Tool to display LightWave 3D objects.
LightWave 3D is a 3D modelling and rendering application that used to be popular some time ago, but I still have a small collection of object files from that era that I wanted to quickly view without importing them into something more complicated like Unity or some conversion app. Thus, the LightWave Object Viewer was born.
LightWave Object Viewer is a Windows application using Direct3D 11, created in Visual Studio.
Compile and run the tool, and then you can simply drag and drop a LightWave object (LWO) file onto the window to display it.
Alternatively, load an object by specifying its full pathname as a parameter on the command line, e.g.:
LightWaveObjectViewer.exe C:\MyObjects\MyCoolObject.lwo
You can also create a file association using this method, so that LightWave objects can be viewed by double clicking them in Windows Explorer.
- Add ability to load objects using command line (for file associations)
- Add prelminary support for LWO3 object format
- Apply vertex color from surface definition
- Added object rotation by dragging the 3D view using the mouse.
- Added support for polygons with greater than 4 sides.
- Added support for changing the view distance using the mouse wheel.
The viewer tool was written in C++ using the Win32 API for the base application and the Direct3D 11 API for the 3D parts.
The object file parsing was written entirely based on official LightWave 3D object file format documentation available online (as of this writing). This is my own interpretation of the file format, so errors are entirely possible. I'll squash any bugs that I find, but my collection of LightWave 3D objects is small and I don't have the software anymore to create new ones (hence this viewer).
The file format uses a chunk-style organization, not unlike the block format found in MP3 ID3v2 files. I currently skip over most chunk types but will support more in the future.
LightWave 3D uses n-sided polygons, so I've implemented a generalized algorithm to split any polygon with more than 3 vertices into triangle strips. The normal vector is being calculated at each vertex since LightWave doesn't include the normals as part of the file.
For the moment I'm splitting shared vertices into separate ones except for n-sided faces, but this is definitely something that I want to look at in a bit more depth, i.e. for interpolated normals
The viewer uses a simple and typical Direct3D 11 rendering strategy, using index and vertex buffers to render triangles.
Transformation matrices are passed to the shaders using constant buffers, with vertex and normal transformations taking place in the vertex shader, and lighting calculations done in the pixel shader. At this early stage, the lighting is simply a diffuse Lambert shading model with ambient lighting, but without the specular component, i.e.:
Ir = ka Ia + kd Ii · (n · l)
Adding other components such as specular reflections and texturing should be straightforward, and I'd guess most of the work will be on the file parsing side rather than D3D.
Some improvements I'd like to make next, in rough priority order:
- Handle more LightWave surface attributes (e.g. reflectivity, etc) and improve the shader.
- Additional UI to tweak the display.
- Test on a wider range of objects.