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---
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 holds 3D modeling data for the PlayStation extended graphics library (libgs).[^ff224]

TMD data is loaded into memory and passed as an argument to libgs functions.[^ff224]

The RSDLINK utility creates TMD files. It reads an RSD file made by the SCE 3D Graphics Tool or a comparable program.[^ff224]

A TMD file holds the polygons and lines that make up a 3D object. One TMD file can hold one or more objects.[^ff224]

## Coordinate Values

TMD coordinates follow the 3D coordinate space of the 3D graphics library.[^ff224]

The positive X axis points right. The positive Y axis points down, and the positive Z axis points into the depth.[^ff224]

Each spatial coordinate is a signed 16-bit integer from -32768 to +32767.[^ff224]

RSD stores vertices as floating point values. Conversion from RSD to TMD scales the vertex values as needed.[^ff224]

The scale used is stored in the object structure. The current version of libgs ignores it.[^ff224]

## File Format

A TMD file has 4 blocks. An object table is followed by three kinds of data: PRIMITIVE, VERTEX and NORMAL.[^ff224]

### Header

The header is three words (12 bytes) of data about the structure.[^ff225]

The header fields are as follows:

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 |

FIXP sets whether the pointers in the OBJECT structures are real addresses. 1 is a real address, and 0 is an offset from the start.[^ff225]

### Obj Table

The OBJ TABLE is a table of object structures. Each one points to the data of one object.[^ff225]

The object structure is as follows:

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 |

With FIXP 1 the three pointers are real addresses. With FIXP 0 they are relative to the top of the OBJECT block.[^ff225]

The scale value is 2 raised to the scaling factor. A factor of 0 gives 1, a factor of 2 gives 4, and -1 gives 1/2.[^ff226]

The scale value returns the model to its scale at design time.[^ff226]

### Primitive

The PRIMITIVE section is a list of drawing packets. One packet is one primitive.[^ff226]

TMD primitives differ from the drawing primitives of libgpu. libgs converts a TMD primitive to a drawing primitive by perspective transformation.[^ff226]

Each packet has a variable length. Its size and structure depend on the primitive type.[^ff226]

A packet holds the following items:

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. CODE gives the entity type.[^ff226]

The CODE values are as follows:

Table: Mode CODE values

| CODE | Primitive |
| --- | --- |
| 001 | Polygon (triangle, quadrilateral) |
| 010 | Straight line |
| 011 | Sprite |

The Flag bits are as follows:[^ff226]

Table: Flag bits

| Bit | Name | Contents |
| --- | --- | --- |
| 0 | LGT | 1 no light source calculation, 0 light source calculation |
| 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 list of vertex structures.[^ff227]

Table: Vertex structure

| Word | Upper 16 bits | Lower 16 bits |
| --- | --- | --- |
| 0 | VY | VX |
| 1 | | VZ |

VX, VY and VZ are the x, y and z coordinates of the vertex as 16-bit integers.[^ff227]

### Normal

The normal section is a list of normal structures.[^ff227]

Table: Normal structure

| Word | Upper 16 bits | Lower 16 bits |
| --- | --- | --- |
| 0 | NY | NX |
| 1 | | NZ |

NX, NY and NZ are signed 16-bit fixed-point values in which 4096 is 1.0.[^ff227]

The fixed-point format is as follows:

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:[^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 |

Without light source calculation, Rn, Gn and Bn must hold the brightness to draw with.[^ff228]

### TSB

TSB holds the texture page and its modes.[^ff228]

Table: TSB fields

| Field | Contents |
| --- | --- |
| TPAGE | Texture page number (0 to 31) |
| ABR | Semi-transparency rate. Valid only when ABE is 1. |
| TPF | Color mode: 00 4-bit, 01 8-bit, 10 15-bit |

The ABR values are as follows:[^ff228]

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 of the CLUT in VRAM.[^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, a polygon Mode has the bits 0 0 1 IIP Q TME ABE TGE. Q (bit 3) is set for a 4-vertex polygon.[^ff229][^ff230]

The polygon mode bits are as follows:

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 |

The manual gives header values for 3-vertex polygons with light source calculation.[^ff230]

The values are as follows:

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 |

These values are for a single-faced polygon without semi-transparency processing.[^ff230]

A packet with light source calculation holds a normal for each vertex in Gouraud mode and one normal in flat mode.[^ff230]

A packet without light source calculation holds no normals. It holds the color to draw with.[^ff232]

### Straight Line

From the MSB, a line Mode has the bits 0 1 0 IIP 0 0 ABE 0.[^ff233]

The line mode bits are as follows:

Table: Straight line mode bits

| Bit | Name | Contents |
| --- | --- | --- |
| 1 | ABE | Translucency processing: 0 off, 1 on |
| 4 | IIP | Gradation: 0 off (monochrome), 1 on |

The manual gives the following line packet headers:[^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 has 3D coordinates. It draws the same as a normal sprite.[^ff234]

From the MSB, the 3D sprite Mode has the fields 0 1 1 SIZ 1 ABE 0.[^ff234]

The SIZ values are as follows:

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.