Working in 3ds Max
When building content within 3ds Max, or after importing content using COLLADA or FBX, it is important to go over a few things in order to make sure your model is setup properly. 3ds Max includes a range of features that give the user great freedom and power to create some amazing meshes and materials. It is important, then, that Sirikata is able to understand the choices the user has made and display them correctly. This article will go over some of the steps and processes you should do before exporting your mesh for use in engine.
Similar to Harden/Soften Normals in Maya, the Smoothing Groups feature in 3ds Max determines whether the edge of an object is hard, like the edge of a table, or soft, like the edge of a pillow. Select your object and click the drop down icon next to “Editable Poly” in the Modify tab. Select “Polygon.” Navigate to the “Polygon Properties” section and drop the menu to find “Smoothing Groups.” Set up your smoothing groups accordingly, or if you are importing using COLLADA, make sure that your smoothing groups have transferred over correctly from the program you originally modeled in. This model only has 1 smoothing group, because it is completely hard edged.
If your object needs to have more than one material applied to it (for example, a window: 1 material for glass, 1 material for the wood frame). The Material IDs section is located right above the Smoothing Groups, under “Polygon Properties” section. The model I am working with, tree_ash01, only has one material ID because it only needs one – the leaves and bark do not require separate materials because they would have the exact same material set up. There isn’t a hard limit, but try and have less than 6 material IDs per object. You are welcome to try as many as you would like on an object.
Whether you have imported your file using COLLADA or you started off in 3ds Max, it is important that your object maintains the name throughout its creation. In order to name your mesh, go to the Modify panel. The top input area is your mesh’s name. Change it accordingly.
NOTE: Naming is important as the end folder to which Ogre exports your mesh to must be named the same as the mesh (in the case of my mesh, the folder would be /tree_ash01/ if the mesh is named tree_ash01).
Map Channels and Multiple UV Sets
For more advanced meshes and materials, multiple UV sets may be required. Unfortunately, 3ds Max has trouble keeping track of multiple UV sets, or, as it refers to them, Map Channels. If you’ve imported from Maya using COLLADA, you may want to go through this process just in case. Go to the Modify tab and apply an “Unwrap UVW” modifier. Create your basic UV and make sure that the Map Channel is set to 1.
Now click “Save…” and save your UV out as map1.uvw. Now, right click on the “Unwrap UVW” and select “Collapse All.” Confirm and you should only see Editable Poly left on the Modify tab. Now, apply another “Unwrap UVW” modifier and make sure you change Map Channel to 2. Now, choose “Load…” and select the .uvw file you saved out. Edit the UV as you see fit. You will be applying specific textures to each UV later.
- Map Channel #1: 0 to 1 textures
- Map Channel #2: Tileable textures.
- Map Channel #3: Grunge maps