ShadowEnvironments

[snake-biscuits]

Titanfall 2 introduces the light_environment_volume entity
By creating a group entity out of triggers, the mapper can define a region of map which uses it's own light_environment

sp_crashsite ("BT-7274"), the first map of the campaign utilises this to have both day & night segments in the same map.

[snake-biscuits]

from before identifying patterns:

// sp_skyway_v1
int[6] + char[12]
// X1 |  Y1 | Z1 | X2 |  Y2 | Z2 | char[12]
[(   0,    0,  0, 3818, 5890, 22, F4 67 63 BF 78 50 5E BE 93 34 CF BE),
 (3818, 5890, 22, 3819, 5892, 23, DB 66 21 BF D6 39 DA 3E 5F 12 26 BF),
 (3819, 5892, 23, 3931, 5985, 24, 76 8A 60 3F 30 A2 D8 3E 25 B8 68 BE),
 (3931, 5985, 24, 3989, 6185, 25, 83 D1 32 3F 76 D6 03 3F 49 64 FE BE)]
// ^ " ".join([f"{i:02X}" for i in char_12])

struct Abstract {
  uint32_t first_[3];
  uint32_t num_[3];
  Vector   sun_normal;
};

Identifed structure:

struct ShadowEnvironment {
  int32_t first_unknown[2];
  int32_t first_shadow_mesh;
  int32_t num_unknown[2];
  int32_t num_shadow_meshes;
  float   angle_vector[3];
};

[snake-biscuits]

Later did some trigonometry to confirm sun_normals matched light_environment angles
Can't find my notes from this

[snake-biscuits]

Old video from BobTheBob: hex-editing ShadowEnvironments on mp_angel_city:

r2_angel_city_modded_SHADOW_ENVIRONMENTS.webm

[snake-biscuits]

Sun normal vectors seem to control CSM shadow calculation (projection angle)
If the vector isn't normalised, shadows become disconnected from dynamic models

[snake-biscuits]

Generating a sun_normal is pretty simple:

# bsp_tool.extensions.convert.respawn
# ShadowEnvironment
light_env = [e for e in r1_bsp.ENTITIES if e["classname"] == "light_environment"][0]  # get sun
# get angles, with defaults
pitch, yaw, roll = map(float, light_env.get("angles", "0 0 0").split())
pitch = float(light_env.get("pitch", pitch))  # pitch key overrides; TODO: unless 0 (default value)
# rotate default vector (east) in angles order
sun_vector = vec3(1, 0, 0).rotate(y=pitch)
sun_vector = sun_vector.rotate(z=yaw)
# generate a basic ShadowEnvironment
shadow_env = r2.ShadowEnvironment(
    first_csm_aabb_node=0, first_csm_obj_reference=0, first_shadow_mesh=0,
    last_csm_aabb_node=1, last_csm_obj_reference=0, last_shadow_mesh=len(r1_bsp.SHADOW_MESHES),
    sun_normal=sun_vector)
r1_bsp.SHADOW_ENVIRONMENTS = [shadow_env]
light_env["lightEnvironmentIndex"] = "*0"