lowlines

J3D Model (BMD)

Category: Nintendo Gamecube

Description: Common model format used in Gamecube games.

Author: lowlines

Filename: j3d_bmd3.xml

Size: 13.45 KB

Date Modified: 22 October 2024

• Common
  • Data Attributes

    • Code					Description
      0x00					Position Matrix Index
      0x01					Tex0 Matrix Index
      0x02					Tex1 Matrix Index
      0x03					Tex2 Matrix Index
      0x04					Tex3 Matrix Index
      0x05					Tex4 Matrix Index
      0x06					Tex5 Matrix Index
      0x07					Tex6 Matrix Index
      0x08					Tex7 Matrix Index
      0x09					Position
      0x0A					Normal
      0x0B					Color0
      0x0C					Color1
      0x0D					Tex0
      0x0E					Tex1
      0x0F					Tex2
      0x10					Tex3
      0x11					Tex4
      0x12					Tex5
      0x13					Tex6
      0x14					Tex7
      0x15					Position Matrix Array
      0x16					Normal Matrix Array
      0x17					Texture Matrix Array
      0x18					Lit Matrix Array
      0x19					Normal Bi-Normal Tangent
      0x1A					Max Attr
      0xFF					Null Attr

  • Data Types

    • Code					Description
      0x00					8-bit Unsigned
      0x01					8-bit Signed
      0x02					16-bit Unsigned
      0x03					16-bit Signed
      0x04					Float

  • Texture Formats

    • Code					Description
      0x00					RGB565
      0x01					RGB888
      0x02					RGBX8
      0x03					RGBA4
      0x04					RGBA6
      0x05					RGBA8

• J3D Header

  • Type		Offset	Size	Value	Description
    Version Stamp		0x0000	4	0x4A334432	Stamp (J3D2).
    Magic Stamp		0x0004	4	0x626D6433	Stamp (bmd3).
    File Size		0x0008	4
    # Sections		0x000C	4	8
    Unused Stamp		0x0010	4	0x53565233	Stamp (SVR3).
    Unused		0x0014	12	0xFF

• Info Section (INF1)

  • Type		Offset	Size	Value	Description
    Magic Stamp		0x0000	4	0x494E4631	Stamp (INF1).
    Section Size		0x0004	4
    Unknown 1		0x0008	2
    Padding		0x000A	2	0xFFFF
    Unknown 2		0x000C	4
    # Vertices		0x0010	4
    Offset		0x0014	4

  • Hierarchy Data
    • A list of commands that make up the hierarchy tree.

    • Command					Description
      0x00					Finish
      0x01					New Node
      0x02					End Node
      0x10					Joint
      0x11					Material
      0x12					Shape

• Vertex Section (VTX1)

  • Type		Offset	Size	Value	Description
    Magic Stamp		0x0000	4	0x56545831	Stamp (VTX1).
    Section Size		0x0004	4
    Info Offset		0x0000	4		14 Offsets. If offset equals 0, no data follows.
    Data Format Info
    Format		0x0000	4
    Count		0x0004	4
    Type		0x0008	4
    Decimal Point		0x000C	1
    Padding		0x000D	3	0xFF

• Bone Weights Section (EVP1)

  • Type		Offset	Size	Value	Description
    Magic Stamp		0x0000	4	0x45565031	Stamp (EVP1).
    Section Size		0x0004	4
    Count		0x0008	2
    Padding		0x000A	2	0xFF
    Offset		0x0000	4		Repeats * Count.

• Draw Section (DRW1)

  • Type		Offset	Size	Value	Description
    Magic Stamp		0x0000	4	0x44525731	Stamp (DRW1).
    Section Size		0x0004	4
    Count		0x0008	2
    Padding		0x000A	2	0xFF
    Is Weighted Offset		0x000C	4
    Data Offset		0x0010	4
    Is Weighted Data		0x0000	2		Repeats * Count.
    Data		0x0000	2		Repeats * Count.

• Joint Section (JNT1)

  • Type		Offset	Size	Value	Description
    Magic Stamp		0x0000	4	0x4A4E5431	Stamp (JNT1).
    Section Size		0x0004	4
    Count		0x0008	2
    Padding		0x000A	2	0xFF
    Entry Offset		0x000C	4
    Unknown Offset		0x0010	4
    Names Offset		0x0014	4

  • Joint Entry Block - Repeats * Count

    • Type		Offset	Size	Value	Description
      Unknown		0x0000	2
      Padding?		0x0002	2
      Scale X		0x0004	4
      Scale Y		0x0008	4
      Scale Z		0x000C	4
      Rotate X		0x0010	2
      Rotate Y		0x0012	2
      Rotate Z		0x0014	2
      Padding		0x0016	2	0xFFFF
      Translate X		0x0018	4
      Translate Y		0x001C	4
      Translate Z		0x0020	4
      Unknown		0x0024	4
      Bounding Box X		0x0028	4
      Bounding Box Y		0x002C	4
      Bounding Box Z		0x0030	4
      Bounding Box X2		0x0034	4
      Bounding Box Y2		0x0038	4
      Bounding Box Z2		0x003C	4

  • Unknown Block - Repeats * Count
    • No notes...
  • Names Block - Repeats * Count
    • No notes...
• Shape Section (SHP1)

  • Type		Offset	Size	Value	Description
    Magic Stamp		0x0000	4	0x53485031	Stamp (SHP1).
    Section Size		0x0004	4
    # Shapes		0x0008	2
    Padding		0x000A	2	0xFF
    Batch Offset		0x000C	4
    Unknown Offset		0x0010	4
    Padding?		0x0014	4	0x00000000
    Attributes Offset		0x0018	4
    Matrix Table Offset		0x001C	4
    Data Offset		0x0020	4
    Matrix Data Offset		0x0024	4
    Packet Offset		0x0028	4

  • Batch Block - Repeats * Number of Shapes

    • Type		Offset	Size	Value	Description
      Unknown		0x0000	1
      Padding		0x0001	1	0xFF
      # Packets		0x0002	2
      Attribute Offset		0x0004	2
      First Matrix Index		0x0006	2
      First Packet Index		0x0008	2
      Padding		0x000A	2	0xFFFF
      Unknown 1		0x000C	4
      Unknown 2		0x0010	4
      Unknown 3		0x0014	4
      Unknown 4		0x0018	4
      Unknown 5		0x001C	4
      Unknown 6		0x0020	4
      Unknown 7		0x0024	4

  • Unknown Block - Repeats * Number of Shapes

    • Type		Offset	Size	Value	Description
      Unknown		0x0000	2

  • Attributes Block

    • Type		Offset	Size	Value	Description
      Attribute		0x0000	4
      Type		0x0004	4

  • Matrix Table Offsets Block - Repeats * Number of Shapes

    • Type		Offset	Size	Value	Description
      Offset		0x0000	2

  • Data Block

    • Type		Offset	Size	Value	Description
      Primitive Type		0x0000	1
      # Vertices		0x0001	2
      Data		0x0003			Repeats * Number of Vertices. Holds indexes to data stored in the VTX1 section for each attribute.

    • Primitive Types

      • Code					Description
        0x80?					QUADS
        0x80?					TRIANGLES
        0x98					TRIANGLESTRIP
        0xA0					TRIANGLEFAN
        0xA8					LINES
        0xB0					LINSTRIP
        0xB8					POINTS

  • Matrix Table Block

    • Type		Offset	Size	Value	Description
      Unknown		0x0000	2
      Count		0x0002	2
      First Index		0x0004	4

  • Packet Location Block - Repeats * Number of Shapes

    • Type		Offset	Size	Value	Description
      Size		0x0000	4
      Offset		0x0004	4		Relative to Data Offset.

• Materials Section (MAT3)
  • No notes...
• Textures Section (TEX1)

  • Type		Offset	Size	Value	Description
    Magic Stamp		0x0000	4	0x53485031	Stamp (TEX1).
    Section Size		0x0004	4
    # Textures		0x0008	2
    Padding		0x000A	2	0xFF
    Data Offset		0x000C	4
    Names Offset		0x0010	4