//imports an obj from a filePath and return a Geometry
func ImportObj(filePath string) (geometry *renderer.Geometry, material *renderer.Material, err error) {
obj := &objData{Indicies: make([]uint32, 0, 0), Vertices: make([]float32, 0, 0)}
vertexList := make([]float32, 0, 0)
uvList := make([]float32, 0, 0)
normalList := make([]float32, 0, 0)
//split the file name from the file path
filePathTokens := strings.Split(strings.Replace(filePath, "\\", "/", -1), "/")
fileName := filePathTokens[len(filePathTokens)-1]
path := strings.TrimRight(filePath, fileName)
//open the file and read all lines
file, err := os.Open(filePath)
if err != nil {
fmt.Printf("Error opening geometry file: %v\n", err)
return
}
defer file.Close()
var mtlErr error
scanner := bufio.NewScanner(file)
for scanner.Scan() {
line := scanner.Text()
tokens := strings.Fields(line)
if len(tokens) > 0 {
dataType := tokens[0]
if dataType == "o" { //sub mesh
obj.Name = tokens[1]
} else if dataType == "v" { //xyz vertex
vertexList = append(vertexList, stf(tokens[1]), stf(tokens[2]), stf(tokens[3]))
} else if dataType == "vt" { //uv coord
uvList = append(uvList, stf(tokens[1]), stf(tokens[2]))
} else if dataType == "vn" { //xyz vertex normal
normalList = append(normalList, stf(tokens[1]), stf(tokens[2]), stf(tokens[3]))
} else if dataType == "f" { // v/t/n face
obj.processFace(line, vertexList, uvList, normalList)
} else if dataType == "mtllib" {
obj.Mtl, mtlErr = importMTL(path, tokens[1])
} else if dataType == "usemtl" { //mtl material
//TODO: multiple mtls
}
}
}
geometry = renderer.CreateGeometry(obj.Indicies, obj.Vertices)
if mtlErr == nil && obj.Mtl != nil {
textures := []*renderer.Texture{}
for key, img := range obj.Mtl.maps {
textures = append(textures, renderer.NewTexture(key, img, true))
}
material = renderer.NewMaterial(textures...)
}
if err = scanner.Err(); err != nil {
fmt.Printf("Error loading geometry: %v\n", err)
return
}
return
}
func CreateParticleSystem(settings ParticleSettings) *ParticleSystem {
geometry := renderer.CreateGeometry(make([]uint32, 0, 0), make([]float32, 0, 0))
node := renderer.NewNode()
node.Add(geometry)
ps := ParticleSystem{
Settings: settings,
FaceCamera: true,
Node: node,
geometry: geometry,
particles: make([]*Particle, settings.MaxParticles),
}
ps.initParitcles()
return &ps
}