#Custom Node

1 messages · Page 1 of 1 (latest)

restive lotus
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Threading

bright olive
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Well, in your custom node hlsl you'll need to make a loop 🙂

restive lotus
# 

    void CalculatingColHeight(float UVx, out float UVy )
    {
        for (int i = 0; i < positionArrays.Length; i++)
        {
            if(UVx < positionArrays[i].x)
            {
                UVy = positionArrays[i].y;
                return;
            }
        }
    }```
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Something like this I guess ?

bright olive
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Note that you could achieve the same result without custom nodes and loops if you simply decide to use a texture instead of the vector2 array

restive lotus
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I'm considering it to be honest but I am currently exploring my options ^^

bright olive
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Oh wait, I've maybe mis-interpretted your example : are the "columns" always evenly spaced like in your example, or can they vary in width ?

restive lotus
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Also I don't know how generating a 1600pixel texture everyframe will impact performance (I don't knox anything about that though)

restive lotus
bright olive
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And evenly distributed ?

restive lotus
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Yep

bright olive
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In that case, the texture method would probably be better

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And you don't need to generate the texture every frame, you generate it once, and only update when needed.

restive lotus
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So I create the texture with my y value (using alpha or red values), I pass it with the increment to my shader and I make the shader read the this value to converting back to a float ? (if I understand correctly)

bright olive
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Let me build an example very quickly

restive lotus
bright olive
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A simple scrolling isn't enough ?

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Or maybe it is some simulation ? 🙂

restive lotus
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The idea is to create a body of water where I can control waves patterns while retaining a pixel art look 🙂 I have tried different options in the past but always encountered problems.

bright olive
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Example if the values are in a texture :

image.png
restive lotus
bright olive
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Now, indeed if you want to change a single pixel of the texture, it all needs to be uploaded to the GPU with "Apply()".

So depend how many values in the vector array you are changing per frame.
If it's only a single one, vector arrays might be more performant.
If it's the whole array, I think it would have comparable perfs as the texture.

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You can achieve a similar effect with the custom HLSL in a simple way :

float2 array[];
void WaveMask_float( float2 uv, out float )
{
  int index = floor( uv.x * arraySize );
  return step( uv.y, array[index] );
}
restive lotus
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Well technically as you said the distribution will be uniform depending on the spacing parameter so I only need a float array. But every float would change per frame yeah

bright olive
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Well, so a texture is easier to handle I guess (and can more easilly be resized) 🙂

restive lotus
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So let's imagine I have my code. On FUpdate I do the calculations to determine the position of each pixel. Once the calculations are over I create a new texture depending on the array (with red values for exemple). I just need to get this texture to the shader or do I need something else ? (Sorry I'm a bit novicde in computer graphics ^^")

bright olive
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In Start, you create the texture with the required size, and assign it to the material.

On Update, you :

  • calculate your pixels positions in a c# color array (yep, no choice, it needs to be of the Color type)
  • set the value in the R field for each of them
  • Once all the values are calculated (after the for loop
  • call texture.SetPixels( ... ) with the color array
  • call texture.Apply() to send the data to the GPU.

No need to create a texture every frame, and no need to re-apply it to the material.

restive lotus
# bright olive In Start, you create the texture with the required size, and assign it to the ma... 
{
    int size;
    Texture2D texture;
    float[] pixelPos;
    Color[] colorsAray;

    SpriteRenderer spriteRenderer;
    // Start is called before the first frame update
    void Start()
    {
        size = (int)transform.localScale.x * 16;
        colorsAray = new Color[size];
        pixelPos = new float[size];
        texture = new Texture2D(size, 1, TextureFormat.ARGB32, false);
        //set up Material Property Blmock and assign texture to material
    }

    void FixedUpdate()
    {
        //Do some shit to calculate pixels positions in pixelPos

        for (int i = 0; i < size; i++)
        {
            colorsAray[i] = new Color(pixelPos[i],0,0);
        }

        texture.SetPixels(colorsAray);
        texture.Apply();
    }
}```

Something like this ?
bright olive
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Something like this. Could be a bit better optimisation wise, but should work

restive lotus
bright olive
restive lotus
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I see ! The pixelPos array will also be used to trigger particles and displacement during collisions so this is fine 🙂

restive lotus
restive lotus