psx.wiki
Log in
Main page
Hardware
Hardware tests
System software
SDKs
File formats
Games
Tools
History
All pages
page
view source
history
View source for TMD (Modeling Data for OS Library)
← TMD (Modeling Data for OS Library)
You do not have permission to edit this page.
Log in
to edit.
--- title: TMD (Modeling Data for OS Library) type: format summary: 3D modeling data for the extended graphics library (libgs). category: File formats info: Extension = .TMD info: ID = 0x00000041 info: Created by = RSDLINK --- ## Overview The TMD format contains 3D modeling data that is compatible with the PlayStation extended graphics library (libgs). TMD data is loaded into memory and passed as an argument to the functions of libgs. TMD files are created by the RSDLINK utility, which reads an [RSD](/formats/rsd/) file made by the SCE 3D Graphics Tool or a comparable program.[^ff224] The data in a TMD file is a set of graphics primitives, such as polygons and lines, that make up a 3D object. A single TMD file can contain one or more 3D objects.[^ff224] ## Coordinate Values Coordinate values in a TMD file follow the 3D coordinate space of the 3D graphics library. The positive X axis points right, the positive Y axis points down and the positive Z axis points into the depth. Each spatial coordinate is a signed 16-bit integer from -32768 to +32767.[^ff224] At design time and in the RSD format, vertices are stored as floating point values. Conversion from RSD to TMD therefore converts and scales the vertex values as needed, and the scale used is recorded in the object structure. This value can serve as an index for mapping from object to world coordinates. However, the current version of libgs ignores it.[^ff224] ## File Format A TMD file has 4 blocks. A table of 3D objects is followed by the three kinds of data that make up the objects: PRIMITIVE, VERTEX and NORMAL.[^ff224] ### Header The header is three words (12 bytes) of data about the structure of the file:[^ff225] Table: TMD header | Field | Contents | | --- | --- | | ID | Version of the TMD file, 32 bits. The current version is 0x00000041. | | FLAGS | 32 bits. Bit 0 is FIXP. The other bits are reserved and zero. | | NOBJ | Number of objects | The FIXP bit shows whether the pointers in the OBJECT structures are real addresses. A value of 1 means a real address, and a value of 0 means an offset from the start.[^ff225] ### Obj Table The OBJ TABLE is a table of structures, each of which points to the place where the data of one object is stored. The object structure has the following configuration:[^ff225] Table: Object structure | Member | Type | Contents | | --- | --- | --- | | vert_top | u_long * | Start address of the vertices | | n_vert | u_long | Number of vertices | | normal_top | u_long * | Start address of the normals | | n_normal | u_long | Number of normals | | primitive_top | u_long * | Start address of the primitives | | n_primitive | u_long | Number of primitives | | scale | long | Scaling factor | The meaning of the three pointers depends on the FIXP bit in the header. If FIXP is 1 they are actual addresses, and if FIXP is 0 they are relative addresses that take the top of the OBJECT block as address 0.[^ff225] The scaling factor is a signed long, and the scale value is 2 raised to its power. A factor of 0 therefore gives a scale of 1, a factor of 2 gives 4 and a factor of -1 gives 1/2. With this value the model can be returned to its scale at design time.[^ff226] ### Primitive The PRIMITIVE section is an arrangement of drawing packets in which one packet stands for one primitive of the object. TMD primitives differ from the drawing primitives handled by libgpu. A TMD primitive is converted to a drawing primitive by the perspective transformation that libgs performs.[^ff226] Each packet has a variable length, and its size and structure depend on the primitive type. A packet holds the following items:[^ff226][^ff227] Table: Drawing packet items | Item | Size | Contents | | --- | --- | --- | | Mode | 8 bits | Type of primitive and its attributes | | Flag | 8 bits | Options for rendering | | Ilen | 8 bits | Length of the packet data section in words | | Olen | 8 bits | Word length of the 2D drawing primitive made by intermediate processing | | Packet data | Ilen words | Vertex and normal parameters | The top 3 bits of Mode are CODE, which gives the kind of entity. The other bits of Mode depend on CODE and are listed with the packet configurations below.[^ff226] Table: Mode CODE values | CODE | Primitive | | --- | --- | | 001 | Polygon (triangle, quadrilateral) | | 010 | Straight line | | 011 | Sprite | Flag carries option information for rendering:[^ff226][^ff227] Table: Flag bits | Bit | Name | Contents | | --- | --- | --- | | 0 | LGT | 1 light source calculation not carried out, 0 light source calculation carried out | | 1 | FCE | 1 double-faced polygon, 0 single-faced polygon. Valid only for polygons. | | 2 | GRD | 1 gradation polygon, 0 single-color polygon. Valid only for an untextured polygon with light source calculation. | | 3..7 | | 0 | ### Vertex The vertex section is a set of vertex structures. In each structure VX, VY and VZ are the x, y and z coordinates of the vertex as 16-bit integers:[^ff227] Table: Vertex structure | Word | Upper 16 bits | Lower 16 bits | | --- | --- | --- | | 0 | VY | VX | | 1 | | VZ | ### Normal The normal section is a set of normal structures with the same layout. NX, NY and NZ are signed 16-bit fixed-point values in which 4096 is 1.0, so a normal component has 1 sign bit, 3 integer bits and 12 fraction bits.[^ff227] Table: Normal structure | Word | Upper 16 bits | Lower 16 bits | | --- | --- | --- | | 0 | NY | NX | | 1 | | NZ | Table: Fixed-point format | Bits | Part | | --- | --- | | 15 | Sign (1 bit) | | 12..14 | Integral part (3 bits) | | 0..11 | Decimal part (12 bits) | ## Packet Data The packet data section holds the following parameters. Without light source calculation the predetermined brightness must be entered in Rn, Gn and Bn.[^ff228] Table: Packet data parameters | Parameter | Contents | | --- | --- | | Vertex(n) | 16-bit index of a vertex, counted from the start of the object's vertex section | | Normal(n) | 16-bit index of a normal, counted in the same way | | Un, Vn | X and Y coordinates of each vertex in the texture source space | | Rn, Gn, Bn | Polygon color as unsigned 8-bit integers | | TSB | Texture page and sprite pattern information | | CBA | Position of the CLUT in VRAM | ### TSB TSB carries the texture page number and the modes used with it. ABR is valid only when ABE is 1.[^ff228] Table: TSB fields | Field | Contents | | --- | --- | | TPAGE | Texture page number (0 to 31) | | ABR | Semi-transparency rate (mixture rate) | | TPF | Color mode: 00 4-bit, 01 8-bit, 10 15-bit | Table: ABR semi-transparency rates | ABR | Mixture | | --- | --- | | 00 | 50% back + 50% polygon | | 01 | 100% back + 100% polygon | | 10 | 100% back - 100% polygon | | 11 | 100% back + 25% polygon | ### CBA CBA gives the position where the CLUT is stored in VRAM. CLX holds only the upper 6 bits of the 10-bit X coordinate, so a CLUT starts on a multiple of 16 pixels in X.[^ff228] Table: CBA fields | Bits | Field | Contents | | --- | --- | --- | | 0..5 | CLX | Upper 6 bits of the 10-bit X coordinate of the CLUT | | 6..14 | CLY | 9-bit Y coordinate of the CLUT | ## Primitive Types ### Polygons From the MSB, the Mode of a polygon has the bits 0 0 1 IIP Q TME ABE TGE, where bit 3 (Q) is set for a 4-vertex polygon. The other bits select shading, texture and translucency as follows:[^ff229][^ff230] Table: Polygon mode bits | Bit | Name | Contents | | --- | --- | --- | | 0 | TGE | Brightness calculation at texture mapping: 0 on, 1 off (draws the texture as is) | | 1 | ABE | Translucency processing: 0 off, 1 on | | 2 | TME | Texture: 0 off, 1 on | | 3 | | 1 for a 4-vertex primitive | | 4 | IIP | Shading mode: 0 flat, 1 Gouraud | | 5..7 | CODE | 001 | A packet with light source calculation holds one normal in flat mode and a normal for each vertex in Gouraud mode. The manual gives the following header values for a single-faced 3-vertex polygon without semi-transparency processing:[^ff230] Table: 3-vertex polygon packets with light source calculation | Packet | Mode | Flag | Ilen | Olen | | --- | --- | --- | --- | --- | | Flat, no texture (solid) | 0x20 | 0x00 | 0x03 | 0x04 | | Gouraud, no texture (solid) | 0x30 | 0x00 | 0x04 | 0x06 | | Flat, no texture (gradation) | 0x20 | 0x04 | 0x05 | 0x06 | | Gouraud, no texture (gradation) | 0x30 | 0x04 | 0x06 | 0x06 | | Flat, texture | 0x24 | 0x00 | 0x05 | 0x07 | | Gouraud, texture | 0x34 | 0x00 | 0x06 | 0x09 | A packet without light source calculation holds no normals. In this case it holds the color to draw with instead.[^ff232] ### Straight Line From the MSB, the Mode of a straight line has the bits 0 1 0 IIP 0 0 ABE 0. IIP turns gradation on and ABE turns translucency processing on. The manual gives the following line packet headers:[^ff233][^ff234] Table: Straight line packets | Packet | Mode | Flag | Ilen | Olen | | --- | --- | --- | --- | --- | | Gradation off | 0x40 | 0x01 | 0x02 | 0x03 | | Gradation on | 0x50 | 0x01 | 0x03 | 0x04 | ### 3D Sprite A 3D sprite is a sprite with 3D coordinates, and its drawing content is the same as a normal sprite. From the MSB its Mode has the fields 0 1 1 SIZ 1 ABE 0, where SIZ sets the sprite size:[^ff234] Table: 3D sprite SIZ values | SIZ | Sprite size | | --- | --- | | 00 | Free size (specified by W, H) | | 01 | 1 x 1 | | 10 | 8 x 8 | | 11 | 16 x 16 | ## References [^ff224]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-24. [^ff225]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-25, Figures 55 and 56. [^ff226]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-26, Figures 58 and 59. [^ff227]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-27, Figures 60 to 62. [^ff228]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-28, Figures 63 and 64. [^ff229]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-29, Figure 65. [^ff230]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-30, Figures 66 and 67. [^ff232]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-32, Figure 70. [^ff233]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-33, Figure 73. [^ff234]: Sony Computer Entertainment Inc. File Formats. November 1998. Page 2-34, Figures 74 and 75.