Crunched Animation Formats

Discussion in 'Guides and Tutorials' started by [V] RabbleRooster, Jan 2, 2018.

  1. [V] RabbleRooster

    [V] RabbleRooster Volition Staff

    This post is like the mesh one, except I *should* understand these better (although, quite frankly, everything has changed since then).

    Rigs are the listing of bones, their parents, and the positional relationship in a T-pose (there's no rotation data in a crunched rig):
    Code (Text):
    struct anim_tag {
        V_FILE_PTR(char *)    name;
        et_fl_matrix43            transformation;
        et_int                    parent_index;
        et_int                    vid;

    // base bone
    class anim_bone {
        V_FILE_PTR(char *)    name;
        et_fl_vector            inv_translation;        //Relative to the skin pivot
        et_fl_vector            rel_bone_translation;    //Relative to the parent
        et_int                    parent_index;
        et_int                    vid;

    class anim_rig {
        char                name[ANIMLIB_MAX_ANIM_RIG_NAME_LEN];
        et_uint            flags;
        et_int            num_bones;
        et_int            num_common_bones;
        et_int            num_virtual_bones;
        et_int            num_tags;

        V_FILE_PTR(uint32 *)    bone_name_chksums;
        V_FILE_PTR(anim_bone    *) bones;
        V_FILE_PTR(anim_tag *)  tags;

    Here's the header for the anim file:
    Code (Text):
    #define AFF_PACKED_KEYS                    (1<<0) // tightly packed rotation keys
    #define AFF_TIME_AS_SHORTS                (1<<1) // time is stored as shorts instead of chars
    #define AFF_DELTA_TIMES                    (1<<2) // animation times are stored as deltas
    #define AFF_HAS_MOTION                    (1<<3) // animation has motion information
    #define AFF_HAS_MORPH                    (1<<4) // animation has morph information
    #define AFF_LONG_TRANSLATIONS            (1<<5) // animation has animated bones that extend beyond 512 meters
    #define AFF_HAS_WEIGHT_KEYS            (1<<6) // animation has weight keys
    #define AFF_SHORT_COUNTS                (1<<7) // animation has more than 255 rotation or translational keyframes
    #define AFF_HAS_SCALE_KEYS                (0) // animation has scale keys

    struct anim_file {
        et_int32        id;
        uint8            version;
        uint8            flags; // see AFF_* above
        et_uint16    end_frame;

        uint8            ramp_in;                        // ramp in  (in MAX ticks)
        uint8            ramp_out;                    // ramp out (in MAX ticks)
        uint8            num_bones;                    // number of animated bones (those with keyframes - even if identity)
        uint8            num_rig_bones;                // num_rig_bones when anim was crunched.

        et_fl_quaternion        total_rotation;
        et_fl_vector            total_translation;

        V_FILE_PTR(uint8 *) anim_to_rig_bone_mapping;    // array of size ANIM_LIB_CFG_MAX_BONES
        V_FILE_PTR(uint8 *) root_controller_bone;        // pointer to the bone data for the root controller.  All other bones have to be stepped through in code
        uint8            data[0];
    The actual animation key data is packed in some really funky ways (spelling mistakes and all). Here are the relevant types:
    Code (Text):
    struct char_quat {
        int8 x, y, z;

    // a packed rotation offset
    // a b and c components represent the 3 smallest values of a quaternion.
    #if defined(__PC)
    struct afc_rotation_offset {
        int8 a                    : 6;
        uint8 a_scaler_bits    : 2;
        int8 b                    : 6;
        uint8 b_scaler_bits    : 2;
        int8 c                    : 6;
        uint8 c_scaler_bits    : 2;

        uint8 count                : 6;
        uint8 largest            : 2;
    struct afc_rotation_offset {
        uint8 a_scaler_bits    : 2;
        int8 a                    : 6;
        uint8 b_scaler_bits    : 2;
        int8 b                    : 6;
        uint8 c_scaler_bits    : 2;
        int8 c                    : 6;

        uint8 largest            : 2;
        uint8 count                : 6;

    // data is packed into 4 6 bit values.
    // easiest way to retrieve is to cast data to an int pointer and copy, then do manipulation
    // xbox2:    | x:6 bits | y:6 bits | z:6 bits | time:6 bits | junk: 8 bits |
    // pc/ps3:    | junk: 8 bits | x:6 bits | y:6 bits | z:6 bits | time:6 bits |

    // byte 0 : | x:6  |y:2|
    // byte 1 : | y:4 | z:4|
    // byte 2 : |z:2|time:6|

    // in order to preserve the sign bit, first shift all the bits to the far left before shifting 26 bits back to the far right. (26 = 32 - 6)
    class afc_rotation_key_packed {
        uint8 data[3];
        inline int get_time() {
            return (data[2] & 0x3f);
        inline int get_a() {
            return (((int)(data[0] << 24)) >> 26);
        inline int get_b() {
            return (((int)((data[0] << 30) | ((data[1] & 0xf0) << 22))) >> 26);
        inline int get_c() {
            return (((int)((data[1] << 28) | ((data[2] & 0xc0) << 20))) >> 26);


    struct afc_rotation_key {
        char_quat rotation;

    // in millimeter units, so a char can represent +/- 127 millimeters
    struct afc_translation_key {
        char x;
        char y;
        char z;

    // in 1 / 64 meter units, so a short can represent +/- 512 meters
    struct afc_translation_offset {
        uint16 num_keys;
        int16 x;
        int16 y;
        int16 z;

    struct afc_translation_offset_long {
        uint32 num_keys;
        int32 x;
        int32 y;
        int32 z;

    struct afc_scale_key {
        fl_vector scale;

    struct afc_weight_key {
        float weight;

    struct afc_morph_key {
        uint8 weight;
    If there is interest, I can do a bit to demystify the storage of all this data in the future.

    Here's the data structures for cloth sim files (there may be some header before the main cloth_sim_info struct):

    Code (Text):
    struct simulated_node_info {
        int8 bone_index;
        int8 parent_node_index;    // rotation is applied to the parent bone for each particle
        int8 gravity_link;
        int8 anchor;

        uint32 collide;        // binary list of colliders that this node collides with.

        float wind_multiplier;
        xxx_vector_conv pos;
        xxx_vector_conv local_space_pos;

    struct simulated_node_link_info {
        uint16 node_index_1;
        uint16 node_index_2;

        uint32 collide;        // bit list of colliders that this linke collides with

        float    length;
        float stretch_len;
        float twist;
        float spring;
        float damp;

    struct cloth_sim_collision_primitive_info {
        int    bone_index;
        short    is_capsule;
        short    do_scale;
        float    radius;
        float    height;
        xxx_vector_conv pos;
        xxx_vector_conv axis;
        xxx_vector_conv local_space_pos;

    struct cloth_sim_rope_info {
        float    length;
        int    num_nodes;
        int    num_links;
        int    *node_indecies;
        int    *link_indecies;

    struct cloth_sim_info {
        int    version;
        int    data_size;
        char  name[28];
        int    num_passes;
        float    air_resistance;
        float wind_multiplier;
        float wind_const;  
        float    gravity_multiplier;
        float object_velocity_inheritance;
        float object_position_inheritance;
        float object_rotation_inheritance;
        int    wind_type;

        int    num_nodes;
        int    num_anchor_nodes;
        int    num_node_links;
        int    num_ropes;
        int    num_colliders;

        simulated_node_info                *nodes;
        simulated_node_link_info        *node_links;
        cloth_sim_rope_info                *ropes;
        cloth_sim_collision_primitive_info *colliders;

    Finally, I'll add morph information here:
    Code (Text):
    struct rl_morph_target_data {
        et_uint                                    name_chksum;
        et_uint                                    num_vbuffers;
        V_FILE_PTR(rl_morph_buffer_generic *) vbuffers; //type is given by target_format in parent structure

    struct rl_morph_data {
        et_int                            signature;
        et_int                            version;

        et_int                            target_format;
        et_int                            num_targets;
        V_FILE_PTR(rl_morph_target_data *) targets;

    class rl_morph_container : public rl_base_object {
        uint32    m_debug_signature;
        rl_morph_data                *m_morph_data;

    struct mesh_morph {
        et_int                        signature;
        et_int                        version;

        V_FILE_PTR(rl_morph_container *)    morph_target;
    Henry08, Quantum, Yepoleb and 3 others like this.
  2. flow754

    flow754 Modding patch tester

    Just when I started trying to RE the anim format myself! This should make it a lot simpler :)
  3. What is wrong with int8 bone_index in cloth sim files? In almost all files which I've opened, I find that first index is 44 in hex and 68 in decimal, character template has 69 bones where the last index is 70 because cont begins with 2. 68 and 69 indexes belong to breast bones. Is it some engine manipulation to increment indexes? How game deal with same indexes?
  4. flow754

    flow754 Modding patch tester

    As far as I know, the bone ID you see in the DCC software is only used to determine the order of the bones, so the bone with the highest ID, regardless of whether it's 70 or 200, will get the last index. If a rig consists of 69 bones, the last index is 68 because indices are zero-based. I'm guessing bones in the sim files are ordered last to first? Would make sense if the converter ordered the bones using some sort of last-in-first-out data structure.
  5. From what I saw in files, sim bones are always additional even for the breast simulation dev used additional bones(at least for NPCs), so it's a logical way to start count them from last bone and increment index to other but SDK converter stop working when finding some index duplication. Also, I am not so sure does female character has crouch bone, but if not it should have 68 bones however sim files for the female and male character are the same.
    I am using now a totally heuristic method because indexes are lower than it should be for the converter.
  6. I wanna know how I can edit those anim_pc, I noticed that the files "plym_bs_sprjmp_pnchattk.anim_pc" and "plym_bs_sprjmp_pnchattkup.anim_pc" have the same size with only little differences in hex, and are respectively about 2 Death From Above animations, "superjump punch attack" and "superjump vehicle attack", the only difference is that each file makes the character animate in different directions, the first with a small inclination and the second to the ground direction, is there a way to create a third file that can change it for horizontal direction?
  7. flow754

    flow754 Modding patch tester

    That's an interesting find! Unfortunately there are no tools to do this easily, but you could use a Hex editor and the information in the OP to change those values manually.
    dragonfly10 likes this.
  8. Already trying, hope I find the right values soon. If I could decompress the anim_pc file would be great.
    Last edited: May 19, 2019 at 11:00 AM
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