Merge pull request #4 from Patch2PDF/coordinate-system-fix

Jannik-Hm · web-flow · commit e32253992436 · 2026-03-11T14:56:24.000+01:00
Coordinate system fix
diff --git a/README.md b/README.md
@@ -18,7 +18,7 @@ See below for examples
 ```go
 RasterizerConfig{
   RenderLabels: false,
-  Rotation: rasterizer.Rotation{Alpha: 80, Beta: 0, Gamma: 200},
+  Rotation: rasterizer.Rotation{Alpha: 10, Beta: 0, Gamma: -20},
   OverrideColors: OverrideColorMap{},
   CanvasConfig: CanvasConfig{
 		Width:         4000,
@@ -37,7 +37,7 @@ RasterizerConfig{
 ```go
 RasterizerConfig{
   RenderLabels: true,
-  Rotation: rasterizer.Rotation{Alpha: 90, Beta: 0, Gamma: 180},
+  Rotation: rasterizer.Rotation{Alpha: 0, Beta: 0, Gamma: 0},
   OverrideColors: OverrideColorMap{},
   CanvasConfig: CanvasConfig{
 		Width:         4000,
diff --git a/examples/main.go b/examples/main.go
@@ -95,13 +95,13 @@ func main() {
 		LabelFontSize: 10,
 	}
 
-	rotation1 := MeshTypes.GenerateRotationMatrix(80, 0, 200)
+	rotation1 := MeshTypes.GenerateRotationMatrix(10, 0, -20)
 	canvas1, err := rasterizer.Draw(&stage_model, rasterizer.RasterizerConfig{RenderLabels: false, Rotation: rotation1, OverrideColors: overrideColors, CanvasConfig: canvasConfig})
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	rotation2 := MeshTypes.GenerateRotationMatrix(90, 0, 180)
+	rotation2 := MeshTypes.GenerateRotationMatrix(0, 0, 0)
 	rotation2 = rotation2.ReverseTransformation(rotation1)
 	rasterizer.SaveCanvasAsPNGFile("side.png", canvas1)
 	canvas2, err := rasterizer.Draw(&stage_model, rasterizer.RasterizerConfig{RenderLabels: true, Rotation: rotation2, OverrideColors: overrideColors, CanvasConfig: canvasConfig})
diff --git a/go.mod b/go.mod
@@ -5,10 +5,10 @@ go 1.25.6
 require (
 	github.com/Patch2PDF/GDTF-Mesh-Reader/v2 v2.2.0
 	github.com/Patch2PDF/GDTF-Parser v0.4.1
-	github.com/Patch2PDF/MVR-Parser v0.3.1
+	github.com/Patch2PDF/MVR-Parser v0.3.2
 )
 
-require golang.org/x/text v0.34.0 // indirect
+require golang.org/x/text v0.35.0 // indirect
 
 require (
 	github.com/qmuntal/gltf v0.28.0 // indirect
diff --git a/go.sum b/go.sum
@@ -2,8 +2,8 @@ github.com/Patch2PDF/GDTF-Mesh-Reader/v2 v2.2.0 h1:ykkdyTIl++IaxBbgo2WFF3/k4jy7I
 github.com/Patch2PDF/GDTF-Mesh-Reader/v2 v2.2.0/go.mod h1:zAcGHlYdE75hdFo624nQfQHTzw9+NfPJT8Eo2mB1lI8=
 github.com/Patch2PDF/GDTF-Parser v0.4.1 h1:RLmzQwIHGuEYc6C6hNtWA3HOpjhUizhkg36u0Px1a7E=
 github.com/Patch2PDF/GDTF-Parser v0.4.1/go.mod h1:2l8WWbsYr4D0Uo069HMh9tImKtaUzy2+OeUpl7IN+S4=
-github.com/Patch2PDF/MVR-Parser v0.3.1 h1:lg9MieoOL93Bm+huKz1yMlJWuFLzHyJ+afZj1S8UKbs=
-github.com/Patch2PDF/MVR-Parser v0.3.1/go.mod h1:2ekLlUhkPCkDli56afCQT/9EGdE/llx3NCF5E1+YiXc=
+github.com/Patch2PDF/MVR-Parser v0.3.2 h1:Kpq6BUs31KSUhLEg/f16gnRh1t5YD5Y94WeTo9NRGcY=
+github.com/Patch2PDF/MVR-Parser v0.3.2/go.mod h1:2ekLlUhkPCkDli56afCQT/9EGdE/llx3NCF5E1+YiXc=
 github.com/go-test/deep v1.0.1 h1:UQhStjbkDClarlmv0am7OXXO4/GaPdCGiUiMTvi28sg=
 github.com/go-test/deep v1.0.1/go.mod h1:wGDj63lr65AM2AQyKZd/NYHGb0R+1RLqB8NKt3aSFNA=
 github.com/qmuntal/gltf v0.28.0 h1:C4A1temWMPtcI2+qNfpfRq8FEJxoBGUN3ZZM8BCc+xU=
@@ -12,5 +12,5 @@ golang.org/x/image v0.36.0 h1:Iknbfm1afbgtwPTmHnS2gTM/6PPZfH+z2EFuOkSbqwc=
 golang.org/x/image v0.36.0/go.mod h1:YsWD2TyyGKiIX1kZlu9QfKIsQ4nAAK9bdgdrIsE7xy4=
 golang.org/x/sync v0.20.0 h1:e0PTpb7pjO8GAtTs2dQ6jYa5BWYlMuX047Dco/pItO4=
 golang.org/x/sync v0.20.0/go.mod h1:9xrNwdLfx4jkKbNva9FpL6vEN7evnE43NNNJQ2LF3+0=
-golang.org/x/text v0.34.0 h1:oL/Qq0Kdaqxa1KbNeMKwQq0reLCCaFtqu2eNuSeNHbk=
-golang.org/x/text v0.34.0/go.mod h1:homfLqTYRFyVYemLBFl5GgL/DWEiH5wcsQ5gSh1yziA=
+golang.org/x/text v0.35.0 h1:JOVx6vVDFokkpaq1AEptVzLTpDe9KGpj5tR4/X+ybL8=
+golang.org/x/text v0.35.0/go.mod h1:khi/HExzZJ2pGnjenulevKNX1W67CUy0AsXcNubPGCA=
diff --git a/model_manipulation.go b/model_manipulation.go
@@ -91,14 +91,16 @@ func normalizeAndRotateStageModel(canvas *Canvas, stageModel *StageModel, rotati
 	height := float64(canvas.height - 1)
 
 	// normalizing to canvas dimensions
-	diff := theoretical_max.Sub(theoretical_min)
-	scale := width / diff.X
-	if scale*diff.Y >= float64(canvas.height) {
-		scale = height / diff.Y
+	// NOTE: stagemodel coordinate system is z for up and x for right position
+	visualWidth := theoretical_max.X - theoretical_min.X
+	visualHeight := math.Abs(theoretical_max.Z - theoretical_min.Z)
+	scale := width / visualWidth
+	if scale*visualHeight > height {
+		scale = height / visualHeight
 	}
 	centeringMatrix = centeringMatrix.MulScalar(scale)
 	centeringMatrix.X03 += width / 2
-	centeringMatrix.X13 += height / 2
+	centeringMatrix.X23 -= height / 2
 
 	rotateAndTranslateStageModel(stageModel, centeringMatrix)
 }
diff --git a/triangle.go b/triangle.go
@@ -21,10 +21,11 @@ type Triangle struct {
 }
 
 func NewTriangleFromMeshTriangle(triangle MeshTypes.Triangle) Triangle {
+	// NOTE: mesh coordinate system is z for up and x for right position
 	return Triangle{
-		Point{x: math.Round(triangle.V0.Position.X), y: math.Round(triangle.V0.Position.Y), z: triangle.V0.Position.Z},
-		Point{x: math.Round(triangle.V1.Position.X), y: math.Round(triangle.V1.Position.Y), z: triangle.V1.Position.Z},
-		Point{x: math.Round(triangle.V2.Position.X), y: math.Round(triangle.V2.Position.Y), z: triangle.V2.Position.Z},
+		Point{x: (triangle.V0.Position.X), y: -(triangle.V0.Position.Z), z: -triangle.V0.Position.Y},
+		Point{x: (triangle.V1.Position.X), y: -(triangle.V1.Position.Z), z: -triangle.V1.Position.Y},
+		Point{x: (triangle.V2.Position.X), y: -(triangle.V2.Position.Z), z: -triangle.V2.Position.Y},
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -95,13 +95,13 @@ func main() {`
`95`	`95`	`LabelFontSize: 10,`
`96`	`96`	`}`
`97`	`97`
`98`		`- rotation1 := MeshTypes.GenerateRotationMatrix(80, 0, 200)`
	`98`	`+ rotation1 := MeshTypes.GenerateRotationMatrix(10, 0, -20)`
`99`	`99`	`canvas1, err := rasterizer.Draw(&stage_model, rasterizer.RasterizerConfig{RenderLabels: false, Rotation: rotation1, OverrideColors: overrideColors, CanvasConfig: canvasConfig})`
`100`	`100`	`if err != nil {`
`101`	`101`	`log.Fatal(err)`
`102`	`102`	`}`
`103`	`103`
`104`		`- rotation2 := MeshTypes.GenerateRotationMatrix(90, 0, 180)`
	`104`	`+ rotation2 := MeshTypes.GenerateRotationMatrix(0, 0, 0)`
`105`	`105`	`rotation2 = rotation2.ReverseTransformation(rotation1)`
`106`	`106`	`rasterizer.SaveCanvasAsPNGFile("side.png", canvas1)`
`107`	`107`	`canvas2, err := rasterizer.Draw(&stage_model, rasterizer.RasterizerConfig{RenderLabels: true, Rotation: rotation2, OverrideColors: overrideColors, CanvasConfig: canvasConfig})`
Original file line number	Diff line number	Diff line change
`@@ -21,10 +21,11 @@ type Triangle struct {`
`21`	`21`	`}`
`22`	`22`
`23`	`23`	`func NewTriangleFromMeshTriangle(triangle MeshTypes.Triangle) Triangle {`
	`24`	`+ // NOTE: mesh coordinate system is z for up and x for right position`
`24`	`25`	`return Triangle{`
`25`		`- Point{x: math.Round(triangle.V0.Position.X), y: math.Round(triangle.V0.Position.Y), z: triangle.V0.Position.Z},`
`26`		`- Point{x: math.Round(triangle.V1.Position.X), y: math.Round(triangle.V1.Position.Y), z: triangle.V1.Position.Z},`
`27`		`- Point{x: math.Round(triangle.V2.Position.X), y: math.Round(triangle.V2.Position.Y), z: triangle.V2.Position.Z},`
	`26`	`+ Point{x: (triangle.V0.Position.X), y: -(triangle.V0.Position.Z), z: -triangle.V0.Position.Y},`
	`27`	`+ Point{x: (triangle.V1.Position.X), y: -(triangle.V1.Position.Z), z: -triangle.V1.Position.Y},`
	`28`	`+ Point{x: (triangle.V2.Position.X), y: -(triangle.V2.Position.Z), z: -triangle.V2.Position.Y},`
`28`	`29`	`}`
`29`	`30`	`}`
`30`	`31`