Change pixels on a QUAD texture

Unity Engine
1

Hi,
I’m trying to do a simple thing: take an original texture put on a Quad and then draw new pixels at certain positions.

The problem is that when I do this the texture becomes all grey and the pixels drawn seem to have a strange blurring effect.

The code is the following:

MeshRenderer meshRenderer = quad.GetComponent<MeshRenderer>();
texture = new Texture2D(meshRenderer.material.mainTexture.width, meshRenderer.material.mainTexture.height);
meshRenderer.material.mainTexture = texture;

texture.SetPixel(0, 0, Color.red);
texture.SetPixel(1, 0, Color.red);
texture.SetPixel(2, 0, Color.red);

texture.Apply();

Look at images:

Original 800x600

7574215--938185--Unity_JwNeOZI4OM.png
7574215--938185--Unity_JwNeOZI4OM.png878×715 79.8 KB

After set pixels:

7574215--938188--Unity_Qg5OoD7FJ5.png
7574215--938188--Unity_Qg5OoD7FJ5.png606×623 4.1 KB

I don’t understand the problem! Please help.
Thanks.

2

you need to change the settings on the texture, set it to filtermode point, no compression ettc

3

Yes, this is the problem but I also missed getting the original pixels… :sweat_smile:

Below the code:

 MeshRenderer meshRenderer = quad.GetComponent<MeshRenderer>();

        texture = new Texture2D(meshRenderer.material.mainTexture.width, meshRenderer.material.mainTexture.height, TextureFormat.RGBA32, false);
        texture.filterMode = FilterMode.Point;
        texture.wrapMode = TextureWrapMode.Clamp;
        texture.SetPixels(((Texture2D)meshRenderer.material.mainTexture).GetPixels());
        texture.Apply();

        meshRenderer.material.mainTexture = texture;

        for (int y = 0; y < 200; y++)
        {
            for (int x = 0; x < 800; x++)
            {
                texture.SetPixel(x, y, Color.clear);
            }
        }

        texture.SetPixel(0, 0, Color.red);
        texture.SetPixel(1, 0, Color.red);
        texture.SetPixel(2, 0, Color.red);

        texture.Apply();

And below the results:

7574686--938323--Unity_Qd0x7B3nLW.png
7574686--938323--Unity_Qd0x7B3nLW.png684×885 4.01 KB

Many thanks for your help!!!