Texture2D.GetPixelBilinear

Description

Returns filtered pixel color at normalized coordinates (u, v).

Coordinates u and v go from 0.0 to 1.0, just like UV coordinates in meshes. If coordinates are out of bounds (larger than 1.0 or smaller than 0.0), they will be clamped or repeated based on the texture's wrap mode.

Texture coordinates start at lower left corner. UV of (0,0) lands exactly on the bottom left texel; and UV of ((width-1)/width, (height-1)/height) lands exactly on the top right texel.

Returned pixel color is bilinearly filtered.

The texture must have the Read/Write Enabled flag set in the import settings, otherwise this function will fail. GetPixelBilinear is not available on Textures using Crunch texture compression.

See Also: GetPixel.

// "Warp" a texture by squashing its pixels to one side.
// This involves sampling the image at non-integer pixel
// positions to ensure a smooth effect.

// Source image.
var sourceTex: Texture2D;

// Amount of "warping".
var warpFactor = 1.0;

private var destTex: Texture2D;
private var destPix: Color[];


function Start () {
    // Set up a new texture with the same dimensions as the original.
    destTex = new Texture2D(sourceTex.width, sourceTex.height);
    destPix = new Color[destTex.width * destTex.height];

    // For each pixel in the destination texture...
    for (var y = 0; y < destTex.height; y++) {
        for (var x = 0; x < destTex.width; x++) {
            // Calculate the fraction of the way across the image
            // that this pixel positon corresponds to.
            var xFrac = x * 1.0 / (destTex.width - 1);
            var yFrac = y * 1.0 / (destTex.height - 1);

            // Take the fractions (0..1)and raise them to a power to apply
            // the distortion.
            var warpXFrac = Mathf.Pow(xFrac, warpFactor);
            var warpYFrac = Mathf.Pow(yFrac, warpFactor);

            // Get the non-integer pixel positions using GetPixelBilinear.
            destPix[y * destTex.width + x] = sourceTex.GetPixelBilinear(warpXFrac, warpYFrac);
        }
    }

    // Copy the pixel data to the destination texture and apply the change.
    destTex.SetPixels(destPix);
    destTex.Apply();

    // Set our object's texture to the newly warped image.
    GetComponent.<Renderer>().material.mainTexture = destTex;
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Texture2D sourceTex;
    public float warpFactor = 1.0F;
    private Texture2D destTex;
    private Color[] destPix;
    void Start() {
        destTex = new Texture2D(sourceTex.width, sourceTex.height);
        destPix = new Color[destTex.width * destTex.height];
        int y = 0;
        while (y < destTex.height) {
            int x = 0;
            while (x < destTex.width) {
                float xFrac = x * 1.0F / (destTex.width - 1);
                float yFrac = y * 1.0F / (destTex.height - 1);
                float warpXFrac = Mathf.Pow(xFrac, warpFactor);
                float warpYFrac = Mathf.Pow(yFrac, warpFactor);
                destPix[y * destTex.width + x] = sourceTex.GetPixelBilinear(warpXFrac, warpYFrac);
                x++;
            }
            y++;
        }
        destTex.SetPixels(destPix);
        destTex.Apply();
        GetComponent<Renderer>().material.mainTexture = destTex;
    }
}

See Also: GetPixel.