Creating 3D Game Art for the iPhone with Unity Part 5 pot

Remember, importing to Unity iOS is the goal, and it’s best to match all of

your 3D objects to Unity’s default scale.

Ok, we’ve established that Blender objects are twice as large as Unity iOS

objects and we need to adjust the Scale Factor to 0.5 upon import; however,

there’s a caveat to this setting when working with modo objects exported

from Blender. Remember that our modo objects are twice as small as Blender

objects. If we export our modo-created objects from Blender, then the 0.5

Scale Factor will now become incorrect. Because modo objects are twice

as small as Blender objects, the process of importing and working with the

modo object from Blender acts as a “prescaling operation” when we export

the modo-created object from Blender, it will already be scaled twice as

small and we can then simply set the Scale Factor in the FBX Importer to 1.0

upon importing into Unity iOS. In Fig. 5.3, you can see a modo-created cube

exported from Blender and that it matches the default Unity iOS cube’s scale

exactly with a Scale Factor of 1.0.

So now, we have the correct workflow for sizing our Blender and modo

objects to perfectly match the default Unity iOS scale. You can see the proper

settings in the chart in Fig. 5.4.

Unity iOS Blender Support and FBX Workflow

In regards to Blender animation, Unity iOS supports all nodes with position,

rotation, and scale. Pivot points, you set in Blender, as well as object names

are also imported. Blender’s Bones and Skinned Mesh Animation are also

supported.

Using FBX

Unity iOS will import a “.blender” file and convert it on the back end using

the Blender FBX Importer. However, this is not the workflow that I use with

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Creating 3D Game Art for the iPhone with Unity

FIG 5.3 Show Modo-Created Cube

Being Same Size as Unity iOS Cube

at1.0 Scale Factor.

Blender and Unity iOS. Instead, I prefer to export the FBX from Blender. The

reason being is mainly personal preference. In my day-to-day work, I mainly

work with modo, Maya, Motion Builder, and Mudbox and have long estab￾lished FBX to be the best method for sending objects through my pipeline.

I like having the FBX intermediate file available in case I need to take it into

another application and it stops me from having to open Blender to create an

FBX file in these cases.

A major issue I have with Blender is the inability to import an FBX file. Luckily,

I am only using Blender for character animation and this doesn’t pose a huge

problem, but it does make me add an extra step to my pipeline, which is to

export, and OBJ from modo. Once Tater was ready for rigging, I exported an

OBJ from modo so that I could get the model into Blender for rigging and

animation. A big issue with OBJ files is that they only support one UV set.

However, since my character doesn’t contain overlapping UVs and typically,

a character won’t, I only needed 1 UV set. As you’ll recall from Chapter 4, when

creating the level, we needed to have a separate UV because we were using

overlapping UVs for tiling. You can’t correctly create lightmaps with overlap￾ping UVs. With Tater, I didn’t use a lightmap shader in Unity iOS and thus didn’t

need the second UV set. Instead, I baked the lightmap into the diffuse texture

map as shown in Fig. 5.5.

Baking the lightmap into the diffuse texture map is not only a solution to

my multiple UV set issue with OBJ but it’s also a viable solution overall in

regards to reducing texture memory. Instead of using a lightmap shader in

Unity iOS, you can just use a vertex lit shader and one diffuse texture map

as shown in Fig. 5.6. This effectively reduces the number of texture maps

needed for Tater.

The complete workflow for the Tater 3D assets is shown in the chart

in Fig. 5.7.

FIG 5.4 Here You Can See a Chart

that Shows the Different Scale Factor

Settings.

Blender and Collada

Besides the OBJ format,

you can also utilize a

Collada pipeline between

Blender and modo since

both apps can read and

write the Collada format.

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Animation Using Blender