Autodesk 3D Studio

Also Known As: 3DS, ASC

Type	Scene
Colors	Unlimited
Compression	None
Maximum Image Size	None
Multiple Images Per File	NA
Numerical Format	Multiple
Originator	Autodesk
Platform	MS-DOS
Supporting Applications	3D Studio, Caligari trueSpace, other 3D programs
See Also	None

Usage
Storage of 3D scene information for use by rendering applications.

Comments
Autodesk 3D Studio has come to be used as an interchange format. Many 3D modeling and rendering applications read and write 3DS, as well as their own formats. Why this is so is not clear but may be due to Autodesk 3D Studio's longevity and visibility in the market. The program implements a large number of functions, however, and this is reflected in the file.

Autodesk 3D Studio (3DS) is a relatively high-end program used for the modeling and rendering of 3D scenes. It runs under MS-DOS and uses a third-party memory manager to make optimum use of the resources available on the PC platform. Output compares favorably to many higher end platforms. It has thus become one of the platforms of choice for people doing detailed construction of 3D scenes.

Contents:
File Organization
File Details
For Further Information

Unfortunately, Autodesk has chosen to make information about this format available only through purchase of their developer's kit. Information for this article was accordingly obtained from public sources and is necessarily incomplete. We would appreciate any further information available on this format.

There are two formats used by 3D Studio:

• A binary one designated by the suffix 3DS

• An ASCII format using the suffix ASC

Both are used as interchange formats. This article concentrates on the binary version of the file, because the ASCII version is usually used for the storage of object definitions and closely follows the tags defined in the binary version. At the end of this article, we provide an example of a simple ASC file.

File Organization

3DS files consist of tags, called chunks by Autodesk. Each chunk consists of an ID value and an offset to the start of the next chunk. Data associated with each chunk follows the ID and offset information.

typedef struct _CHUNK
{
   WORD  Chunk_ID;       /* Tag type */
   DWORD Chunk_length;   /* Relative offset in bytes to next chunk */
} CHUNK;

Chunks are classified as either Primary, Main, or Subordinate and are arranged in a hierarchy as follows:

Primary Chunk
   Main Chunk #1
      Subordinate Chunk #1
      Subordinate Chunk #2
       
.
.
.

   Main Chunk #2
      Subordinate Chunk #1
      Subordinate Chunk #2
       
.
.
.

   Main Chunk #3
    
.
.
.

The Main chunks are said to be "owned" by the Primary chunk, and the Subordinate chunks associated with the Main chunks are owned by the Main chunk. Note that many of the chunks defined below are associated with the behavior of 3D Studio at run-time. They are listed here because your rendering application or file conversion program may be able to make use of them as clues to the appearance and behavior of the objects found in the file.

There is only one Primary chunk per file, located at the start of the file. Following the Primary chunk tag is the first Main tag. The chunk_length field of Main chunk tags is generally an offset to the next Main chunk.

Following each Main chunk tag is data associated with the Main chunk and/or Subordinate chunk tags. Thus, the reader/parser must understand the format and length of the data associated with each Main chunk in order to extract information contained in Subordinate chunks owned by the Main chunk.

File Details

The first tag of the file, the Primary chunk, has an ID of 4D4Dh. Beneath the Primary chunk in the tag hierarchy are Main chunks.

Chunks

Table Autodesk 3D Studio-1 lists the possible chunks known at this time:

Table Autodesk 3D Studio-1: Autodesk 3D Studio Chunks

ID	Name	Data Type	Description
0000	NULL_CHUNK	NA
0001	unknown	(possibly FLOAT)
0002	M3D_VERSION	SHORT	Version
0005	M3D_KFVERSION	NA
0010	COLOR_F	FLOAT R,G,B	Floating-point color description
0011	COLOR_24	BYTE R,G,B	24-bit color description
0012	LIN_COLOR_24	BYTE R,G,B	24-bit color description
0013	LIN_COLOR_F	FLOAT R,G,B	Floating-point color description
0030	INT_PERCENTAGE	SHORT	Percentage value
0031	FLOAT_PERCENTAGE	FLOAT	Percentage value
0100	MASTER_SCALE	FLOAT	Scale factor
0995	ChunkType	NA
0996	ChunkUnique	NA
0997	NotChunk	NA
0998	Container	NA
0999	IsChunk	NA
0c3c	C_SXP_SELFI_MASKDATA	NA
1100	BIT_MAP	CHAR[]	0-terminated ASCII string
1101	USE_BIT_MAP	NA
1200	SOLID_BGND	FLOAT R,G,B
1201	USE_SOLID_BGND	NA
1300	V_GRADIENT	FLOAT	Midpoint of gradient
1301	USE_V_GRADIENT	NA
1400	LO_SHADOW_BIAS	FLOAT	Bias
1410	HI_SHADOW_BIAS	NA
1420	SHADOW_MAP_SIZE	SHORT	Size
1430	SHADOW_SAMPLES	NA
1430	SHADOW_RANGE	NA
1430	SHADOW_FILTER	FLOAT	Filter
1460	RAY_BIAS	FLOAT	Bias
1500	O_CONSTS	FLOAT x,y,z	Plane values
2100	AMBIENT_LIGHT	NA
2200	FOG	FLOAT[4]	near_plane, near_density, far_plane, far_density
2201	USE_FOG	NA
2210	FOG_BGND	NA
2300	DISTANCE_CUE	FLOAT[4]	near_plane, near_density, far_plane, far_density
2301	USE_DISTANCE_CUE	NA
2302	LAYER_FOG	FLOAT[3],	fog_z_from, fog_z_to, fog_density
		SHORT	fog_type
2303	USE_LAYER_FOG	NA
2310	DCUE_BGND	NA
2d2d	SMAGIC	NA
2d3d	LMAGIC	NA
3000	DEFAULT_VIEW	NA
3010	VIEW_TOP	FLOAT[4]	target_x, target_y, target_z, view_width
3020	VIEW_BOTTOM	FLOAT[4]	target_x, target_y, target_z, view_width
3030	VIEW_LEFT	FLOAT[4]	target_x, target_y, target_z, view_width
3040	VIEW_RIGHT	FLOAT[4]	target_x, target_y, target_z, view_width
3050	VIEW_FRONT	FLOAT[4]	target_x, target_y, target_z, view_width
3060	VIEW_BACK	FLOAT[4]	target_x, target_y, target_z, view_width
3070	VIEW_USER	FLOAT[4]	target_x, target_y, target_z, view_width
3080	VIEW_CAMERA	CHAR[]	0-terminated ASCII string
3090	VIEW_WINDOW	NA
3d3d	MDATA	WORD	Mesh data magic number 4d4d
3d3e	MESH_VERSION	NA
3daa	MLIBMAGIC	WORD	Material library magic number
3dc2	PRJMAGIC	WORD	Project number magic number
3dff	MATMAGIC	WORD	Material file magic number
4000	NAMED_OBJECT	CHAR[]	0-terminated ASCII string
4010	OBJ_HIDDEN	NA
4011	OBJ_VIS_LOFTER	NA
4012	OBJ_DOESNT_CAST	NA
4013	OBJ_MATTE	NA
4014	OBJ_FAST	NA
4015	OBJ_PROCEDURAL	NA
4016	OBJ_FROZEN	NA
4017	OBJ_DONT_RCVSHADOW	NA
4100	N_TRI_OBJECT	NA	Named triangle object
4110	POINT_ARRAY	SHORT,	Number of points
		POINT[]	Array of POINT structs
4111	POINT_FLAG_ARRAY	SHORT,	Number of flags
		SHORT[]	Array of SHORT flags
4120	FACE_ARRAY	SHORT,	Number of faces
		FACE[]	Array of FACE structs
4130	MSH_MAT_GROUP	CHAR[],	Material name
		SHORT,	Number of faces
		SHORT[]	Face numbers
4140	TEX_VERTS	SHORT,	Number of vertices
		VERTEX[]	Array of VERTEX structs
4150	SMOOTH_GROUP	SHORT[]	Groups = faces x 4
4160	MESH_MATRIX	FLOAT[4][3]	4x3 FLOAT matrix
4170	MESH_TEXTURE_INFO	SHORT,	map_type
		FLOAT[2],	x_tiling, y_tiling
		FLOAT[3],	icon_x, icon_y, icon_z
		FLOAT[4][3],	4x3 FLOAT matrix
		FLOAT[4]	scaling, plan_icon_w, plan_icon_h, cyl_icon_h
4181	PROC_NAME	NA
4182	PROC_DATA	NA
4190	MSH_BOXMAP	NA
4400	N_D_L_OLD	NA
4500	N_CAM_OLD	NA
4600	N_DIRECT_LIGHT	FLOAT[3]	x,y,z of light
4610	DL_SPOTLIGHT	FLOAT[5]	target_x, target_y, target_z, hotspot_ang, falloff_ang
4620	DL_OFF	NA
4625	DL_ATTENUATE	NA
4627	DL_RAYSHAD	NA
4630	DL_SHADOWED	NA
4640	DL_LOCAL_SHADOW	NA
4641	DL_LOCAL_SHADOW2	NA
4650	DL_SEE_CONE	NA
4651	DL_SPOT_RECTANGULAR	NA
4652	DL_SPOT_OVERSHOOT	NA
4653	DL_SPOT_PROJECTOR	NA
4654	DL_EXCLUDE	NA
4655	DL_RANGE	NA
4656	DL_SPOT_ROLL	FLOAT	Roll angle
4657	DL_SPOT_ASPECT	NA
4658	DL_RAY_BIAS	FLOAT	Bias
4659	DL_INNER_RANGE	FLOAT	Range
465a	DL_OUTER_RANGE	FLOAT	Range
465b	DL_MULTIPLIER	FLOAT	Multiplier value
4680	N_AMBIENT_LIGHT	NA
4700	N_CAMERA	FLOAT[3],	camera_x, camera_y, camera_z
		FLOAT[3],	target_x, target_y, target_z
		FLOAT[2]	bank_angle, focus
4710	CAM_SEE_CONE	NA
4720	CAM_RANGES	FLOAT[2]	near_range, far_range
4d4d	M3DMAGIC	NA	3DS file magic number
4f00	HIERARCHY	NA
4f10	PARENT_OBJECT	NA
4f20	PIVOT_OBJECT	NA
4f30	PIVOT_LIMITS	NA
4f40	PIVOT_ORDER	NA
4f50	XLATE_RANGE	NA
5000	POLY_2D	NA
5010	SHAPE_OK	NA
5011	SHAPE_NOT_OK	NA
5020	SHAPE_HOOK	NA
6000	PATH_3D	NA
6005	PATH_MATRIX	NA
6010	SHAPE_2D	NA
6020	M_SCALE	NA
6030	M_TWIST	NA
6040	M_TEETER	NA
6050	M_FIT	NA
6060	M_BEVEL	NA
6070	XZ_CURVE	NA
6080	YZ_CURVE	NA
6090	INTERPCT	NA
60a0	DEFORM_LIMIT	NA
6100	USE_CONTOUR	NA
6110	USE_TWEEN	NA
6120	USE_SCALE	NA
6130	USE_TWIST	NA
6140	USE_TEETER	NA
6150	USE_FIT	NA
6160	USE_BEVEL	NA
7000	VIEWPORT_LAYOUT_OLD	NA
7001	VIEWPORT_LAYOUT	SHORT[7]	form, top, ready, wstate, swapws, swapport, swapcur
7010	VIEWPORT_DATA_OLD	NA
7011	VIEWPORT_DATA	SHORT[7],	flags, axis_lockout, win_x, win_y, win_w, win_h, win_view
		FLOAT[6],	zoom, worldcenter_x, worldcenter_y, worldcenter_z, horiz_and, vert_ang
		CHAR[]	0-terminated ASCII string--camera name
7011	VIEWPORT_DATA_3	SHORT[7],	flags, axis_lockout, win_x, win_y, win_w, win_h, win_view
		FLOAT[6],	zoom, worldcenter_x, worldcenter_y, worldcenter_z, horiz_and, vert_ang
		CHAR[]	0-terminated ASCII string--camera name
7020	VIEWPORT_SIZE	SHORT[4]	x,y,width,height
7030	NETWORK_VIEW	NA
8000	XDATA_SECTION	NA
8001	XDATA_ENTRY	NA
8002	XDATA_APPNAME	NA
8003	XDATA_STRING	NA
8004	XDATA_FLOAT	NA
8005	XDATA_DOUBLE	NA
8006	XDATA_SHORT	NA
8007	XDATA_LONG	NA
8008	XDATA_VOID	NA
8009	XDATA_GROUP	NA
800a	XDATA_RFU6	NA
800b	XDATA_RFU5	NA
800c	XDATA_RFU4	NA
800d	XDATA_RFU3	NA
800e	XDATA_RFU2	NA
800f	XDATA_RFU1	NA
80f0	PARENT_NAME	NA
a000	MAT_NAME	CHAR[]	0-terminated ASCII string--material name
a010	MAT_AMBIENT	NA
a020	MAT_DIFFUSE	NA
a030	MAT_SPECULAR	NA
a040	MAT_SHININESS	NA
a041	MAT_SHIN2PCT	NA
a042	MAT_SHIN3PCT	NA
a050	MAT_TRANSPARENCY	NA
a052	MAT_XPFALL	NA
a053	MAT_REFBLUR	NA
a080	MAT_SELF_ILLUM	NA
a081	MAT_TWO_SIDE	NA
a082	MAT_DECAL	NA
a083	MAT_ADDITIVE	NA
a084	MAT_SELF_ILPCT	NA
a085	MAT_WIRE	NA
a086	MAT_SUPERSMP	NA
a087	MAT_WIRESIZE	FLOAT	Wire size
a088	MAT_FACEMAP	NA
a08a	MAT_XPFALLIN	NA
a08c	MAT_PHONGSOFT	NA
a08e	MAT_WIREABS	NA
a100	MAT_SHADING	SHORT	Shading value
a200	MAT_TEXMAP	NA
a204	MAT_SPECMAP	NA
a210	MAT_OPACMAP	NA
a220	MAT_REFLMAP	NA
a230	MAT_BUMPMAP	NA
a240	MAT_USE_XPFALL	NA
a250	MAT_USE_REFBLUR	NA
a252	MAT_BUMP_PERCENT	NA
a300	MAT_MAPNAME	CHAR[]	0-terminated ASCII filename
a310	MAT_ACUBIC	NA
a320	MAT_SXP_TEXT_DATA	NA
a321	MAT_SXP_TEXT2_DATA	NA
a322	MAT_SXP_OPAC_DATA	NA
a324	MAT_SXP_BUMP_DATA	NA
a325	MAT_SXP_SPEC_DATA	NA
a326	MAT_SXP_SHIN_DATA	NA
a328	MAT_SXP_SELF1_DATA	NA
a32a	MAT_SXP_TEXT_DATA	NA
a32c	MAT_SXP_TEXT2_MASKDATA	NA
a32e	MAT_SXP_OPAC_MASKDATA	NA
a330	MAT_SXP_BUMP_MASKDATA	NA
a332	MAT_SXP_SPEC_MASKDATA	NA
a334	MAT_SXP_SHIN_MASKDATA	NA
a336	MAT_SXP_SELF1_MASKDATA	NA
a338	MAT_SXP_REFL_MASKDATA	NA
a33a	MAT_TEX2MAP	NA
a33c	MAT_SHINMAP	NA
a33d	MAT_SELFIMAP	NA
a33e	MAT_TEXMASK	NA
a340	MAT_TEX2MASK	NA
a342	MAT_OPACMASK	NA
a344	MAT_BUMPMASK	NA
a346	MAT_SHINMASK	NA
a348	MAT_SPECMASK	NA
a34a	MAT_SELFIMASK	NA
a34c	MAT_REFLMASK	NA
a350	MAT_MAP_TILINGOLD	NA
a351	MAT_MAP_TILING	SHORT	Flags
a352	MAT_MAP_TEXBLUR_OLD	NA
a353	MAT_MAP_TEXBLUR	FLOAT	Blurring value
a354	MAT_MAP_USCALE	NA
a356	MAT_MAP_VSCALE	NA
a358	MAT_MAP_UOFFSET	NA
a35a	MAT_MAP_VOFFSET	NA
a35c	MAT_MAP_ANG	NA
a360	MAT_MAP_COL1	NA
a362	MAT_MAP_COL2	NA
a364	MAT_MAP_RCOL	NA
a366	MAT_MAP_GCOL	NA
a368	MAT_MAP_BCOL	NA
afff	MAP_ENTRY	NA
b000	KFDATA	NA
b001	AMBIENT_NODE_TAG	NA
b002	OBJECT_NODE_TAG	NA
b003	CAMERA_NODE_TAG	NA
b004	TARGET_NODE_TAG	NA
b005	LIGHT_NODE_TAG	NA
b006	L_TARGET_NODE_TAG	NA
b007	SPOTLIGHT_NODE_TAG	NA
b008	KFSEG	SHORT[2]	start, end
b009	KFCURTIME	SHORT	curframe
b00a	KFHDR	SHORT,	Revision number
		CHAR[],	0-terminated ASCII filename
		SHORT	Animation length
b010	NODE_HDR	CHAR[],	0-terminated ASCII object name
		SHORT[3]	flags1, flags2, hierarchy
b011	INSTANCE_NAME	NA
b012	PRESCALE	NA
b013	PIVOT	FLOAT[3]	pivot_x, pivot_y, pivot_z
b014	BOUNDBOX	NA
b015	MORPH_SMOOTH	FLOAT	Smoothing angle (radians)
b020	POS_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT	Unknown
		POSITION[keys]	Array of POSITION structs
b021	ROT_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		ROTATION[keys]	Array of ROTATION structs
b022	SCL_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		SCALE[keys]	Array of SCALE structs
b023	FOV_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		FOV[keys]	Array of FOV structs
b024	ROLL_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		ROLL[keys]	Array of ROLL structs
b025	COL_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		COLOR[keys]	Array of COLOR structs
b026	MORPH_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		MORPH[keys]	Array of MORPH structs
b027	HOT_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		HOTSPOT[keys]	Array of HOTSPOT structs
b028	FALL_TRACK_TAG	SHORT,	Flags
		SHORT[4],	Unknown
		SHORT,	Keys
		SHORT,	Unknown
		FALLOFF[keys]	Array of FALLOFF structs
b029	HIDE_TRACK_TAG	NA
b030	NODE_ID	SHORT	ID value
c010	C_MDRAWER	NA
c020	C_TDRAWER	NA
c030	C_SHPDRAWER	NA
c040	C_MODDRAWER	NA
c050	C_RIPDRAWER	NA
c060	C_TXDDRAWER	NA
c062	C_PDRAWER	NA
c064	C_MTLDRAWER	NA
c066	C_FLIDRAWER	NA
c067	C_CUBDRAWER	NA
c070	C_MFILE	NA
c080	C_SHPFILE	NA
c090	C_MODFILE	NA
c0a0	C_RIPFILE	NA
c0b0	C_TXFILE	NA
c0b2	C_PFILE	NA
c0b4	C_MTLFILE	NA
c0b6	C_FLIFILE	NA
c0b8	C_PALFILE	NA
c0c0	C_TX_STRING	NA
c0d0	C_CONSTS	NA
c0e0	C_SNAPS	NA
c0f0	C_GRIDS	NA
c100	C_ASNAPS	NA
c110	C_GRID_RANGE	NA
c120	C_RENDTYPE	NA
c130	C_PROGMODE	NA
c140	C_PREVMODE	NA
c150	C_MODWMODE	NA
c160	C_MODMODEL	NA
c170	C_ALL_LINES	NA
c180	C_BACK_TYPE	NA
c190	C_MD_CS	NA
c1a0	C_MD_CE	NA
c1b0	C_MD_SML	NA
c1c0	C_MD_SMW	NA
c1c3	C_LOFT_WITH_TEXTURE	NA
c1c4	C_LOFT_L_REPEAT	NA
c1c5	C_LOFT_W_REPEAT	NA
c1c6	C_LOFT_UV_NORMALIZE	NA
c1c7	C_WELD_LOFT	NA
c1d0	C_MD_PDET	NA
c1e0	C_MD_SDET	NA
c1f0	C_RGB_MODE	NA
c200	C_RGB_HIDE	NA
c202	C_RGB_MAPSW	NA
c204	C_RGB_TWOSIDE	NA
c208	C_RGB_SHADOW	NA
c210	C_RGB_AA	NA
c220	C_RGB_OVW	NA
c230	C_RGB_OVH	NA
c23d	CMAGIC	NA
c240	C_RGB_PICTYPE	NA
c250	C_RGB_OUTPUT	NA
c253	C_RGB_TODISK	NA
c254	C_RGB_COMPRESS	NA
c255	C_JPEG_COMPRESSION	NA
c256	C_RGB_DISPDEV	NA
c259	C_RGB_HARDDEV	NA
c25a	C_RGB_PATH	NA
c25b	C_BITMAP_DRAWER	NA
c260	C_RGB_FILE	NA
c270	C_RGB_OVASPECT	NA
c271	C_RGB_ANIMTYPE	NA
c272	C_RENDER_ALL	NA
c273	C_REND_FROM	NA
c274	C_REND_TO	NA
c275	C_REND_NTH	NA
c276	C_PAL_TYPE	NA
c277	C_RND_TURBO	NA
c278	C_RND_MIP	NA
c279	C_BGND_METHOD	NA
c27a	C_AUTO_REFLECT	NA
c27b	C_VP_FROM	NA
c27c	C_VP_TO	NA
c27d	C_VP_NTH	NA
c27e	C_REND_TSTEP	NA
c27f	C_VP_TSTEP	NA
c280	C_SRDIAM	NA
c290	C_SRDEG	NA
c2a0	C_SRSEG	NA
c2b0	C_SRDIR	NA
c2c0	C_HETOP	NA
c2d0	C_HEBOT	NA
c2e0	C_HEHT	NA
c2f0	C_HETURNS	NA
c300	C_HEDEG	NA
c310	C_HESEG	NA
c320	C_HEDIR	NA
c330	C_QUIKSTUFF	NA
c340	C_SEE_LIGHTS	NA
c350	C_SEE_CAMERAS	NA
c360	C_SEE_3D	NA
c370	C_MESHSEL	NA
c380	C_MESHUNSEL	NA
c390	C_POLYSEL	NA
c3a0	C_POLYUNSEL	NA
c3a2	C_SHPLOCAL	NA
c3a4	C_MSHLOCAL	NA
c3b0	C_NUM_FORMAT	NA
c3c0	C_ARCH_DENOM	NA
c3d0	C_IN_DEVICE	NA
c3e0	C_MSCALE	NA
c3f0	C_COMM_PORT	NA
c400	C_TAB_BASES	NA
c410	C_TAB_DIVS	NA
c420	C_MASTER_SCALES	NA
c430	C_SHOW_1STVERT	NA
c440	C_SHAPER_OK	NA
c450	C_LOFTER_OK	NA
c460	C_EDITOR_OK	NA
c470	C_KEYFRAMER_OK	NA
c480	C_PICKSIZE	NA
c490	C_MAPTYPE	NA
c4a0	C_MAP_DISPLAY	NA
c4b0	C_TILE_XY	NA
c4c0	C_MAP_XYZ	NA
c4d0	C_MAP_SCALE	NA
c4e0	C_MAP_MATRIX_OLD	NA
c4e1	C_MAP_MATRIX	NA
c4f0	C_MAP_WID_HT	NA
c500	C_OBNAME	NA
c510	C_CAMNAME	NA
c520	C_LTNAME	NA
c525	C_CUR_MNAME	NA
c526	C_CURMTL_FROM_MESH	NA
c527	C_GET_SHAPE_MAKE_FACES	NA
c530	C_DETAIL	NA
c540	C_VERTMARK	NA
c550	C_MSHAX	NA
c560	C_MSHCP	NA
c570	C_USERAX	NA
c580	C_SHOOK	NA
c590	C_RAX	NA
c5a0	C_STAPE	NA
c5b0	C_LTAPE	NA
c5c0	C_ETAPE	NA
c5c8	C_KTAPE	NA
c5c0	C_ETAPE	NA
c5d0	C_SPHSEGS	NA
c5e0	C_GEOSMOOTH	NA
c5f0	C_HEMISEGS	NA
c600	C_PRISMSEGS	NA
c610	C_PRISMSIDES	NA
c620	C_TUBESEGS	NA
c630	C_TUBESIDES	NA
c640	C_TORSEGS	NA
c650	C_TORSIDES	NA
c660	C_CONESIDES	NA
c661	C_CONESEGS	NA
c670	C_NGPARMS	NA
c680	C_PTHLEVEL	NA
c690	C_MSCSYM	NA
c6a0	C_MFTSYM	NA
c6b0	C_MTTSYM	NA
c6c0	C_SMOOTHING	NA
c6d0	C_MODICOUNT	NA
c6e0	C_FONTSEL	NA
c6f0	C_TESS_TYPE	NA
c6f1	C_TESS_TENSION	NA
c700	C_SEG_START	NA
c705	C_SEG_END	NA
c710	C_CURTIME	NA
c715	C_ANIMLENGTH	NA
c720	C_PV_FROM	NA
c725	C_PV_TO	NA
c730	C_PV_DOFNUM	NA
c735	C_PV_RNG	NA
c740	C_PV_NTH	NA
c745	C_PV_TYPE	NA
c750	C_PV_METHOD	NA
c755	C_PV_FPS	NA
c765	C_VTR_FRAMES	NA
c770	C_VTR_HDTL	NA
c771	C_VTR_HD	NA
c772	C_VTR_TL	NA
c775	C_VTR_IN	NA
c780	C_VTR_PK	NA
c785	C_VTR_SH	NA
c790	C_WORK_MTLS	NA
c792	C_WORK_MTLS_2	NA
c793	C_WORK_MTLS_3	NA
c794	C_WORK_MTLS_4	NA
c7a1	C_BGTYPE	NA
c7b0	C_MEDTILE	NA
c7d0	C_LO_CONTRAST	NA
c7d1	C_HI_CONTRAST	NA
c7e0	C_FROZ_DISPLAY	NA
c7f0	C_BOOLWELD	NA
c7f1	C_BOOLTYPE	NA
c900	C_AND_THRESH	NA
c901	C_SS_THRESH	NA
c903	C_TEXTURE_BLUR_DEFAULT	NA
ca00	C_MAPDRAWER	NA
ca01	C_MAPDRAWER1	NA
ca02	C_MAPDRAWER2	NA
ca03	C_MAPDRAWER3	NA
ca04	C_MAPDRAWER4	NA
ca05	C_MAPDRAWER5	NA
ca06	C_MAPDRAWER6	NA
ca07	C_MAPDRAWER7	NA
ca08	C_MAPDRAWER8	NA
ca09	C_MAPDRAWER9	NA
ca10	C_MAPDRAWER_ENTRY	NA
ca20	C_BACKUP_FILE	NA
ca21	C_DITHER_256	NA
ca22	C_SAVE_LAST	NA
ca23	C_USE_ALPHA	NA
ca24	C_TGA_DEPTH	NA
ca25	C_REND_FIELDS	NA
ca26	C_REFLIP	NA
ca27	C_SEL_ITEMTOG	NA
ca28	C_SEL_RESET	NA
ca29	C_STICKY_KEYINF	NA
ca2a	C_WELD_THRESHOLD	NA
ca2b	C_ZCLIP_POINT	NA
ca2c	C_ALPHA_SPLIT	NA
ca30	C_KF_SHOW_BACKFACE	NA
ca40	C_OPTIMIZE_LOFT	NA
ca42	C_TENS_DEFAULT	NA
ca44	C_CONT_DEFAULT	NA
ca46	C_BIAS_DEFAULT	NA
ca50	C_DXFNAME_SRC	NA
ca60	C_AUTO_WELD	NA
ca70	C_AUTO_UNIFY	NA
ca80	C_AUTO_SMOOTH	NA
ca90	C_DXF_SMOOTH_ANG	NA
caa0	C_SMOOTH_ANG	NA
cb00	C_WORK_MTLS_5	NA
cb01	C_WORK_MTLS_6	NA
cb02	C_WORK_MTLS_7	NA
cb03	C_WORK_MTLS_8	NA
cb04	C_WORKMTL	NA
cb10	C_SXP_TEXT_DATA	NA
cb11	C_SXP_OPAC_DATA	NA
cb12	C_SXP_BUMP_DATA	NA
cb13	C_SXP_SHIN_DATA	NA
cb20	C_SXP_TEXT2_DATA	NA
cb24	C_SXP_SPEC_DATA	NA
cb28	C_SXP_SELFI_DATA	NA
cb30	C_SXP_TEXT_MASKDATA	NA
cb32	C_SXP_TEXT2_MASKDATA	NA
cb34	C_SXP_OPAC_MASKDATA	NA
cb36	C_SXP_BUMP_MASKDATA	NA
cb38	C_SXP_SPEC_MASKDATA	NA
cb3a	C_SXP_SHIN_MASKDATA	NA
cb3e	C_SXP_REFL_MASKDATA	NA
cc00	C_NET_USE_VPOST	NA
cc10	C_NET_USE_GAMMA	NA
cc20	C_NET_FIELD_ORDER	NA
cd00	C_BLUR_FRAMES	NA
cd10	C_BLUR_SAMPLES	NA
cd20	C_BLUR_DUR	NA
cd30	C_HOT_METHOD	NA
cd40	C_HOT_CHECK	NA
cd50	C_PIXEL_SIZE	NA
cd60	C_DISP_GAMMA	NA
cd70	C_FBUF_GAMMA	NA
cd80	C_FILE_OUT_GAMMA	NA
cd82	C_FILE_IN_GAMMA	NA
cd84	C_GAMMA_CORRECT	NA
cd90	C_APPLY_DISP_GAMMA	NA
cda0	C_APPLY_FBUF_GAMMA	NA
cdb0	C_APPLY_FILE_GAMMA	NA
cdc0	C_FORCE_WIRE	NA
cdd0	C_RAY_SHADOWS	NA
cde0	C_MASTER_AMBIENT	NA
cdf0	C_SUPER_SAMPLE	NA
ce00	C_OBJECT_MBUR	NA
ce10	C_MBLUR_DITHER	NA
ce20	C_DITHER_24	NA
ce30	C_SUPER_BLACK	NA
ce40	C_SAFE_FRAME	NA
ce50	C_VIEW_PRES_RATIO	NA
ce60	C_BGND_PRES_RATIO	NA
ce70	C_NTH_SERIAL_NUM	NA
d000	VPDATA	NA
d100	P_QUEUE_ENTRY	NA
d110	P_QUEUE_IMAGE	NA
d114	P_QUEUE_USEIGAMMA	NA
d120	P_QUEUE_PROC	NA
d130	P_QUEUE_SOLID	NA
d140	P_QUEUE_GRADIENT	NA
d150	P_QUEUE_KF	NA
d152	P_QUEUE_MOTBLUR	NA
d153	P_QUEUE_MB_REPEAT	NA
d160	P_QUEUE_NONE	NA
d180	P_QUEUE_RESIZE	NA
d185	P_QUEUE_OFFSET	NA
d190	P_QUEUE_ALIGN	NA
d1a0	P_CUSTOM_SIZE	NA
d210	P_ALPH_NONE	NA
d220	P_ALPH_PSEUDO	NA
d221	P_ALPH_OP_PSEUDO	NA
d222	P_ALPH_BLUR	NA
d225	P_ALPH_PCOL	NA
d230	P_ALPH_CO	NA
d231	P_ALPH_OP_KEY	NA
d235	P_ALPH_KCOL	NA
d238	P_ALPH_OP_NOCONV	NA
d240	P_ALPH_IMAGE	NA
d250	P_ALPH_ALPHA	NA
d260	P_ALPH_QUES	NA
d265	P_ALPH_QUEIMG	NA
d270	P_ALPH_CUTOFF	NA
d280	P_ALPHANEG	NA
d300	P_TRAN_NONE	NA
d310	P_TRAN_IMAGE	NA
d312	P_TRAN_FRAMES	NA
d320	P_TRAN_FADEIN	NA
d330	P_TRAN_FADEOUT	NA
d340	P_TRANNEG	NA
d400	P_RANGES	NA
d500	P_PROC_DATA	NA
f020	POS_TRACK_TAG_KEY	NA
f021	ROT_TRACK_TAG_KEY	NA
f022	SCL_TRACK_TAG_KEY	NA
f023	FOV_TRACK_TAG_KEY	NA
f024	ROLL_TRACK_TAG_KEY	NA
f025	COL_TRACK_TAG_KEY	NA
f026	MORPH_TRACK_TAG_KEY	NA
f027	HOT_TRACK_TAG_KEY	NA
f028	FALL_TRACK_TAG_KEY	NA
f110	POINT_ARRAY_ENTRY	NA
f120	POINT_FLAG_ARRAY_ENTRY	NA
f130	FACE_ARRAY_ENTRY	NA
f140	TEX_VERTS_ENTRY	NA
f150	SMOOTH_GROUP_ENTRY	NA
ffff	DUMMY	NA

Chunk Order

Below is a list of data chunks, and beneath each one a list of chunks or subordinate chunks which usually follow them.

2200 (FOG)

COLOR_F fog_bgnd

2300 (DISTANCE_CUE)

dcue_bgnd (data type unknown)

1200 (SOLID_BGND)

COLOR_F

1300 (V_GRADIENT)

COLOR_F (start of color gradient)

COLOR_F (middle)

COLOR_F (end of gradient)

4600 (N_DIRECT_LIGHT)

COLOR_F

7001 (VIEWPORT_LAYOUT)

VIEWPORT_SIZE

VIEWPORT_DATA

a010 (MAT_AMBIENT)
a020 (MAT_DIFFUSE)
a030 (MAT_SPECULAR)

COLOR_F or COLOR_24

a040 (MAT_SHININESS)
a041 (MAT_SHIN2PCT)
a042 (MAT_SHIN3PCT)
a050 (MAT_TRNSPARENCY)
a052 (MAT_XPFALL)
a053 (MAT_REFBLUR)
a084 (MAT_SELF_ILPCT)

percentage chunk 0030 or 0031

a200 (MAT_TEXMAP)

percentage chunk

MAT_MAPNAME

MAT_MAP_TILING

MAT_MAP_TEXBLUR

possibly other material modifier chunks

a204 (MAT_SPECMAP)
a210 (MAT_OPACMAP)
a220 (MAT_REFLMAP)
a230 (MAT_BUMPMAP)

percentage chunk

MAT_MAPNAME

b000 (KFDATA)

KFHDR

b002 (OBJECT_NODE_TAG)

NODE_HDR

PIVOT

POS_TRACK_TAG

ROT_TRACK_TAG

SCL_TRACK_TAG

possibly others

b003 (CAMERA_NODE_TAG)

NODE_HDR

POS_TRACK_TAG

FOV_TRACK_TAG

ROLL_TRACK_TAG

possibly others

b004 (TARGET_NODE_TAG)

NODE_HDR

POS_TRACK_TAG

possibly others

b005 (LIGHT_NODE_TAG)

NODE_HDR

POS_TRACK_TAG

COL_TRACK_TAG

possibly others

b006 (L_TARGET_NODE_TAG)

NODE_ID

NODE_HDR

POS_TRACK_TAG

b007 (SPOTLIGHT_NODE_TAG)

NODE_ID

NODE_HDR

POS_TRACK_TAG

HOT_TRACK_TAG

FALL_TRACK_TAG

ROLL_TRACK_TAG

COL_TRACK_TAG

possibly others

b00a (KFHDR)

VIEWPORT_LAYOUT

KFSEG

KFCURTIME

OBJECT_NODE_TAG

LIGHT_NODE_TAG

TARGET_NODE_TAG

CAMERA_NODE_TAG

L_TARGET_NODE_TAG

SPOTLIGHT_NODE_TAG

AMBIENT_NODE_TAG

possibly others

Chunk Dependencies

Chunk 4110 (POINT_ARRAY) relies on the following POINT definition:

typedef struct _POINT
{
   FLOAT x, y, z;
} POINT;

Chunk 4120 (FACE_ARRAY) relies on the following FACE definition:

typedef struct _FACE
{
   SHORT vertex1, vertex2, vertex3, flags;
} FACE;

Chunk 4140 (TEX_VERTS) relies on the following VERTEX definition:

typedef struct _VERTEX
{
   FLOAT x,y;
} VERTEX;

Chunk b020 (POS_TRACK_TAG) relies on the following POSITION definition:

typedef struct _POSITION 
{
   SHORT frame_number;
   DWORD unknown;
   FLOAT position_x, position_y, position_z;
} POSITION;

Chunk b021 (ROT_TRACK_TAG) relies on the following ROTATION definition:

typedef struct _ROTATION
{
   SHORT frame_number;
   DWORD unknown;
   FLOAT rotation;         /* in radians */
   FLOAT axis_x, axis_y, axis_z;
} ROTATION;

Chunk b022 (SCL_TRACK_TAG) relies on the following definition of SCALE:

typedef _SCALE
{
   SHORT frame_number;
   DWORD unknown;
   FLOAT scale_x, scale_y, scale_z;
} SCALE;

Chunk b023 (FOV_TRACK_TAG) relies on the following definition of FOV:

typedef _FOV
{
   SHORT frame_number;
   DWORD unknown;
   FLOAT field_of_view;
} FOV

Chunk b024 (ROLL_TRACK_TAG) relies on the following ROLL definition:

typedef _ROLL
{
   SHORT frame_number;
   DWORD unknown;
   FLOAT camera_roll;
} ROLL;

Chunk b025 (COL_TRACK_TAG) relies on the following definition of COLOR:

typedef _COLOR
{
   SHORT frame_number;
   DWORD unknown;
   FLOAT r,g,b;
} COLOR;

Chunk b026 (MORPH_TRACK_TAG) relies on the following definition of MORPH:

typedef _MORPH
{
   SHORT frame_number;
   DWORD unknown;
   CHAR  object_name[]; /* 0-terminated ASCII string */
} MORPH;

Chunk b027 (HOT_TRACK_TAG) relies on the following definition of HOTSPOT:

typedef _HOTSPOT
{
   SHORT frame_number;
   DWORD unknown;
   FLOAT falloff_angle;
} HOTSPOT;

ASC File Example

This is a definition of a cube, centered at the origin, and saved in 3D Studio ASC format:

Ambient light color: Red=0.3 Green=0.3 Blue=0.3
Named object: "Cube"
Tri-mesh, Vertices: 8     Faces: 12
Vertex list:
Vertex 0:  X:-1.000000     Y:-1.000000     Z:0.000000
Vertex 1:  X:-1.000000     Y:-1.000000     Z:2.000000
Vertex 2:  X:1.000000     Y:-1.000000     Z:0.000000
Vertex 3:  X:1.000000     Y:-1.000000     Z:2.000000
Vertex 4:  X:-1.000000     Y:1.000000     Z:0.000000
Vertex 5:  X:1.000000     Y:1.000000     Z:0.000000
Vertex 6:  X:1.000000     Y:1.000000     Z:2.000000
Vertex 7:  X:-1.000000     Y:1.000000     Z:2.000000
Face list:
Face 0:    A:2 B:3 C:1 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 1:    A:2 B:1 C:0 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 2:    A:4 B:5 C:2 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 3:    A:4 B:2 C:0 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 4:    A:6 B:3 C:2 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 5:    A:6 B:2 C:5 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 6:    A:6 B:7 C:1 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 7:    A:6 B:1 C:3 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 8:    A:6 B:5 C:4 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 9:    A:6 B:4 C:7 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 10:    A:1 B:7 C:4 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1
Face 11:    A:1 B:4 C:0 AB:1 BC:1 CA:1
Material:"r210g210b210a0"
Smoothing:  1

For Further Information

Autodesk sells a package that includes documentation on the 3DS file format. Please contact them for further details.

Autodesk Developer Marketing
2320 Marinship Way
Sausalito, CA 94965
Voice: 415-491-8719
WWW: http://www.autodesk.com

Information in this article was obtained from the following two documents:

Lewis, Jeff, The Unofficial 3D Studio 3DS File Format, v1.0, 1 December 1995.

Pitts, Jim, 3D Studio File Format (3dS), Document Revision 0.8, 18 December 1994.

These can be found at:

http://www.europa.com/~keithr/

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