Static Model via COLLADA¶
This tutorial shows how to get a static model from Blender to OpenMW using the COLLADA format. It does not cover using Blender itself, as there are many better resources for that. The focus is solely on the pipeline and its specific requirements. Static models are those that don’t have any animations included in the exported file.
To use the Blender to OpenMW pipeline via COLLADA, you will need the following.
The barrel shown in this tutorial, and its revelant files, are available from the Example Suite repository. This should be useful for further study of how to set up a static prop in case the tutorial is not clear on any particular thing.
data/meshes/the_barrel.dae– exported model
data/textures/the_barrel.dds– diffuse texture
data/textures/the_barrel_n.dds– normal map
data/textures/the_barrel_n.dds– specular map
source_assets/the_barrel.blend– source file configured as this tutorial specifies
Location, Rotation, Scale¶
First, let’s take a look at how the fundamental properties of a scene in Blender translate to a COLLADA model suitable for use in OpenMW. These apply the same to static and animated models.
Objects keep their visual location and origin they had in the original scene.
- Blender’s +Z axis is up axis in OpenMW
- Blender’s +Y axis is front axis in OpenMW
- Blender’s X axis is left-right axis in OpenMW
Scale ratio between Blender and OpenMW is 70 to 1. This means 70 units in Blender translate to 1 m in OpenMW.
However, a scale factor like this is impractical to work with. A better approach is to work with a scale of 1 Blender unit = 1 m and apply the 70 scale factor at export. The exporter will automatically scale all object, mesh, armature and animation data.
OpenMW uses the classic, specular material setup and currently doesn’t
support the more mainstream PBR
way. In Blender, the mesh needs a default material with a diffuse texture
connected to the
Base Color socket. This is enough for the material to be
included in the exported COLLADA file.
Additional texture types, such as specular or normal maps, are used
when enabled in the OpenMW Launcher with the
Auto use object normal maps
Auto use object specular maps options. The textures need to follow the
name of the diffuse texture with an additional suffix, and be in the same
folder. OpenMW will then automatically recognize and use these textures. In the
case of the barrel, the textures are named:
the_barrel.dds- diffuse texture
the_barrel_n.dds- normal map
the_barrel_spec.dds- specular map
In Blender, a custom collision shape is set up with an empty named
collision. Any mesh that is a child of this empty will be
used for physics collision and will not be visible in-game. There can be
multiple child meshes under
collision and they will all contribute to the
collision shapes. The meshes themselves can have an arbitrary name, it’s only
the name of the empty that is important. The
tcb command in OpenMW’s in-game
console will make the collision shapes visible and you will be able to inspect
If no custom collision shape is present, OpenMW will use the regular mesh itself, which is not optimal and should be avoided.
For static models, use the following exporter settings. Before export, select all objects you wish to include in the exported file and have the “Selected Objects” option enabled. Without this, the exporter could fail.
Getting the Model in-game¶
Once the model is exported, it needs to be placed in the correct folder where OpenMW will read it. In OpenMW-CS it can then be assigned to an object and added to a world cell.