110 lines
2.8 KiB
Markdown
110 lines
2.8 KiB
Markdown
# VEC3 format specification
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3D models binary format.
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Byteorder: little-endian
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## Syntax
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```cpp
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enum AttributeType:uint8 {
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POSITION = 0,
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UV,
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NORMAL,
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COLOR,
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};
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sizeof(AttributeType) == 1;
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struct VertexAttribute {
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AttributeType type; // data type is infered from attribute type
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uint8 flags;
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uint32 size;
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float data[]; // if compressed, first 4 bytes of compressed data is decompressed size
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};
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sizeof(VertexAttribute) == 6; // + dynamic data array
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struct Mesh {
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uint32 triangle_count; // number of mesh triangles
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uint16 material_id;
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uint16 flags;
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uint16 attribute_count;
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VertexAttribute attributes[];
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uint8 indices[]; // if compressed, first 4 bytes of compressed data is compressed buffer size
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};
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sizeof(Mesh) == 10; // + dynamic attributes array + dynamic indices array
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struct Model {
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uint16 name_len;
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vec3 origin;
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uint32 mesh_count;
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Mesh meshes[];
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char name[];
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};
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sizeof(Model) == 18; // + dynamic Mesh array + name length
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struct Material {
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uint16 flags;
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uint16 name_len;
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char name[];
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};
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sizeof(Material) == 4; // + dynamic sized string
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struct Header {
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char[8] ident; // "\0\0VEC3\0\0"
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uint16 version; // current is 1
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uint16 reserved; // 0x0000
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};
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sizeof(Header) == 12;
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struct Body {
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uint16 material_count
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uint16 model_count
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Material materials[];
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Model models[];
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};
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sizeof(Body) == 4; // + dynamic models array + dynamic materials array
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```
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\* vertex data: positions are global. Model origins used to make it local.
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vertex - is a set of vertex data section entries indices divided by stride, starting from 0 (section first entry).
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Example: in file having sections (coordinates, texture_coordinates, normal) vertex is a set of 3 indices ordered the
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same way as sections stored in the file.
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## Vertex Data section tags
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All sections are optional.
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| Value | Name | Stride (bytes) | Description |
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| ----- | ------------------- | -------------- | --------------------------- |
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| %x01 | Coordinates | 12 | vertex position |
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| %x02 | Texture coordinates | 8 | vertex texture coordinates |
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| %x03 | Normals | 12 | vertex normal vector |
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| %x04 | Color | 16 | vertex RGBA color (0.0-1.0) |
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VertexAttribute flags:
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| Value | Name |
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| ----- | ---------------- |
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| %x01 | ZLib compression |
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## Mesh
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Mesh flags:
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| Value | Name |
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| ----- | ----------------------------------- |
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| %x01 | Indices ZLib compression |
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| %x02 | Use 16 bit indices instead of 8 bit |
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## Material
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Material flags:
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| Bit offset | Description |
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|------------|-------------|
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| 0 | Shadeless |
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| 1-7 | Reserved |
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