Troubleshooting Glass Collisions

Setting up object properties

Collision IDs are assigned to the collision object under Properties > General > External State > ID in polygon mode.

Since ZModeler 3.1.5, collision IDs and properties and they can simply be selected with the Properties > GTA V > Options tool in polygon mode. If this tool is not available, make sure to select the correct compatibility settings as explained in the ZModeler forums.

Using this tool, set the following attributes and choose the correct window type:

CAR_GLASS_STRONG (ID 122) is used for the front windscreen, CAR_GLASS_MEDIUM (ID 121) for the rear windscreen and CAR_GLASS_WEAK (ID 120) for the side/door windows and lightbar lenses.

Setting up the user-defined options

Other than the "E" and "Mass" fields, an additional "Crash" (with no assigned value) field must be added too to the object's properties.

Additionally, a common mistake is not to add the "Crash" field to the user-defined options of the materials assigned to that glass object too.

Glass objects & layers

The game uses the L1 LOD to display broken glass, it is therefore always necessary to have at least an L0 and L1 object.

Glass should always have an outer and inner layer, the outer laying being assigned to a normal vehicle_vehglass shader and the inner being assigned to a vehicle_vehglass_inner shader. This inner layer is merely a copy of the outer layer with the normals flipped towards the inside of the model. In terms of naming though, I recommend that you name your glass parts according to the names used on generic models. For lightbars, make use of "siren_glass1", "siren_glass2", and "siren_glass3" with their respective "siren_glass# [COL]" meshes compound under the parent.