it’s a struct we can’t just change the values, so you have to put the value in a variable, make the changes and assign it back.

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public override void ApplyStrokeVariables(Pencil pencil, int strokeCount)
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{
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    var main = m_ParticleSystem.main;
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    //Apply Stroke variables
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    if (pencil.IsUsingGradient)
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    {
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        Gradient newGradient = new Gradient();
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        newGradient.SetKeys(
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            new GradientColorKey[] { new GradientColorKey(pencil.PrimaryColor, 0.0f), new GradientColorKey(pencil.SecondaryColor, 1.0f) },
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            new GradientAlphaKey[] { new GradientAlphaKey(pencil.Opacity, 0.0f), new GradientAlphaKey(pencil.Opacity, 1.0f) });
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        var startColor = main.startColor;
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        startColor.mode = ParticleSystemGradientMode.Gradient;
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        startColor.gradient = newGradient;
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        main.startColor = startColor;
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    }
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    else
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    {
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        var startColor = main.startColor;
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        startColor.mode = ParticleSystemGradientMode.Color;
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        var color = pencil.PrimaryColor;
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        startColor.color = new Color(color.r, color.b, color.b, pencil.Opacity);
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        main.startColor = startColor;
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    }
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    var startSize = main.startSize;
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    startSize.constant = pencil.StrokeWidth;
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    main.startSize = startSize;
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    //keep the sortOrder such that each stroke is on top of previous ones.
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    m_ParticleSystem.GetComponent<Renderer>().sortingOrder = strokeCount;
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}

Outro

I enjoyed working on this one, I had a clear idea of the result I wanted and how to achieve it. In the end I probably spent around 3-4hours to implement all those change and around 1-2hours for making the video.

All in all a good interesting weekend project.