Car_graphics.md

Cars in VDrift are composed of multiple components. Their graphical representation consists of geometry(mesh), textures and a draw flag which denotes whether the object is to be handled as opaque, transparent or emissive. The setup is done in car parameters files .car.

Geometry(meshes) can share textures. The number of meshes and textures should be kept low for performance reasons.

Example of a graphical component setup:

[some_car_part]
texture = diffuse.png, misc1.png, misc2.png  # (required) the first texture(diffuse.png) is required, additional textures(misc1.png, misc2.png)are optional
mesh = model.joe                             # (required) geometry (mesh)
position = 0.736, 1.14, -0.47                # (optional) relative mesh position
rotation = 0, 0, 30                          # (optional) relative mesh orientation 
scale = -1, 1, 1                             # (optional) mesh scale factor
color = 0.8, 0.1, 0.1                        # (optional) base diffuse color; blended with diffuse texture using alpha channel as mask
draw = transparent                           # (optional) draw flag: opaque, transparent, emissive; opaque is default

Geometry

Car geometry is stored in VDrift native JOE format. Import/export scripts for Blender are available here: https://github.com/VDrift/blender-scripts

Shared Geometry

When loading a mesh VDrift first checks cars/ directory and then falls back to the carparts (and trackparts) directory. The assets in this directory are shared, can be used by all cars.

Generated Geometry

Car tire geometry [wheel..tire] (with id = {fl, fr, rl, rr}) will be auto-generated when no mesh is provided. The dimensions are derived from the provided tire parameters.

[wheel.fl.tire]
texture = tire.png        # (optional) enables auto-generated tire mesh
mesh = tire.joe           # (optional) overrides auto-generated tire mesh

Car brake geometry [wheel..brake] will be auto-generated from brake dimensions when no mesh is provided.

[wheel.fl.brake]
texture = brake_disk.png  # (optional) enables auto-generated disk mesh
mesh = brake_disk.joe     # (optional) overrides auto-generated brake disk mesh

Car wheel [wheel.] mesh contains only the wheel disc at unit size (0.5 m radius). The rim is auto-generated from tire dimensions. The disk mesh is scaled to fit it. To be able to use a custom wheel mesh (which already has a rim) the property genrim has to be set to false.

[wheel.fl]
texture = wheel.png       # (required) wheel (disk + rim) diffuse texture
mesh = wheel.joe          # (required) wheel disk mesh; if genrim=false wheel mesh with rim
genrim = false            # (optional) enable auto-generated wheel rim and scaling; default true

Textures

VDrift supports multi-texturing for more realistic geometry surface graphics. Texture are RGBA images in PNG format. As of April 2013 DDS(DXT1-3) is also supported.

• 1. Texture (required): Diffuse color (diffuse albedo or diffuse reflectance) in the RGB channels and Color Blending mask in the A channel.
• 2. Texture (optional): Specular reflection (fresnel reflection coeff at 0 deg) in the RGB channels and Glossiness (surface roughness) in the A channel.
• 3. Texture (optional): Normal map (tangent space normals) in the RGB channels.

Shared Textures

When loading a texture VDrift first looks for it in cars/ directory and then falls back to the carparts (and trackparts) directory.

Car Skins

The diffuse texture of the car [body] component can be swapped by the player against textures placed in /skins directory.

Category:Cars