Separating Out Grass Meshes When Creating a Custom UCX Collision Mesh

This tutorial will teach you how to separate out grass meshes (and other non-solid objects) from the environment when creating a custom UCX collision mesh for use in Unreal Engine 4. The purpose of doing this is so that if you want to convert FFXI's graphical meshes into a collision mesh instead of using FFXI's official collision meshes for whatever reason (such as enhanced collision accuracy or getting rid of invisible walls), grass objects won't become solid blocks (like they are in this video), but rather will allow the player to pass right through them like in the official version of the game. Also, removing the grass objects from the rest of the environment and importing them as their own separate object gives us the ability to make them subject to wind dynamics,which improves the player's sense of immersion in the game world. We will be using 3Ds Max for this tutorial. Another tutorial on how to do the same thing in Maya will be posted at a later date.

Tutorial by Evenger, edited and expanded by Rhianu

Step 1: Import your FBX file into 3Ds Max
I'm assuming here that you have already exported the zone you wanted from Noesis and saved it as an FBX file.

File → Import → Import...

Navigate to and select the zone FBX file which you exported using Noesis, and then click "Open" to import it.

Under the "Advanced Options" section in the FBX Import window, put a check mark in the checkbox labeled "Automatic" to ensure that unit scale is converted automatically.

Step 2: Separate and collapse the grass objects
Select the item you wish to separate. Look for the matching names on the list to select them faster. This can be done with any object, but in this tutorial we're focusing on grass, so only select the grass objects.

Here I have all the grass selected. It is called "kusa," which is the Japanese word for "grass." ( 草 )

Once you have all the grass objects selected, hit the "Collapse Selected" button to combine all the grass meshes into one single mesh.

Step 3: Hide the new combined grass mesh
Click on the icon that looks like an eye to hide the grass mesh.

The grass objects should all become invisible (hidden) when they are disabled by toggling off their visibility via their corresponding eye icon.

Step 4: Delete all the other meshes
Delete everything in the scene except for the grass meshes.

Select All (Ctrl + A) → Delete

Your scene should now be completely empty (except for the grass mesh, which is still hidden).

Step 5: Unhide your hidden grass mesh and export
Unhide your combined grass object by toggling its visibility via the eye icon again.

Your grass objects should be the only thing left in the scene.

Finally, export your combined grass mesh.

File → Export → Export...

Save your grass mesh as an FBX file, and you're done! Just import it into your UE4 project and you should be good to go.