   Dragging part of an image
  I have Microsoft''s Picture It! software and it allows you to grab a point on a picture and drag it around.Does anyone here know how I might be able to accomplish this myself? 
  on mousedown event:obtain x and y from mouse.find out which point is closest to that and store it''s id.set a global flag indicating "dragging" is true.on mousemove event:if "dragging" is true, AND if the id has a value >= 0, set the x and z (or whatever you want) of the point stored in the id to the x and y value of the mouse (maybe transform them, depending on the mode you are in (glOrtho?))on mouseup event:set "dragging" to falseset id to e.g. -1, indicating no point is selected for dragging (optional) ;  Sorry I wasn''t perfectly clear there. I don''t mean the whole picture, I mean drag a small part of the picture to distort it ;  Try something likedraw picture as texture on high density gridselect start pointselect end pointget drag direction vectorscale down direction vector by something like    dx = dx / picture_width;    dy = dy / picture_height;for each vertex on grid    get distance from start point    if the vertex is in range of tool (it has some kind of too_radius)   use some gaussina or sinus based function to calculate force based on radius. something like force = cos( radius / tool_radius * Pi * 0.5f );   apply (force * direction vector) to texture coordinatesrepeat   You should never let your fears become the boundaries of your dreams. [edited by - _DarkWIng_ on February 5, 2004 3:37:16 AM]