Compound Bodies

The Skull as a Compound Body

Expand The skull is an interesting shape to try to turn into a compound body, and you can see it in all its magnificence here: Skull As A Compound Body

It is roughly composed of a sphere for most of it, with a box around the jaw area. A bit of work is needed to position the sphere and box as well as possible. The skull is compounded from these two covering meshes.

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Note Center of mass is at the origin of the compound object.

Compound to Empty Mesh

1. Create an empty mesh to be used as a parent for the compound body;
2. Create a range of appropriately shaped standard meshes to fit over the irregular mesh;
3. Parent the standard meshes and the irregular mesh to the empty mesh;
4. Calculate or estimate the mass for each standard mesh;
5. Create physics impostors for each standard mesh with zero mass;
6. Create a physics impostor for the empty mesh, using the NoImpostor property, with the total mass of all the standard meshes.

Note Step 3 MUST come before step 4 and step 5 before step 6.

Skull As A Compound Body 1

Compound Covering Meshes to The Complex Mesh

1. Create a range of appropriately shaped standard meshes to fit over the irregular mesh;
2. Parent the standard meshes to the irregular mesh;
3. Calculate or estimate the mass for each standard mesh;
4. Create physics impostors for each standard mesh with zero mass;
5. Create a physics impostor for the irregular mesh, using the NoImpostor property, with the total mass of all the standard meshes.

Note Steps 2, 4 and 5 must be in that order.

Skull As A Compound Body 2

Compound to One of the Covering Meshes

1. Create a range of appropriately shaped standard meshes to fit over the irregular mesh;
2. Choose one standard mesh and parent the other standard meshes and the irregular mesh to this mesh;
3. Calculate or estimate the mass for each standard mesh;
4. Create physics impostors for each standard mesh with the assumed mass;

Note Step 2 MUST come before step 4.

Skull As A Compound Body 3

Further reading