render3d: the survey DEM is let go once the height field is made, and the terrain sun shadow is R32F + RG16F

The DEM (R16 with mips, 44 MB) was read only by terrain_generate and kept for the map's life; a
world swap loads its own again. The height-field sun shadow was one RGBA32F for three values and an
unused fourth: the lowest lit height stays 32-bit (a receiver 3000 m up compares against it to a
quarter metre), the occluder distance and the cloud mask go beside it in RG16F (64 -> 32 MB), baked
in a pass of their own (TS_AUX): a pipeline takes one colour format for all its targets, and drawn
together into R32F + RG16F the writes went nowhere and nothing was lit.

-75 MB at every fog level, off included (2008 -> 1933 MB at the overlook); the fog-off frame is
unchanged (0 pixels over 8).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

packages/ludic.render3d/env.ludic

@@ -828,7 +828,9 @@ export state Render3dState {
   ter_dem_base: float = 0.0
   ter_ortho_tex: int = 0            # a photograph of the same window, draped with distance
   ter_carpet: int = 0               # the distant-grass carpet (carpet_bake), 0 = none
-  ter_shadow_tex: int = 0           # height-field sun shadow: RG32F (lowest lit height, occluder distance)
+  ter_shadow_tex: int = 0           # height-field sun shadow: R32F, the lowest lit height
+  ter_shadow_prog_aux: int = 0      # the bake of the aux target (TS_AUX)
+  ter_shadow_aux: int = 0           # beside it, RG16F: the occluder distance and the cloud mask
   ter_shadow_yaw: float = 1000000000.0  # the sky yaw it was baked for
   ter_shadow_gen: int = -1          # the daylight generation it was baked for
   ter_shadow_prog: int = 0

packages/ludic.render3d/shaders/lighting.glsl

@@ -158,7 +158,8 @@ float shadowSlope(int c, vec3 wpos, vec3 n, float tanT) {
 // ground texel, G = distance to the occluder that set it. Any receiver — ground, crown,
 // card, water — compares its own height, so everything agrees on where the hill's
 // shadow falls. The penumbra widens with the occluder's distance like a real one.
-uniform sampler2D u_tershadow;
+uniform sampler2D u_tershadow;      // R: the lowest lit height
+uniform sampler2D u_tershadow_aux;  // R: the occluder distance, G: the cloud mask
 uniform vec2 u_ts_origin;
 uniform float u_ts_half;
 uniform float u_ts_on;
@@ -177,7 +178,7 @@ float terrainShadow(vec3 wpos) {
   if (u_ts_on < 0.5) return 1.0;
   vec2 uv = (wpos.xz - u_ts_origin) / (2.0 * u_ts_half) + 0.5;
   if (uv.x < 0.0 || uv.x > 1.0 || uv.y < 0.0 || uv.y > 1.0) return 1.0;
-  vec2 s = texture(u_tershadow, uv).rg;
+  vec2 s = vec2(texture(u_tershadow, uv).r, texture(u_tershadow_aux, uv).r);
   float w = 0.6 + 0.02 * s.y;
   return smoothstep(-w, w, wpos.y + 0.25 - s.x);
 }
@@ -219,7 +220,7 @@ float sunShadow(vec3 wpos, vec3 n, float viewDepth) {
 // patchy sunlight: a cloud layer projected along the sun onto the ground
 uniform float u_cloud_shadow;     // strength
 uniform float u_time;
-// the mask is baked into the height-field shadow texture's B (tershadow.frag); the
+// the mask is baked beside the height-field shadow, in its aux texture's G (tershadow.frag); the
 // projection along the sun and the drift are a uv shift
 float cloudShadow(vec3 wpos) {
   if (u_cloud_shadow <= 0.0 || u_ts_on < 0.5) return 1.0;
@@ -228,7 +229,7 @@ float cloudShadow(vec3 wpos) {
   c += vec2(u_time * 3.0, u_time * 1.2);
   vec2 uv = (c - u_ts_origin) / (2.0 * u_ts_half) + 0.5;
   if (uv.x < 0.0 || uv.x > 1.0 || uv.y < 0.0 || uv.y > 1.0) return 1.0;
-  return 1.0 - u_cloud_shadow * texture(u_tershadow, uv).b;
+  return 1.0 - u_cloud_shadow * texture(u_tershadow_aux, uv).g;
 }
 
 // regional vegetation colour: aspen groves and drier ridges read lighter and yellower than

packages/ludic.render3d/shaders/spv/manifest.txt

@@ -49,7 +49,8 @@ T 2ee6d2e3 u_prev 5
 T 2ee6d2e3 u_scene 6
 T 2ee6d2e3 u_shadow 7
 T 2ee6d2e3 u_tershadow 8
-T 2ee6d2e3 u_ts_height 9
+T 2ee6d2e3 u_tershadow_aux 9
+T 2ee6d2e3 u_ts_height 10
 P 9d3e2ddd fullscreen.vert bloom_down.frag 
 B 9d3e2ddd frag 1 844
 U 9d3e2ddd frag u_cascade_vp 0 mat4 5 64
@@ -96,7 +97,8 @@ T 9d3e2ddd u_prefilter 4
 T 9d3e2ddd u_shadow 5
 T 9d3e2ddd u_src 6
 T 9d3e2ddd u_tershadow 7
-T 9d3e2ddd u_ts_height 8
+T 9d3e2ddd u_tershadow_aux 8
+T 9d3e2ddd u_ts_height 9
 P c57b4f14 fullscreen.vert bloom_up.frag 
 B c57b4f14 frag 1 844
 U c57b4f14 frag u_cascade_vp 0 mat4 5 64
@@ -143,7 +145,8 @@ T c57b4f14 u_prefilter 4
 T c57b4f14 u_shadow 5
 T c57b4f14 u_src 6
 T c57b4f14 u_tershadow 7
-T c57b4f14 u_ts_height 8
+T c57b4f14 u_tershadow_aux 8
+T c57b4f14 u_ts_height 9
 P 5161e6ba fullscreen.vert dof.frag 
 B 5161e6ba frag 1 916
 U 5161e6ba frag u_cascade_vp 0 mat4 5 64
@@ -194,7 +197,8 @@ T 5161e6ba u_prefilter 5
 T 5161e6ba u_shadow 6
 T 5161e6ba u_src 7
 T 5161e6ba u_tershadow 8
-T 5161e6ba u_ts_height 9
+T 5161e6ba u_tershadow_aux 9
+T 5161e6ba u_ts_height 10
 P 4be7acd9 fullscreen.vert heightgen.frag #define DEM;
 B 4be7acd9 frag 1 920
 U 4be7acd9 frag u_cascade_vp 0 mat4 5 64
@@ -251,7 +255,8 @@ T 4be7acd9 u_irradiance 4
 T 4be7acd9 u_prefilter 5
 T 4be7acd9 u_shadow 6
 T 4be7acd9 u_tershadow 7
-T 4be7acd9 u_ts_height 8
+T 4be7acd9 u_tershadow_aux 8
+T 4be7acd9 u_ts_height 9
 P 858f5089 fullscreen.vert ibl_brdf.frag 
 B 858f5089 frag 0 832
 U 858f5089 frag u_cascade_vp 0 mat4 5 64
@@ -295,7 +300,8 @@ T 858f5089 u_irradiance 3
 T 858f5089 u_prefilter 4
 T 858f5089 u_shadow 5
 T 858f5089 u_tershadow 6
-T 858f5089 u_ts_height 7
+T 858f5089 u_tershadow_aux 7
+T 858f5089 u_ts_height 8
 P e18e40c9 fullscreen.vert ibl_irradiance.frag 
 B e18e40c9 frag 1 836
 U e18e40c9 frag u_cascade_vp 0 mat4 5 64
@@ -341,7 +347,8 @@ T e18e40c9 u_prefilter 4
 T e18e40c9 u_shadow 5
 T e18e40c9 u_sky 6
 T e18e40c9 u_tershadow 7
-T e18e40c9 u_ts_height 8
+T e18e40c9 u_tershadow_aux 8
+T e18e40c9 u_ts_height 9
 P 638623c2 fullscreen.vert ibl_prefilter.frag 
 B 638623c2 frag 1 844
 U 638623c2 frag u_cascade_vp 0 mat4 5 64
@@ -389,7 +396,8 @@ T 638623c2 u_prefilter 4
 T 638623c2 u_shadow 5
 T 638623c2 u_sky 6
 T 638623c2 u_tershadow 7
-T 638623c2 u_ts_height 8
+T 638623c2 u_tershadow_aux 8
+T 638623c2 u_ts_height 9
 P 4cf96468 fullscreen.vert sharpen.frag 
 B 4cf96468 frag 1 852
 U 4cf96468 frag u_cascade_vp 0 mat4 5 64
@@ -438,7 +446,8 @@ T 4cf96468 u_prefilter 4
 T 4cf96468 u_shadow 5
 T 4cf96468 u_src 6
 T 4cf96468 u_tershadow 7
-T 4cf96468 u_ts_height 8
+T 4cf96468 u_tershadow_aux 8
+T 4cf96468 u_ts_height 9
 P 428caa3a fullscreen.vert sky.frag 
 B 428caa3a frag 1 940
 U 428caa3a frag u_cascade_vp 0 mat4 5 64
@@ -491,7 +500,8 @@ T 428caa3a u_prefilter 4
 T 428caa3a u_shadow 5
 T 428caa3a u_sky 6
 T 428caa3a u_tershadow 7
-T 428caa3a u_ts_height 8
+T 428caa3a u_tershadow_aux 8
+T 428caa3a u_ts_height 9
 P 3e4b62f9 fullscreen.vert ssao_blur.frag 
 B 3e4b62f9 frag 1 840
 U 3e4b62f9 frag u_cascade_vp 0 mat4 5 64
@@ -538,7 +548,8 @@ T 3e4b62f9 u_irradiance 5
 T 3e4b62f9 u_prefilter 6
 T 3e4b62f9 u_shadow 7
 T 3e4b62f9 u_tershadow 8
-T 3e4b62f9 u_ts_height 9
+T 3e4b62f9 u_tershadow_aux 9
+T 3e4b62f9 u_ts_height 10
 P 676965ab fullscreen.vert ssgi.frag 
 B 676965ab frag 1 984
 U 676965ab frag u_cascade_vp 0 mat4 5 64
@@ -591,7 +602,8 @@ T 676965ab u_prefilter 5
 T 676965ab u_prev_color 6
 T 676965ab u_shadow 7
 T 676965ab u_tershadow 8
-T 676965ab u_ts_height 9
+T 676965ab u_tershadow_aux 9
+T 676965ab u_ts_height 10
 P a45356c7 fullscreen.vert ternormal.frag 
 B a45356c7 frag 1 836
 U a45356c7 frag u_cascade_vp 0 mat4 5 64
@@ -637,7 +649,8 @@ T a45356c7 u_prefilter 4
 T a45356c7 u_shadow 5
 T a45356c7 u_src 6
 T a45356c7 u_tershadow 7
-T a45356c7 u_ts_height 8
+T a45356c7 u_tershadow_aux 8
+T a45356c7 u_ts_height 9
 P 4a8e9f28 fullscreen.vert tershadow.frag #define NOISE_ONLY;
 B 4a8e9f28 frag 1 860
 U 4a8e9f28 frag u_cascade_vp 0 mat4 5 64
@@ -684,7 +697,56 @@ T 4a8e9f28 u_irradiance 4
 T 4a8e9f28 u_prefilter 5
 T 4a8e9f28 u_shadow 6
 T 4a8e9f28 u_tershadow 7
-T 4a8e9f28 u_ts_height 8
+T 4a8e9f28 u_tershadow_aux 8
+T 4a8e9f28 u_ts_height 9
+P 3a1797ab fullscreen.vert tershadow.frag #define NOISE_ONLY;#define TS_AUX;
+B 3a1797ab frag 1 860
+U 3a1797ab frag u_cascade_vp 0 mat4 5 64
+U 3a1797ab frag u_cascade_split 320 float 5 16
+U 3a1797ab frag u_cascade_range 400 float 5 16
+U 3a1797ab frag u_cascade_texel 480 float 5 16
+U 3a1797ab frag u_sun_dir 560 vec3 1 0
+U 3a1797ab frag u_sun_color 576 vec3 1 0
+U 3a1797ab frag u_cam_pos 592 vec3 1 0
+U 3a1797ab frag u_prefilter_levels 604 float 1 0
+U 3a1797ab frag u_fog_density 608 float 1 0
+U 3a1797ab frag u_fog_height_falloff 612 float 1 0
+U 3a1797ab frag u_fog_base 616 float 1 0
+U 3a1797ab frag u_clip_y 620 float 1 0
+U 3a1797ab frag u_spec_scale 624 float 1 0
+U 3a1797ab frag u_sky_rot 632 vec2 1 0
+U 3a1797ab frag u_ground_alb 640 vec3 1 0
+U 3a1797ab frag u_ground_alb_hi 656 vec3 1 0
+U 3a1797ab frag u_ground_hi_y 668 float 1 0
+U 3a1797ab frag u_ground_hi_w 672 float 1 0
+U 3a1797ab frag u_ibl_scale 688 vec3 1 0
+U 3a1797ab frag u_daylight 700 float 1 0
+U 3a1797ab frag u_fire_pos 704 vec3 1 0
+U 3a1797ab frag u_fire_color 720 vec3 1 0
+U 3a1797ab frag u_hand_pos 736 vec3 1 0
+U 3a1797ab frag u_hand_color 752 vec3 1 0
+U 3a1797ab frag u_hand_dir 768 vec3 1 0
+U 3a1797ab frag u_hand_cone 780 float 1 0
+U 3a1797ab frag u_hand_reach 784 float 1 0
+U 3a1797ab frag u_ts_origin 792 vec2 1 0
+U 3a1797ab frag u_ts_half 800 float 1 0
+U 3a1797ab frag u_ts_on 804 float 1 0
+U 3a1797ab frag u_force_cascade 808 int 1 0
+U 3a1797ab frag u_cloud_shadow 812 float 1 0
+U 3a1797ab frag u_time 816 float 1 0
+U 3a1797ab frag u_fog_inscatter 820 float 1 0
+U 3a1797ab frag u_fog_desat 824 float 1 0
+U 3a1797ab frag u_fog_wall 828 float 1 0
+U 3a1797ab frag u_half 832 float 1 0
+U 3a1797ab frag u_sun 848 vec3 1 0
+T 3a1797ab u_brdf 2
+T 3a1797ab u_height 3
+T 3a1797ab u_irradiance 4
+T 3a1797ab u_prefilter 5
+T 3a1797ab u_shadow 6
+T 3a1797ab u_tershadow 7
+T 3a1797ab u_tershadow_aux 8
+T 3a1797ab u_ts_height 9
 P 725523d9 fullscreen.vert tonemap.frag 
 B 725523d9 frag 1 916
 U 725523d9 frag u_cascade_vp 0 mat4 5 64
@@ -743,7 +805,8 @@ T 725523d9 u_irradiance 7
 T 725523d9 u_prefilter 8
 T 725523d9 u_shadow 9
 T 725523d9 u_tershadow 10
-T 725523d9 u_ts_height 11
+T 725523d9 u_tershadow_aux 11
+T 725523d9 u_ts_height 12
 P a4683767 fullscreen.vert tonemap.frag #define HDR10;
 B a4683767 frag 1 928
 U a4683767 frag u_cascade_vp 0 mat4 5 64
@@ -805,7 +868,8 @@ T a4683767 u_irradiance 7
 T a4683767 u_prefilter 8
 T a4683767 u_shadow 9
 T a4683767 u_tershadow 10
-T a4683767 u_ts_height 11
+T a4683767 u_tershadow_aux 11
+T a4683767 u_ts_height 12
 P 74258189 fullscreen.vert volumetric.frag 
 B 74258189 frag 1 924
 U 74258189 frag u_cascade_vp 0 mat4 5 64
@@ -858,7 +922,8 @@ T 74258189 u_irradiance 4
 T 74258189 u_prefilter 5
 T 74258189 u_shadow 6
 T 74258189 u_tershadow 7
-T 74258189 u_ts_height 8
+T 74258189 u_tershadow_aux 8
+T 74258189 u_ts_height 9
 P d48d6a48 grass.mesh model.frag #define FOLIAGE;#define BLADE;#define MESH;
 B d48d6a48 vert 0 4388
 U d48d6a48 vert u_view 0 mat4 1 0
@@ -938,7 +1003,8 @@ T d48d6a48 u_prefilter 9
 T d48d6a48 u_shadow 10
 T d48d6a48 u_ter_normal 11
 T d48d6a48 u_tershadow 12
-T d48d6a48 u_ts_height 13
+T d48d6a48 u_tershadow_aux 13
+T d48d6a48 u_ts_height 14
 P cb13f3c6 grass.vert model.frag #define FOLIAGE;#define BLADE;#define GBLADE;
 B cb13f3c6 vert 0 324
 U cb13f3c6 vert u_view 0 mat4 1 0
@@ -1022,7 +1088,8 @@ T cb13f3c6 u_prefilter 9
 T cb13f3c6 u_shadow 10
 T cb13f3c6 u_ter_normal 11
 T cb13f3c6 u_tershadow 12
-T cb13f3c6 u_ts_height 13
+T cb13f3c6 u_tershadow_aux 13
+T cb13f3c6 u_ts_height 14
 P b8cff226 grass.vert model.frag #define FOLIAGE;#define BLADE;#define GBLADE;#define TILES;
 B b8cff226 vert 0 4420
 U b8cff226 vert u_view 0 mat4 1 0
@@ -1107,7 +1174,8 @@ T b8cff226 u_prefilter 9
 T b8cff226 u_shadow 10
 T b8cff226 u_ter_normal 11
 T b8cff226 u_tershadow 12
-T b8cff226 u_ts_height 13
+T b8cff226 u_tershadow_aux 13
+T b8cff226 u_ts_height 14
 P 3733fc38 impostor.vert impostor.frag 
 B 3733fc38 vert 0 232
 U 3733fc38 vert u_view 0 mat4 1 0
@@ -1170,7 +1238,8 @@ T 3733fc38 u_irradiance 5
 T 3733fc38 u_prefilter 6
 T 3733fc38 u_shadow 7
 T 3733fc38 u_tershadow 8
-T 3733fc38 u_ts_height 9
+T 3733fc38 u_tershadow_aux 9
+T 3733fc38 u_ts_height 10
 P 4d4fa91b impostor.vert impostor.frag #define SHADOW_PASS;
 B 4d4fa91b vert 0 232
 U 4d4fa91b vert u_view 0 mat4 1 0
@@ -1233,7 +1302,8 @@ T 4d4fa91b u_irradiance 5
 T 4d4fa91b u_prefilter 6
 T 4d4fa91b u_shadow 7
 T 4d4fa91b u_tershadow 8
-T 4d4fa91b u_ts_height 9
+T 4d4fa91b u_tershadow_aux 9
+T 4d4fa91b u_ts_height 10
 P 9dce3246 model.vert bake.frag 
 B 9dce3246 vert 0 236
 U 9dce3246 vert u_view 0 mat4 1 0
@@ -1297,7 +1367,8 @@ T 9dce3246 u_irradiance 5
 T 9dce3246 u_prefilter 6
 T 9dce3246 u_shadow 7
 T 9dce3246 u_tershadow 8
-T 9dce3246 u_ts_height 9
+T 9dce3246 u_tershadow_aux 9
+T 9dce3246 u_ts_height 10
 P 439a2253 model.vert bake.frag #define CARD;
 B 439a2253 vert 0 236
 U 439a2253 vert u_view 0 mat4 1 0
@@ -1361,7 +1432,8 @@ T 439a2253 u_irradiance 5
 T 439a2253 u_prefilter 6
 T 439a2253 u_shadow 7
 T 439a2253 u_tershadow 8
-T 439a2253 u_ts_height 9
+T 439a2253 u_tershadow_aux 9
+T 439a2253 u_ts_height 10
 P 86f427b0 model.vert bake.frag #define FLOWER;
 B 86f427b0 vert 0 236
 U 86f427b0 vert u_view 0 mat4 1 0
@@ -1425,7 +1497,8 @@ T 86f427b0 u_irradiance 5
 T 86f427b0 u_prefilter 6
 T 86f427b0 u_shadow 7
 T 86f427b0 u_tershadow 8
-T 86f427b0 u_ts_height 9
+T 86f427b0 u_tershadow_aux 9
+T 86f427b0 u_ts_height 10
 P bfa15301 model.vert depth.frag #define FOLIAGE;#define WIND;#define ALPHA_TEST;
 B bfa15301 vert 0 236
 U bfa15301 vert u_view 0 mat4 1 0
@@ -1488,7 +1561,8 @@ T bfa15301 u_irradiance 4
 T bfa15301 u_prefilter 5
 T bfa15301 u_shadow 6
 T bfa15301 u_tershadow 7
-T bfa15301 u_ts_height 8
+T bfa15301 u_tershadow_aux 8
+T bfa15301 u_ts_height 9
 P 266d2401 model.vert depth.frag #define FOLIAGE;#define WIND;#define ALPHA_TEST;#define NEAR_FADE;
 B 266d2401 vert 0 236
 U 266d2401 vert u_view 0 mat4 1 0
@@ -1551,7 +1625,8 @@ T 266d2401 u_irradiance 4
 T 266d2401 u_prefilter 5
 T 266d2401 u_shadow 6
 T 266d2401 u_tershadow 7
-T 266d2401 u_ts_height 8
+T 266d2401 u_tershadow_aux 8
+T 266d2401 u_ts_height 9
 P 01089da8 model.vert model.frag 
 B 01089da8 vert 0 236
 U 01089da8 vert u_view 0 mat4 1 0
@@ -1622,7 +1697,8 @@ T 01089da8 u_nrm 7
 T 01089da8 u_prefilter 8
 T 01089da8 u_shadow 9
 T 01089da8 u_tershadow 10
-T 01089da8 u_ts_height 11
+T 01089da8 u_tershadow_aux 11
+T 01089da8 u_ts_height 12
 P 254e7887 model.vert model.frag #define CARD;#define CHEAP;
 B 254e7887 vert 0 236
 U 254e7887 vert u_view 0 mat4 1 0
@@ -1694,7 +1770,8 @@ T 254e7887 u_nrm 7
 T 254e7887 u_prefilter 8
 T 254e7887 u_shadow 9
 T 254e7887 u_tershadow 10
-T 254e7887 u_ts_height 11
+T 254e7887 u_tershadow_aux 11
+T 254e7887 u_ts_height 12
 P 1ce5c5d1 model.vert model.frag #define FOLIAGE;#define WIND;#define ALPHA_TEST;
 B 1ce5c5d1 vert 0 236
 U 1ce5c5d1 vert u_view 0 mat4 1 0
@@ -1765,7 +1842,8 @@ T 1ce5c5d1 u_nrm 7
 T 1ce5c5d1 u_prefilter 8
 T 1ce5c5d1 u_shadow 9
 T 1ce5c5d1 u_tershadow 10
-T 1ce5c5d1 u_ts_height 11
+T 1ce5c5d1 u_tershadow_aux 11
+T 1ce5c5d1 u_ts_height 12
 P 5e70d731 model.vert model.frag #define FOLIAGE;#define WIND;#define ALPHA_TEST;#define NEAR_FADE;
 B 5e70d731 vert 0 236
 U 5e70d731 vert u_view 0 mat4 1 0
@@ -1836,7 +1914,8 @@ T 5e70d731 u_nrm 7
 T 5e70d731 u_prefilter 8
 T 5e70d731 u_shadow 9
 T 5e70d731 u_tershadow 10
-T 5e70d731 u_ts_height 11
+T 5e70d731 u_tershadow_aux 11
+T 5e70d731 u_ts_height 12
 P f4a2b586 model.vert model.frag #define FOLIAGE;#define WIND;#define BLADE;
 B f4a2b586 vert 0 252
 U f4a2b586 vert u_view 0 mat4 1 0
@@ -1913,7 +1992,8 @@ T f4a2b586 u_nrm 7
 T f4a2b586 u_prefilter 8
 T f4a2b586 u_shadow 9
 T f4a2b586 u_tershadow 10
-T f4a2b586 u_ts_height 11
+T f4a2b586 u_tershadow_aux 11
+T f4a2b586 u_ts_height 12
 P b4587cd4 model.vert model.frag #define FOLIAGE;#define WIND;#define CARD;
 B b4587cd4 vert 0 236
 U b4587cd4 vert u_view 0 mat4 1 0
@@ -1985,7 +2065,8 @@ T b4587cd4 u_nrm 7
 T b4587cd4 u_prefilter 8
 T b4587cd4 u_shadow 9
 T b4587cd4 u_tershadow 10
-T b4587cd4 u_ts_height 11
+T b4587cd4 u_tershadow_aux 11
+T b4587cd4 u_ts_height 12
 P 4dda406a model.vert model.frag #define FOLIAGE;#define WIND;#define EQ_PASS;
 B 4dda406a vert 0 236
 U 4dda406a vert u_view 0 mat4 1 0
@@ -2056,7 +2137,8 @@ T 4dda406a u_nrm 7
 T 4dda406a u_prefilter 8
 T 4dda406a u_shadow 9
 T 4dda406a u_tershadow 10
-T 4dda406a u_ts_height 11
+T 4dda406a u_tershadow_aux 11
+T 4dda406a u_ts_height 12
 P b603a056 model.vert model.frag #define FOLIAGE;#define WIND;#define EQ_PASS;#define NEAR_FADE;
 B b603a056 vert 0 236
 U b603a056 vert u_view 0 mat4 1 0
@@ -2127,7 +2209,8 @@ T b603a056 u_nrm 7
 T b603a056 u_prefilter 8
 T b603a056 u_shadow 9
 T b603a056 u_tershadow 10
-T b603a056 u_ts_height 11
+T b603a056 u_tershadow_aux 11
+T b603a056 u_ts_height 12
 P 3b183d8f model.vert model.frag #define FOLIAGE;#define WIND;#define FLOWER;
 B 3b183d8f vert 0 236
 U 3b183d8f vert u_view 0 mat4 1 0
@@ -2198,7 +2281,8 @@ T 3b183d8f u_nrm 7
 T 3b183d8f u_prefilter 8
 T 3b183d8f u_shadow 9
 T 3b183d8f u_tershadow 10
-T 3b183d8f u_ts_height 11
+T 3b183d8f u_tershadow_aux 11
+T 3b183d8f u_ts_height 12
 P 79b77ed9 model.vert model.frag #define SHADOW_PASS;#define WIND;#define CARD;
 B 79b77ed9 vert 0 236
 U 79b77ed9 vert u_view 0 mat4 1 0
@@ -2270,7 +2354,8 @@ T 79b77ed9 u_nrm 7
 T 79b77ed9 u_prefilter 8
 T 79b77ed9 u_shadow 9
 T 79b77ed9 u_tershadow 10
-T 79b77ed9 u_ts_height 11
+T 79b77ed9 u_tershadow_aux 11
+T 79b77ed9 u_ts_height 12
 P b9fc2041 model.vert model.frag #define WIND;
 B b9fc2041 vert 0 236
 U b9fc2041 vert u_view 0 mat4 1 0
@@ -2341,7 +2426,8 @@ T b9fc2041 u_nrm 7
 T b9fc2041 u_prefilter 8
 T b9fc2041 u_shadow 9
 T b9fc2041 u_tershadow 10
-T b9fc2041 u_ts_height 11
+T b9fc2041 u_tershadow_aux 11
+T b9fc2041 u_ts_height 12
 P f34dce08 model.vert shadow.frag #define SHADOW_PASS;
 B f34dce08 vert 0 236
 U f34dce08 vert u_view 0 mat4 1 0
@@ -2404,7 +2490,8 @@ T f34dce08 u_irradiance 4
 T f34dce08 u_prefilter 5
 T f34dce08 u_shadow 6
 T f34dce08 u_tershadow 7
-T f34dce08 u_ts_height 8
+T f34dce08 u_tershadow_aux 8
+T f34dce08 u_ts_height 9
 P 512004a1 model.vert shadow.frag #define SHADOW_PASS;#define WIND;
 B 512004a1 vert 0 236
 U 512004a1 vert u_view 0 mat4 1 0
@@ -2467,7 +2554,8 @@ T 512004a1 u_irradiance 4
 T 512004a1 u_prefilter 5
 T 512004a1 u_shadow 6
 T 512004a1 u_tershadow 7
-T 512004a1 u_ts_height 8
+T 512004a1 u_tershadow_aux 8
+T 512004a1 u_ts_height 9
 P b964507f model.vert shadow.frag #define SHADOW_PASS;#define WIND;#define ALPHA_TEST;
 B b964507f vert 0 236
 U b964507f vert u_view 0 mat4 1 0
@@ -2530,7 +2618,8 @@ T b964507f u_irradiance 4
 T b964507f u_prefilter 5
 T b964507f u_shadow 6
 T b964507f u_tershadow 7
-T b964507f u_ts_height 8
+T b964507f u_tershadow_aux 8
+T b964507f u_ts_height 9
 P 1b654972 overlay.vert overlay.frag 
 B 1b654972 vert 0 8
 U 1b654972 vert u_screen 0 vec2 1 0
@@ -2580,8 +2669,9 @@ T 1b654972 u_irradiance 4
 T 1b654972 u_prefilter 5
 T 1b654972 u_shadow 6
 T 1b654972 u_tershadow 7
-T 1b654972 u_tex 8
-T 1b654972 u_ts_height 9
+T 1b654972 u_tershadow_aux 8
+T 1b654972 u_tex 9
+T 1b654972 u_ts_height 10
 P e86f78e8 overlay.vert overlay.frag #define HDR10;
 B e86f78e8 vert 0 8
 U e86f78e8 vert u_screen 0 vec2 1 0
@@ -2633,8 +2723,9 @@ T e86f78e8 u_irradiance 4
 T e86f78e8 u_prefilter 5
 T e86f78e8 u_shadow 6
 T e86f78e8 u_tershadow 7
-T e86f78e8 u_tex 8
-T e86f78e8 u_ts_height 9
+T e86f78e8 u_tershadow_aux 8
+T e86f78e8 u_tex 9
+T e86f78e8 u_ts_height 10
 P 1fde9cd2 skin.vert model.frag 
 B 1fde9cd2 vert 0 3344
 U 1fde9cd2 vert u_model 0 mat4 1 0
@@ -2699,7 +2790,8 @@ T 1fde9cd2 u_nrm 7
 T 1fde9cd2 u_prefilter 8
 T 1fde9cd2 u_shadow 9
 T 1fde9cd2 u_tershadow 10
-T 1fde9cd2 u_ts_height 11
+T 1fde9cd2 u_tershadow_aux 11
+T 1fde9cd2 u_ts_height 12
 P a5ad521e skin.vert model.frag #define ALPHA_TEST;
 B a5ad521e vert 0 3344
 U a5ad521e vert u_model 0 mat4 1 0
@@ -2764,7 +2856,8 @@ T a5ad521e u_nrm 7
 T a5ad521e u_prefilter 8
 T a5ad521e u_shadow 9
 T a5ad521e u_tershadow 10
-T a5ad521e u_ts_height 11
+T a5ad521e u_tershadow_aux 11
+T a5ad521e u_ts_height 12
 P 9068df1c skin.vert outline.frag #define OUTLINE;
 B 9068df1c vert 0 3348
 U 9068df1c vert u_model 0 mat4 1 0
@@ -2823,7 +2916,8 @@ T 9068df1c u_irradiance 4
 T 9068df1c u_prefilter 5
 T 9068df1c u_shadow 6
 T 9068df1c u_tershadow 7
-T 9068df1c u_ts_height 8
+T 9068df1c u_tershadow_aux 8
+T 9068df1c u_ts_height 9
 P e9b6300c skin.vert outline.frag #define OUTLINE;#define ALPHA_TEST;
 B e9b6300c vert 0 3348
 U e9b6300c vert u_model 0 mat4 1 0
@@ -2882,7 +2976,8 @@ T e9b6300c u_irradiance 4
 T e9b6300c u_prefilter 5
 T e9b6300c u_shadow 6
 T e9b6300c u_tershadow 7
-T e9b6300c u_ts_height 8
+T e9b6300c u_tershadow_aux 8
+T e9b6300c u_ts_height 9
 P b79a1f4e skin.vert shadow.frag #define SHADOW_PASS;
 B b79a1f4e vert 0 3344
 U b79a1f4e vert u_model 0 mat4 1 0
@@ -2939,7 +3034,8 @@ T b79a1f4e u_irradiance 4
 T b79a1f4e u_prefilter 5
 T b79a1f4e u_shadow 6
 T b79a1f4e u_tershadow 7
-T b79a1f4e u_ts_height 8
+T b79a1f4e u_tershadow_aux 8
+T b79a1f4e u_ts_height 9
 P a64015f2 skin.vert shadow.frag #define SHADOW_PASS;#define ALPHA_TEST;
 B a64015f2 vert 0 3344
 U a64015f2 vert u_model 0 mat4 1 0
@@ -2996,7 +3092,8 @@ T a64015f2 u_irradiance 4
 T a64015f2 u_prefilter 5
 T a64015f2 u_shadow 6
 T a64015f2 u_tershadow 7
-T a64015f2 u_ts_height 8
+T a64015f2 u_tershadow_aux 8
+T a64015f2 u_ts_height 9
 P 2e2908c8 terrain.vert terrain.frag 
 B 2e2908c8 vert 0 204
 U 2e2908c8 vert u_half 0 float 1 0
@@ -3075,7 +3172,8 @@ T 2e2908c8 u_snow_d 15
 T 2e2908c8 u_sunshadow 16
 T 2e2908c8 u_ter_normal 17
 T 2e2908c8 u_tershadow 18
-T 2e2908c8 u_ts_height 19
+T 2e2908c8 u_tershadow_aux 19
+T 2e2908c8 u_ts_height 20
 P 1f95f31b terrain.vert terrain.frag #define FAR_ONLY;
 B 1f95f31b vert 0 204
 U 1f95f31b vert u_half 0 float 1 0
@@ -3154,7 +3252,8 @@ T 1f95f31b u_snow_d 15
 T 1f95f31b u_sunshadow 16
 T 1f95f31b u_ter_normal 17
 T 1f95f31b u_tershadow 18
-T 1f95f31b u_ts_height 19
+T 1f95f31b u_tershadow_aux 19
+T 1f95f31b u_ts_height 20
 P f4382918 terrain.vert terrain.frag #define NEAR_ONLY;
 B f4382918 vert 0 204
 U f4382918 vert u_half 0 float 1 0
@@ -3233,7 +3332,8 @@ T f4382918 u_snow_d 15
 T f4382918 u_sunshadow 16
 T f4382918 u_ter_normal 17
 T f4382918 u_tershadow 18
-T f4382918 u_ts_height 19
+T f4382918 u_tershadow_aux 19
+T f4382918 u_ts_height 20
 P f2952361 terrain.vert terrain.frag #define SUN_INLINE;
 B f2952361 vert 0 204
 U f2952361 vert u_half 0 float 1 0
@@ -3312,7 +3412,8 @@ T f2952361 u_snow_d 15
 T f2952361 u_sunshadow 16
 T f2952361 u_ter_normal 17
 T f2952361 u_tershadow 18
-T f2952361 u_ts_height 19
+T f2952361 u_tershadow_aux 19
+T f2952361 u_ts_height 20
 P a0f2dbac terrain.vert terrain.frag #define SUN_INLINE;#define FAR_ONLY;
 B a0f2dbac vert 0 204
 U a0f2dbac vert u_half 0 float 1 0
@@ -3391,7 +3492,8 @@ T a0f2dbac u_snow_d 15
 T a0f2dbac u_sunshadow 16
 T a0f2dbac u_ter_normal 17
 T a0f2dbac u_tershadow 18
-T a0f2dbac u_ts_height 19
+T a0f2dbac u_tershadow_aux 19
+T a0f2dbac u_ts_height 20
 P 5e4589a1 terrain.vert terrain.frag #define SUN_INLINE;#define NEAR_ONLY;
 B 5e4589a1 vert 0 204
 U 5e4589a1 vert u_half 0 float 1 0
@@ -3470,7 +3572,8 @@ T 5e4589a1 u_snow_d 15
 T 5e4589a1 u_sunshadow 16
 T 5e4589a1 u_ter_normal 17
 T 5e4589a1 u_tershadow 18
-T 5e4589a1 u_ts_height 19
+T 5e4589a1 u_tershadow_aux 19
+T 5e4589a1 u_ts_height 20
 P bf3151c8 terrain.vert tersun.frag 
 B bf3151c8 vert 0 204
 U bf3151c8 vert u_half 0 float 1 0
@@ -3529,7 +3632,8 @@ T bf3151c8 u_prefilter 5
 T bf3151c8 u_shadow 6
 T bf3151c8 u_ter_normal 7
 T bf3151c8 u_tershadow 8
-T bf3151c8 u_ts_height 9
+T bf3151c8 u_tershadow_aux 9
+T bf3151c8 u_ts_height 10
 P 46e2325c water.vert water.frag 
 B 46e2325c vert 0 152
 U 46e2325c vert u_view 0 mat4 1 0
@@ -3591,7 +3695,8 @@ T 46e2325c u_refl 6
 T 46e2325c u_scene 7
 T 46e2325c u_shadow 8
 T 46e2325c u_tershadow 9
-T 46e2325c u_ts_height 10
+T 46e2325c u_tershadow_aux 10
+T 46e2325c u_ts_height 11
 P b20fdcb5 grass_inst.vert model.frag #define FOLIAGE;#define BLADE;#define GBLADE;#define GINST;
 B b20fdcb5 vert 0 160
 U b20fdcb5 vert u_view 0 mat4 1 0
@@ -3661,4 +3766,5 @@ T b20fdcb5 u_nrm 7
 T b20fdcb5 u_prefilter 8
 T b20fdcb5 u_shadow 9
 T b20fdcb5 u_tershadow 10
-T b20fdcb5 u_ts_height 11
+T b20fdcb5 u_tershadow_aux 11
+T b20fdcb5 u_ts_height 12

packages/ludic.render3d/shaders/tershadow.frag

@@ -10,7 +10,7 @@
 // The second channel is the distance to the occluder that set the bound, which widens
 // the penumbra the way a real shadow softens with distance from its caster.
 in vec2 v_uv;
-out vec4 o;
+out vec4 o;   // TS_AUX: the occluder distance and the cloud mask (RG16F); else the lowest lit height (R32F)
 uniform sampler2D u_height;
 uniform float u_half;
 uniform vec3 u_sun;
@@ -31,9 +31,13 @@ void main() {
       step *= 1.045;
     }
   }
-  // the cloud layer's mask, once, into B: sampled by cloudShadow() with the sun offset and
+  // the cloud layer's mask, once, into the aux target's G: sampled by cloudShadow() with the sun offset and
   // the drift applied as a uv shift, instead of a five-octave fbm in every lit pixel of
   // every pass
   float cloud = smoothstep(0.02, 0.32, fbm(xz * 0.0011, 5));
-  o = vec4(lit, at, cloud, 1.0);
+#ifdef TS_AUX
+  o = vec4(at, cloud, 0.0, 1.0);
+#else
+  o = vec4(lit, 0.0, 0.0, 1.0);
+#endif
 }

packages/ludic.render3d/shaders/variants.list

@@ -16,6 +16,7 @@ fullscreen.vert|ssao_blur.frag|
 fullscreen.vert|ssgi.frag|
 fullscreen.vert|ternormal.frag|
 fullscreen.vert|tershadow.frag|#define NOISE_ONLY;
+fullscreen.vert|tershadow.frag|#define NOISE_ONLY;#define TS_AUX;
 fullscreen.vert|tonemap.frag|
 fullscreen.vert|tonemap.frag|#define HDR10;
 fullscreen.vert|volumetric.frag|

packages/ludic.render3d/shadow.ludic

@@ -239,9 +239,11 @@ function shadow_bind(render3d_st: mut Render3dState, prog: int) -> void {
   r3d_bind_tex(render3d_st, prog, "u_shadow", 15, GPU_TEX2D_ARRAY, render3d_st.sh_tex)
   # the height-field shadow (terrain.ludic); a stand-in texture keeps the unit valid before the bake
   var ts = render3d_st.ter_shadow_tex
+  var ta = render3d_st.ter_shadow_aux
   var ts_on = 1.0
-  if ts == 0 { ts = render3d_st.ter_height_tex;  ts_on = 0.0 }
+  if ts == 0 or ta == 0 { ts = render3d_st.ter_height_tex;  ta = render3d_st.ter_height_tex;  ts_on = 0.0 }
   r3d_bind_2d(render3d_st, prog, "u_tershadow", 6, ts)
+  r3d_bind_2d(render3d_st, prog, "u_tershadow_aux", 7, ta)
   terrain_bind_height(render3d_st, prog)
   u_f(render3d_st, gpu_uniform(render3d_st, prog, "u_ts_on"), ts_on)
   u_f(render3d_st, gpu_uniform(render3d_st, prog, "u_ts_half"), float(render3d_st.TERRAIN_HALF))

packages/ludic.render3d/terrain.ludic

@@ -242,6 +242,9 @@ function terrain_generate__t(render3d_st: mut Render3dState) -> void {
   gpu_fb_bind(render3d_st, 0)
   gpu_fb_free(render3d_st, fbo)
   gpu_program_free(render3d_st, p)
+  # the survey is read only here: kept, it was 44 MB (R16 with mips) for the life of the map. A
+  # world swap loads its own again (terrain_reload), and nothing else generates
+  if render3d_st.ter_dem_tex != 0 { gpu_tex_free(render3d_st, render3d_st.ter_dem_tex);  render3d_st.ter_dem_tex = 0 }
   gpu_check(render3d_st, "terrain generate")
 }
 
@@ -257,12 +260,26 @@ function terrain_bind_height(render3d_st: mut Render3dState, p: int) -> void {
 # the sun moves; r3d_frame calls it again when sky_set_yaw has changed the yaw.
 function terrain_bake_shadow(render3d_st: mut Render3dState) -> void {
   if render3d_st.sun_dir == null { return }
-  if render3d_st.ter_shadow_tex == 0 { render3d_st.ter_shadow_tex = tex_target(render3d_st, TERRAIN_SHADOW_RES, TERRAIN_SHADOW_RES, GL_RGBA32F, GL_RGBA, GL_FLOAT, GL_LINEAR) }
+  # the lowest lit height needs 32 bits (a receiver 3000 m up compares against it to a quarter metre);
+  # the occluder's distance and the cloud mask do not, and go beside it in RG16F - 32 MB where one
+  # RGBA32F carrying all three (and an unused fourth) was 64
+  if render3d_st.ter_shadow_tex == 0 { render3d_st.ter_shadow_tex = tex_target(render3d_st, TERRAIN_SHADOW_RES, TERRAIN_SHADOW_RES, GL_R32F, GL_RED, GL_FLOAT, GL_LINEAR) }
+  if render3d_st.ter_shadow_aux == 0 { render3d_st.ter_shadow_aux = tex_target(render3d_st, TERRAIN_SHADOW_RES, TERRAIN_SHADOW_RES, GL_RG16F, GL_RG, GL_FLOAT, GL_LINEAR) }
   if render3d_st.ter_shadow_prog == 0 { render3d_st.ter_shadow_prog = r3d_program(render3d_st, "fullscreen.vert", "tershadow.frag", "#define NOISE_ONLY\n") }
-  let p = render3d_st.ter_shadow_prog
+  if render3d_st.ter_shadow_prog_aux == 0 { render3d_st.ter_shadow_prog_aux = r3d_program(render3d_st, "fullscreen.vert", "tershadow.frag", "#define NOISE_ONLY\n#define TS_AUX\n") }
+  # two passes, one target each: a pipeline takes one colour format for all its targets, and the two
+  # are R32F and RG16F (drawn together, the second's writes went nowhere and nothing was lit)
+  terrain_bake_pass(render3d_st, render3d_st.ter_shadow_prog, render3d_st.ter_shadow_tex)
+  terrain_bake_pass(render3d_st, render3d_st.ter_shadow_prog_aux, render3d_st.ter_shadow_aux)
+  render3d_st.ter_shadow_yaw = render3d_st.sky_yaw
+  gpu_check(render3d_st, "terrain shadow bake")
+}
+
+# one of the bake's two targets drawn: the march is the same, the define picks what it writes
+function terrain_bake_pass(render3d_st: mut Render3dState, p: int, target: int) -> void {
   let fbo = gpu_fb_new(render3d_st)
   gpu_fb_bind(render3d_st, fbo)
-  gpu_fb_color(render3d_st, 0, render3d_st.ter_shadow_tex)
+  gpu_fb_color(render3d_st, 0, target)
   gpu_viewport(render3d_st, 0, 0, TERRAIN_SHADOW_RES, TERRAIN_SHADOW_RES)
   gpu_depth_test(render3d_st, false)
   gpu_blend(render3d_st, false)
@@ -274,8 +291,6 @@ function terrain_bake_shadow(render3d_st: mut Render3dState) -> void {
   mesh_draw(render3d_st, render3d_st.sky_fullscreen)
   gpu_fb_bind(render3d_st, 0)
   gpu_fb_free(render3d_st, fbo)
-  render3d_st.ter_shadow_yaw = render3d_st.sky_yaw
-  gpu_check(render3d_st, "terrain shadow bake")
 }
 
 # height at world (x, z) — float bits, bilinear over the CPU copy