From 85926061d5b51a452a70a5c2675a5eb58ef854ce Mon Sep 17 00:00:00 2001 From: andrewjhaman Date: Sun, 9 Jul 2023 21:14:59 -0400 Subject: [PATCH] Fit Shadows to Frustum --- main.c | 153 ++++++++++++++++++++++++++++++++++++-------------- threedee.glsl | 2 +- tuning.h | 2 +- 3 files changed, 112 insertions(+), 45 deletions(-) diff --git a/main.c b/main.c index 3051b0c..04b35fd 100644 --- a/main.c +++ b/main.c @@ -4989,7 +4989,45 @@ float round_to_nearest(float input, float round_target) return result; } -Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir) + +typedef struct +{ + //For now we consider all vertices on the near plane to be equal to the camera position, and store that at vertices[0]; + Vec3 vertices[5]; +} FrustumVertices; + +FrustumVertices get_frustum_vertices(Vec3 cam_pos, Vec3 cam_forward, Vec3 cam_right) { + FrustumVertices result = {0}; + + float aspect_ratio = (float)sapp_width() / (float)sapp_height(); + + const int num_frustum_vertices = sizeof(result.vertices)/sizeof(result.vertices[0]); + + const float cascade_distance = FAR_PLANE_DISTANCE; + + Vec2 far_plane_half_dims; + far_plane_half_dims.y = cascade_distance * tanf(FIELD_OF_VIEW * 0.5f); + far_plane_half_dims.x = far_plane_half_dims.y * aspect_ratio; + + Vec3 cam_up = Cross(cam_right, cam_forward); + + Vec3 far_plane_centre = AddV3(cam_pos, MulV3F(cam_forward, cascade_distance)); + Vec3 far_plane_offset_to_right_side = MulV3F(cam_right, far_plane_half_dims.x); + Vec3 far_plane_offset_to_top_side = MulV3F(cam_up , far_plane_half_dims.y); + Vec3 far_plane_offset_to_left_side = MulV3F(far_plane_offset_to_right_side, -1.0); + Vec3 far_plane_offset_to_bot_side = MulV3F(far_plane_offset_to_top_side , -1.0); + + result.vertices[0] = cam_pos; + result.vertices[1] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_bot_side, far_plane_offset_to_left_side )); + result.vertices[2] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_bot_side, far_plane_offset_to_right_side)); + result.vertices[3] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_top_side, far_plane_offset_to_right_side)); + result.vertices[4] = AddV3(far_plane_centre, AddV3(far_plane_offset_to_top_side, far_plane_offset_to_left_side )); + + + return result; +} + +Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir, Vec3 cam_pos, Vec3 cam_forward, Vec3 cam_right) { Shadow_Volume_Params result = {0}; @@ -5002,55 +5040,34 @@ Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir) //To make up for this, we add an extra padding-skirt to the bounds. Mat4 light_space_matrix = LookAt_RH((Vec3){0}, light_dir, V3(0, 1, 0)); - Vec3 scene_min = V3( INFINITY, INFINITY, INFINITY); - Vec3 scene_max = V3(-INFINITY, -INFINITY, -INFINITY); + Vec3 frustum_min = V3( INFINITY, INFINITY, INFINITY); + Vec3 frustum_max = V3(-INFINITY, -INFINITY, -INFINITY); - for(PlacedMesh *cur = level_threedee.placed_mesh_list; cur; cur = cur->next) - { - Vec3 p = MulM4V3(light_space_matrix, cur->t.offset); + FrustumVertices frustum_vertices_worldspace = get_frustum_vertices(cam_pos, cam_forward, cam_right); + const int num_frustum_vertices = sizeof(frustum_vertices_worldspace.vertices)/sizeof(frustum_vertices_worldspace.vertices[0]); - scene_min.x = fminf(scene_min.x, p.x); - scene_max.x = fmaxf(scene_max.x, p.x); + for (int i = 0; i < num_frustum_vertices; ++i) { + Vec3 p = frustum_vertices_worldspace.vertices[i]; - scene_min.y = fminf(scene_min.y, p.y); - scene_max.y = fmaxf(scene_max.y, p.y); - - scene_min.z = fminf(scene_min.z, p.z); - scene_max.z = fmaxf(scene_max.z, p.z); - } + p = MulM4V3(light_space_matrix, p); - ENTITIES_ITER(gs.entities) - { - if(it->is_npc || it->is_character) - { - Transform draw_with = entity_transform(it); - Vec3 p = MulM4V3(light_space_matrix, draw_with.offset); + frustum_min.x = fminf(frustum_min.x, p.x); + frustum_max.x = fmaxf(frustum_max.x, p.x); - scene_min.x = fminf(scene_min.x, p.x); - scene_max.x = fmaxf(scene_max.x, p.x); - - scene_min.y = fminf(scene_min.y, p.y); - scene_max.y = fmaxf(scene_max.y, p.y); - - scene_min.z = fminf(scene_min.z, p.z); - scene_max.z = fmaxf(scene_max.z, p.z); - } + frustum_min.y = fminf(frustum_min.y, p.y); + frustum_max.y = fmaxf(frustum_max.y, p.y); + + frustum_min.z = fminf(frustum_min.z, p.z); + frustum_max.z = fmaxf(frustum_max.z, p.z); } - //pad to account for entity width - float pad = 2.5f; - - scene_min.x -= pad; - scene_min.y -= pad; - scene_max.x += pad; - scene_max.y += pad; - result.l = scene_min.x; - result.r = scene_max.x; + result.l = frustum_min.x; + result.r = frustum_max.x; - result.b = scene_min.y; - result.t = scene_max.y; + result.b = frustum_min.y; + result.t = frustum_max.y; float w = result.r - result.l; float h = result.t - result.b; @@ -5087,6 +5104,54 @@ Shadow_Volume_Params calculate_shadow_volume_params(Vec3 light_dir) return result; } + +void debug_draw_img(sg_image img, int index) { + draw_quad((DrawParams){quad_at(V2(512.0f*index, 512.0), V2(512.0, 512.0)), IMG(state.shadows.color_img), WHITE, .layer=LAYER_UI}); +} + +void debug_draw_img_with_border(sg_image img, int index) { + float bs = 50.0; + draw_quad((DrawParams){quad_at(V2(512.0f*index, 512.0), V2(512.0, 512.0)), state.shadows.color_img, (AABB){V2(-bs, -bs), AddV2(img_size(img), V2(bs, bs))}, WHITE, .layer=LAYER_UI}); +} + +void debug_draw_shadow_info(Vec3 frustum_tip, Vec3 cam_forward, Vec3 cam_right, Mat4 light_space_matrix) { + debug_draw_img(state.shadows.color_img, 0); + FrustumVertices fv = get_frustum_vertices(frustum_tip, cam_forward, cam_right); + + Vec2 projs[5]; + for (int i = 0; i < 5; ++i) { + Vec3 v = fv.vertices[i]; + Vec4 p = V4(v.x, v.y, v.z, 1.0); + Vec4 proj = MulM4V4(light_space_matrix, p); + proj.x /= proj.w; + proj.y /= proj.w; + proj.z /= proj.w; + + proj.x *= 0.5f; + proj.x += 0.5f; + proj.y *= 0.5f; + proj.y += 0.5f; + proj.z *= 0.5f; + proj.z += 0.5f; + + proj.x *= 512.0f; + proj.y *= 512.0f; + + projs[i] = proj.XY; + dbgsquare(proj.XY); + } + + dbgline(projs[0], projs[1]); + dbgline(projs[0], projs[2]); + dbgline(projs[0], projs[3]); + dbgline(projs[0], projs[4]); + dbgline(projs[1], projs[2]); + dbgline(projs[2], projs[3]); + dbgline(projs[3], projs[4]); + dbgline(projs[4], projs[1]); +} + + void actually_draw_thing(DrawnThing *it, Mat4 light_space_matrix, bool for_outline) { if(it->mesh) @@ -5163,7 +5228,7 @@ void actually_draw_thing(DrawnThing *it, Mat4 light_space_matrix, bool for_outli // I moved this out into its own separate function so that you could // define helper functions to be used multiple times in it, and those functions // would be near the actual 3d drawing in the file -void flush_all_drawn_things(Vec3 light_dir) +void flush_all_drawn_things(Vec3 light_dir, Vec3 cam_pos, Vec3 cam_facing, Vec3 cam_right) { // Draw all the 3D drawn things. Draw the shadows, then draw the things with the shadows. // Process armatures and upload their skeleton textures @@ -5247,10 +5312,12 @@ void flush_all_drawn_things(Vec3 light_dir) // do the shadow pass Mat4 light_space_matrix; { - Shadow_Volume_Params svp = calculate_shadow_volume_params(light_dir); + Shadow_Volume_Params svp = calculate_shadow_volume_params(light_dir, cam_pos, cam_facing, cam_right); + Mat4 shadow_view = LookAt_RH(V3(0, 0, 0), light_dir, V3(0, 1, 0)); Mat4 shadow_projection = Orthographic_RH_NO(svp.l, svp.r, svp.b, svp.t, svp.n, svp.f); light_space_matrix = MulM4(shadow_projection, shadow_view); + // debug_draw_shadow_info(cam_pos, cam_facing, cam_right, light_space_matrix); sg_begin_pass(state.shadows.pass, &state.shadows.pass_action); @@ -5544,7 +5611,7 @@ void frame(void) } - flush_all_drawn_things(light_dir); + flush_all_drawn_things(light_dir, cam_pos, facing, right); // draw the freaking outline. Play ball! draw_quad((DrawParams){quad_at(V2(0.0, screen_size().y), screen_size()), IMG(state.outline_pass_image), WHITE, .layer = LAYER_UI_FG, .custom_pipeline = state.twodee_outline_pip}); diff --git a/threedee.glsl b/threedee.glsl index 68f1099..f2dfbeb 100644 --- a/threedee.glsl +++ b/threedee.glsl @@ -147,7 +147,7 @@ float do_shadow_sample(sampler2D shadowMap, vec2 uv, float scene_depth, float n_ float offset_scale_N = sqrt(1 - n_dot_l*n_dot_l); float offset_scale_L = offset_scale_N / n_dot_l; - float bias = 0.0002 * offset_scale_N + 0.0001 * offset_scale_L; + float bias = 0.0004 * offset_scale_N + 0.0001 * offset_scale_L; map_depth += bias; diff --git a/tuning.h b/tuning.h index d919521..796c78e 100644 --- a/tuning.h +++ b/tuning.h @@ -59,5 +59,5 @@ //Rendering #define FIELD_OF_VIEW (PI32/4.0f) #define NEAR_PLANE_DISTANCE (0.01f) -#define FAR_PLANE_DISTANCE (1000.0f) +#define FAR_PLANE_DISTANCE (45.0f) #define SHADOW_MAP_DIMENSION (2048)