Sandbag Physics

if anyone knows anything about Blender 2.6’s Physics, Cloth making, and partical making please help me out and try to answer this question. i am trying to make a sandbag. easy enough right? well see i want it to be as realistic as possible, and im wanting to make sand (particle effect) inside the bag (cloth) but i do not want the sandbag to be flopping around if an object was to colide with it. im wanting the bag to move, aswell as the sand inside. so lets say you were to punch the bag, the cloth moves inward and the sand moves with it (inside of the bag) its the same concept as if you were to take a bag filled with sand and drop it; what happens in that situation is what i am aiming for. i want the sandbag to haave gravity physics and a realistic effect to having it fall or bend. what i mean by bend is, lets say you take that sandbag(filled with sand) and you lean it up against a wall. you can see it bend. same thing if you lay it on a rock, the sandbag bends in the direction of the ground. If anyone knows what i am talking about and knows how to do these physics, making the Cloth for the bag, and particle effects please HELP ME :slight_smile: thanks

Although it won’t be physically accurate as far as cloth and sand particles shearing across each other goes, I would think you could get close to those effect by using soft bodies (one soft body for each sand bag). You need to read up on them a bit, then pay attention to the way you subdivide the mesh (bag). There are settings that would let you control how much the bag deforms when, for example, it is dropped on the floor (“Bend”), and also settings (“Plastic”) that determine whether the bag (soft body) recovers its original shape. Watch this excellent video by Daniel Kreuter:

Physics in Blender is rather limited. You can make things bang into each other within certain limits… and that’s it. For a sandbag, you should rather look in the direction of the soft bodies.

Keep some time to study the particle hair too because you’re gonna lose some… hair. :wink:

(Edit: Dave beat me on the finish line.)