Method LoadAnimation

loader/gltf/loader.go:328–391

LoadAnimation creates an Animation for the specified animation index from the GLTF Animations array.

(animIdx int)

// LoadAnimation creates an Animation for the specified
// animation index from the GLTF Animations array.
func (g *GLTF) LoadAnimation(animIdx int) (*animation.Animation, error) {

	// Check if provided animation index is valid
	if animIdx < 0 || animIdx >= len(g.Animations) {
		return nil, fmt.Errorf("invalid animation index")
	}
	log.Debug("Loading Animation %d", animIdx)
	animData := g.Animations[animIdx]

	anim := animation.NewAnimation()
	anim.SetName(animData.Name)
	for i := 0; i < len(animData.Channels); i++ {

		chData := animData.Channels[i]
		target := chData.Target
		sampler := animData.Samplers[chData.Sampler]
		node, err := g.LoadNode(target.Node)
		if err != nil {
			return nil, err
		}

		var validTypes []string
		var validComponentTypes []int

		var ch animation.IChannel
		if target.Path == "translation" {
			validTypes = []string{VEC3}
			validComponentTypes = []int{FLOAT}
			ch = animation.NewPositionChannel(node)
		} else if target.Path == "rotation" {
			validTypes = []string{VEC4}
			validComponentTypes = []int{FLOAT, BYTE, UNSIGNED_BYTE, SHORT, UNSIGNED_SHORT}
			ch = animation.NewRotationChannel(node)
		} else if target.Path == "scale" {
			validTypes = []string{VEC3}
			validComponentTypes = []int{FLOAT}
			ch = animation.NewScaleChannel(node)
		} else if target.Path == "weights" {
			validTypes = []string{SCALAR}
			validComponentTypes = []int{FLOAT, BYTE, UNSIGNED_BYTE, SHORT, UNSIGNED_SHORT}
			children := node.GetNode().Children()
			if len(children) > 1 {
				return nil, fmt.Errorf("animating meshes with more than a single primitive is not supported")
			}
			morphGeom := children[0].(graphic.IGraphic).IGeometry().(*geometry.MorphGeometry)
			ch = animation.NewMorphChannel(morphGeom)
		}

		// TODO what if Input and Output accessors are interleaved? probably de-interleave in these 2 cases

		keyframes, err := g.loadAccessorF32(sampler.Input, "Input", []string{SCALAR}, []int{FLOAT})
		if err != nil {
			return nil, err
		}
		values, err := g.loadAccessorF32(sampler.Output, "Output", validTypes, validComponentTypes)
		if err != nil {
			return nil, err
		}