size(400, 400, P3D);
noStroke();
PImage img = loadImage("shells.jpg");
textureMode(NORMAL); 
beginShape();
texture(img);
vertex(40, 80, 0, 0);
vertex(320, 20, 1, 0);
vertex(380, 360, 1, 1);
vertex(160, 380, 0, 1);
endShape();