diff --git a/struct.go b/struct.go
index 1b6e903..efb1d58 100644
--- a/struct.go
+++ b/struct.go
@@ -504,11 +504,6 @@ func (n *NormalTexture) MarshalJSON() ([]byte, error) {
 	return out, err
 }
 
-// NewOcclusionTexture returns a default OcclusionTexture.
-func NewOcclusionTexture(index int32) *OcclusionTexture {
-	return &OcclusionTexture{Index: index, Strength: 1}
-}
-
 // An OcclusionTexture references to an occlusion texture
 type OcclusionTexture struct {
 	Extensions Extensions  `json:"extensions,omitempty"`
@@ -518,6 +513,11 @@ type OcclusionTexture struct {
 	Strength   float64     `json:"strength" validate:"gte=0,lte=1"`
 }
 
+// NewOcclusionTexture returns a default OcclusionTexture.
+func NewOcclusionTexture(index int32) *OcclusionTexture {
+	return &OcclusionTexture{Index: index, Strength: 1}
+}
+
 // UnmarshalJSON unmarshal the texture info with the correct default values.
 func (o *OcclusionTexture) UnmarshalJSON(data []byte) error {
 	type alias OcclusionTexture
@@ -537,8 +537,8 @@ func (o *OcclusionTexture) MarshalJSON() ([]byte, error) {
 		if o.Index == -1 {
 			out = removeProperty([]byte(`"index":-1`), out)
 		}
-		if o.Strength == -1 {
-			out = removeProperty([]byte(`"strength":-1`), out)
+		if o.Strength == 1 {
+			out = removeProperty([]byte(`"strength":1`), out)
 		}
 		out = sanitizeJSON(out)
 	}
@@ -577,11 +577,11 @@ func (p *PBRMetallicRoughness) MarshalJSON() ([]byte, error) {
 	type alias PBRMetallicRoughness
 	out, err := json.Marshal(&struct{ *alias }{alias: (*alias)(p)})
 	if err == nil {
-		if p.MetallicFactor == -1 {
-			out = removeProperty([]byte(`"metallicFactor":-1`), out)
+		if p.MetallicFactor == 1 {
+			out = removeProperty([]byte(`"metallicFactor":1`), out)
 		}
-		if p.RoughnessFactor == -1 {
-			out = removeProperty([]byte(`"roughnessFactor":-1`), out)
+		if p.RoughnessFactor == 1 {
+			out = removeProperty([]byte(`"roughnessFactor":1`), out)
 		}
 		if p.BaseColorFactor == [4]float64{1, 1, 1, 1} {
 			out = removeProperty([]byte(`"baseColorFactor":[1,1,1,1]`), out)
diff --git a/struct_test.go b/struct_test.go
index cbac045..2bb74fc 100644
--- a/struct_test.go
+++ b/struct_test.go
@@ -785,9 +785,9 @@ func TestOcclusionTexture_MarshalJSON(t *testing.T) {
 		want    []byte
 		wantErr bool
 	}{
-		{"default", &OcclusionTexture{Index: -1, Strength: -1}, []byte(`{}`), false},
+		{"default", &OcclusionTexture{Index: -1, Strength: 1}, []byte(`{}`), false},
 		{"empty", &OcclusionTexture{Index: 0, Strength: 0}, []byte(`{"index":0,"strength":0}`), false},
-		{"nodefault", &OcclusionTexture{Index: 1, Strength: 1}, []byte(`{"index":1,"strength":1}`), false},
+		{"nodefault", &OcclusionTexture{Index: 1, Strength: 0.5}, []byte(`{"index":1,"strength":0.5}`), false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -810,9 +810,9 @@ func TestPBRMetallicRoughness_MarshalJSON(t *testing.T) {
 		want    []byte
 		wantErr bool
 	}{
-		{"default", &PBRMetallicRoughness{MetallicFactor: -1, RoughnessFactor: -1, BaseColorFactor: [4]float64{1, 1, 1, 1}}, []byte(`{}`), false},
+		{"default", &PBRMetallicRoughness{MetallicFactor: 1, RoughnessFactor: 1, BaseColorFactor: [4]float64{1, 1, 1, 1}}, []byte(`{}`), false},
 		{"empty", &PBRMetallicRoughness{MetallicFactor: 0, RoughnessFactor: 0, BaseColorFactor: [4]float64{0, 0, 0, 0}}, []byte(`{"baseColorFactor":[0,0,0,0],"metallicFactor":0,"roughnessFactor":0}`), false},
-		{"nodefault", &PBRMetallicRoughness{MetallicFactor: 1, RoughnessFactor: 1, BaseColorFactor: [4]float64{1, 0.5, 1, 1}}, []byte(`{"baseColorFactor":[1,0.5,1,1],"metallicFactor":1,"roughnessFactor":1}`), false},
+		{"nodefault", &PBRMetallicRoughness{MetallicFactor: 0.5, RoughnessFactor: 0.5, BaseColorFactor: [4]float64{1, 0.5, 1, 1}}, []byte(`{"baseColorFactor":[1,0.5,1,1],"metallicFactor":0.5,"roughnessFactor":0.5}`), false},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {