This little tool converts Quake's .bsp to Wrack's .map format. The converter includes geometry, entity and texture conversion. Entity and texture references can be found in two seperate text files. So far I've only done Quake's shareware textures, you'll have to add licensed and custom textures yourself.

This looks awfully familiar.

Technical Details

The first step is to dissect Quake's level format. Thankfully this format was published centuries ago and can be found here. The converter will break down every vertex, brush, and entity. Now we have a collection of data we'd like to convert to Wrack's level format.

Wrack's level format had to be reverse engineered. It's not completely documented yet, but below is a table of all the relevant data required for the converter. Keep note that Wrack strings use a 2-byte prefix indicating its length and is then followed by that number of characters.

wrack_header_t
uint32_t magic_number MMAP
uint32_t map_version 25
wrack_string_tmap_name
wrack_string_tstoryboard_name
wrack_string_tskybox_name
wrack_string_tnext_map_name
uint16_t par_time
uint32_t par_score
uint16_t quickplay_order
wrack_string_tauthor_name
wrack_string_tmusic_file_name
wrack_string_tboss_music_file_name
wrack_string_tambient_sound_file_name
float ambient_sound_volume
boolean is_fog_enabled
uint32_t rgba_fog_colour Alpha is unused
float fog_start
float fog_end
uint32_t map_flags
uint32_t vertex_count
uint32_t face_count
uint32_t zone_count
uint32_t ground_count
uint32_t thing_count

Next up is all the vertex data. Wrack vertices are all stored sequentially as 22-byte structs. The number of vertices stored is based on the vertex count variable found in the header, so you're gonna have to iterate through these.

wrack_vertex_t
int16_t x
int16_t y
int16_t z
float texture_coord_u
float texture_coord_v
float lightmap_coord_u
float lightmap_coord_u

After vertices comes the face data. A Wrack face is a collection of vertices that form a polygon. Just like vertices, these are stored sequentially and must be iterated through.

wrack_face_t
uint32_t vertex_count
uint32_t* vertex_index One index for every vertex
uint32_t face_flags
wrack_string_ttexture_file_name
float texture_rotation
float texture_x_scale
float texture_y_scale
float texture_x_offset
float texture_y_offset
boolean is_texture_x_flipped
boolean is_texture_y_flipped
uint8_t texture_plane_type
uint8_t light
uint32_t rgba_light_colour
float friction
uint32_t unknown_1 Unknown
wrack_string_taction
uint8_t activation_type
uint8_t activated_by
uint8_t tag
uint8_t unknown_2 Unknown
wrack_string_targument_1
wrack_string_targument_2
wrack_string_targument_3
wrack_string_targument_4
wrack_string_targument_5
uint32_t fx_flags
uint32_t rgba_fog_colour Actually saved as BGRA
float fx_start
float fx_end

Whew, that was a big one. Up next are non-geometry data collections. The converter currently does nothing with these and just writes 20 empty bytes, so it's up to you whether to use it or not.

wrack_zone_t
uint32_t face_count
uint32_t* face_index One index for every face
uint16_t type
uint16_t tag

And the other one.

wrack_group_t
uint32_t face_count
uint32_t* face_index One index for every face

Now back to some more interesting data: things. In the Wrack universe a thing is an entity in the world, like a monster or weapon. Just like vertices, faces, zones and groups, these must are stored sequentially.

wrack_thing_t
wrack_string_tname
wrack_string_tdata Unknown behaviour

As you can see the serialisable data string for things hasn't been figured out yet. It's best to just keep it empty since Wrack is sufficient with the thing name alone. Up next comes a big collection of map scripts, collision data, lightmap information, etc. We'll just let the level editor take care of this, so just write 5 empty bytes to finish it off.

Conclusion

The converter is not perfect. For example, Quake uses more precise coordinates for its vertices, causing some broken vertices and faces in Wrack. Somehow there's also some convex shapes that are allowed in Quake, but not in Wrack. You'll have to fix these faces manually through WrackEd, Wrack's level editor. This tool only converts geometry, entities and textures. Logic behind doors, buttons, spawners, etc. are ignored. It will also only work for Quake .bsp files. Quake II, Half-Life, and other games that use the same format are not supported.

A cool thing you can do is define the entity and texture conversion. By editing EntityList and TextureList you decide what you're converting. You could change all Quake Zombies into Wrack Bazookas if you want to. Below is a download link if you'd like to give it a whirl.

Download Quake2Wrack
Source code

And here are Steam workshop items for Wrack made with Quake2Wrack and its predecessor.



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