Collision Hulls in 3ds Max for Source
A collision hull (also known as a collision mesh or simply hull) is a simplified version of your model that is used for collision detection. By being a simplified version of the model, it saves the game engine all the effort of detecting collisions on complex shapes.
Things To Know
- Collision hulls must be Convex.
- If your model is complex and cannot be realistically wrapped in a single convex shape, then the hull must be separate convex pieces.
- If your hull is composed of multiple pieces, and each piece is an Element sub-object of a single mesh, then each element must have a unique smoothing group (that other elements in the hull do not share).
- For multi-part hulls, your model QC file must have the $concave parameter.
Making a Collision Model
This page details making a hull using Wall Worm Model Tools and the Quick Hull feature.
- For each segment of the model that needs a hull, Detach it into its own element (or object*)
- Assign your mesh(es) to a WWMT Helper
- Press the Quick Hull button
- The $concave flag is automatically set
- Each Element of each mesh in your model will get a hull made from it
- Each hull will get a unique smoothing group
- All hulls are automatically assigned as hulls in the WWMT Helper
- *Any piece of the model that is broken into a separate Object (as opposed to Element) with the Editable Poly Detach function is no longer part of the model and must be re-assigned to the WWMT helper with the Add Sel or Append functions before the Quick Hull Function is run.
- If your model is animated, you will need to skin the hull.
- Also see Hull Helper.
WWMT Collision Hull Utilities & Techniques
If you do not have Convexity and access to the Quick Hull button, you still have several tools in WWMT to optimize the process of making a hull.
- Auto Hull
If your model is simple, you can tell the Valve model compiler to generate a hull by clicking the Auto Hull button in the Collision Model & Physics Rollout.
This function does not work in conjunction with $concave.
This function does not work with animated models.
- Prepare CM
This function lets you choose a mesh and apply proper smoothing groups and textures. Read More.
- Process CM
This function will apply proper smoothing groups to all hulls assigned to the current WWMT helper and give a texture. Read More.
- Using WWMT
Articles on using the Wall Worm Model Tools.
- Making Collision Models