Eevee: Shadows: Separate Cube and Cascade shadow maps into 2 texture array.

This mean we can now have different shadow resolutions for both.

However each shadow type keep the same size accross all lamps because of
future "real" Cube Shadowmaps limitation and to save texture sampler slots.

That said the cascade shadow resolution could (in the future) still be
changed to be adjustable per sun lamp.

1 files changed, 72 insertions, 45 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_lights.c b/source/blender/draw/engines/eevee/eevee_lights.c
index b7adcbf0835..b7790d7dd0f 100644
--- a/source/blender/draw/engines/eevee/eevee_lights.c
+++ b/source/blender/draw/engines/eevee/eevee_lights.c
@@ -129,30 +129,24 @@ void EEVEE_lights_init(EEVEE_ViewLayerData *sldata)
 	SWAP(EEVEE_ShadowCasterBuffer *, sldata->lamps->shcaster_frontbuffer, sldata->lamps->shcaster_backbuffer);
 
 	int sh_method = BKE_collection_engine_property_value_get_int(props, "shadow_method");
-	int sh_size = BKE_collection_engine_property_value_get_int(props, "shadow_size");
+	int sh_cube_size = BKE_collection_engine_property_value_get_int(props, "shadow_cube_size");
+	int sh_cascade_size = BKE_collection_engine_property_value_get_int(props, "shadow_cascade_size");
 	int sh_high_bitdepth = BKE_collection_engine_property_value_get_int(props, "shadow_high_bitdepth");
 
 	EEVEE_LampsInfo *linfo = sldata->lamps;
-	if ((linfo->shadow_size != sh_size) ||
+	if ((linfo->shadow_cube_size != sh_cube_size) ||
 	    (linfo->shadow_method != sh_method) ||
 	    (linfo->shadow_high_bitdepth != sh_high_bitdepth))
 	{
-		BLI_assert((sh_size > 0) && (sh_size <= 8192));
-		DRW_TEXTURE_FREE_SAFE(sldata->shadow_pool);
+		BLI_assert((sh_cube_size > 0) && (sh_cube_size <= 8192));
+		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cube_pool);
 		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cube_target);
-		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cascade_target);
 		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cube_blur);
-		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cascade_blur);
-
-		linfo->shadow_high_bitdepth = sh_high_bitdepth;
-		linfo->shadow_method = sh_method;
-		linfo->shadow_size = sh_size;
-		linfo->shadow_render_data.stored_texel_size = 1.0 / (float)linfo->shadow_size;
 
 		/* Compute adequate size for the cubemap render target.
 		 * The 3.0f factor is here to make sure there is no under sampling between
 		 * the octahedron mapping and the cubemap. */
-		int new_cube_target_size = (int)ceil(sqrt((float)(sh_size * sh_size) / 6.0f) * 3.0f);
+		int new_cube_target_size = (int)ceil(sqrt((float)(sh_cube_size * sh_cube_size) / 6.0f) * 3.0f);
 
 		CLAMP(new_cube_target_size, 1, 4096);
 
@@ -160,6 +154,21 @@ void EEVEE_lights_init(EEVEE_ViewLayerData *sldata)
 		linfo->shadow_render_data.cube_texel_size = 1.0 / (float)linfo->shadow_cube_target_size;
 	}
 
+	if ((linfo->shadow_cascade_size != sh_cascade_size) ||
+	    (linfo->shadow_method != sh_method) ||
+	    (linfo->shadow_high_bitdepth != sh_high_bitdepth))
+	{
+		BLI_assert((sh_cascade_size > 0) && (sh_cascade_size <= 8192));
+		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cascade_pool);
+		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cascade_target);
+		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cascade_blur);
+	}
+
+	linfo->shadow_high_bitdepth = sh_high_bitdepth;
+	linfo->shadow_method = sh_method;
+	linfo->shadow_cube_size = sh_cube_size;
+	linfo->shadow_cascade_size = sh_cascade_size;
+
 	/* only compile the ones needed. reduce startup time. */
 	if ((sh_method == SHADOW_ESM) && !e_data.shadow_store_cube_sh[SHADOW_ESM]) {
 		DynStr *ds_frag = BLI_dynstr_new();
@@ -223,7 +232,8 @@ void EEVEE_lights_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 
 	linfo->shcaster_frontbuffer->count = 0;
 	linfo->num_light = 0;
-	linfo->num_layer = 0;
+	linfo->num_cube_layer = 0;
+	linfo->num_cascade_layer = 0;
 	linfo->gpu_cube_ct = linfo->gpu_cascade_ct = linfo->gpu_shadow_ct = 0;
 	linfo->cpu_cube_ct = linfo->cpu_cascade_ct = 0;
 	memset(linfo->light_ref, 0, sizeof(linfo->light_ref));
@@ -331,12 +341,12 @@ void EEVEE_lights_cache_add(EEVEE_ViewLayerData *sldata, Object *ob)
 					EEVEE_ShadowCascadeData *data = &led->data.scad;
 					data->shadow_id = linfo->gpu_shadow_ct;
 					data->cascade_id = linfo->gpu_cascade_ct;
-					data->layer_id = linfo->num_layer;
+					data->layer_id = linfo->num_cascade_layer;
 
 					/* Increment indices. */
 					linfo->gpu_shadow_ct += 1;
 					linfo->gpu_cascade_ct += sh_nbr;
-					linfo->num_layer += sh_nbr * cascade_nbr;
+					linfo->num_cascade_layer += sh_nbr * cascade_nbr;
 
 					linfo->cpu_cascade_ct += 1;
 				}
@@ -365,12 +375,12 @@ void EEVEE_lights_cache_add(EEVEE_ViewLayerData *sldata, Object *ob)
 					/* Store indices. */
 					data->shadow_id = linfo->gpu_shadow_ct;
 					data->cube_id = linfo->gpu_cube_ct;
-					data->layer_id = linfo->num_layer;
+					data->layer_id = linfo->num_cube_layer;
 
 					/* Increment indices. */
 					linfo->gpu_shadow_ct += 1;
 					linfo->gpu_cube_ct += sh_nbr;
-					linfo->num_layer += sh_nbr;
+					linfo->num_cube_layer += sh_nbr;
 
 					linfo->cpu_cube_ct += 1;
 				}
@@ -478,9 +488,15 @@ void EEVEE_lights_cache_finish(EEVEE_ViewLayerData *sldata)
 
 	/* Setup enough layers. */
 	/* Free textures if number mismatch. */
-	if (linfo->num_layer != linfo->cache_num_layer) {
-		DRW_TEXTURE_FREE_SAFE(sldata->shadow_pool);
-		linfo->cache_num_layer = linfo->num_layer;
+	if (linfo->num_cube_layer != linfo->cache_num_cube_layer) {
+		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cube_pool);
+		linfo->cache_num_cube_layer = linfo->num_cube_layer;
+		linfo->update_flag |= LIGHT_UPDATE_SHADOW_CUBE;
+	}
+
+	if (linfo->num_cube_layer != linfo->cache_num_cube_layer) {
+		DRW_TEXTURE_FREE_SAFE(sldata->shadow_cube_pool);
+		linfo->cache_num_cube_layer = linfo->num_cube_layer;
 		linfo->update_flag |= LIGHT_UPDATE_SHADOW_CUBE;
 	}
 
@@ -492,27 +508,29 @@ void EEVEE_lights_cache_finish(EEVEE_ViewLayerData *sldata)
 			break;
 	}
 
+	/* Cubemaps */
 	if (!sldata->shadow_cube_target) {
-		/* TODO render everything on the same 2d render target using clip planes and no Geom Shader. */
-		/* Cubemaps */
 		sldata->shadow_cube_target = DRW_texture_create_cube(
 		        linfo->shadow_cube_target_size, GPU_DEPTH_COMPONENT24, 0, NULL);
 		sldata->shadow_cube_blur = DRW_texture_create_cube(
 		        linfo->shadow_cube_target_size, shadow_pool_format, DRW_TEX_FILTER, NULL);
 	}
+	if (!sldata->shadow_cube_pool) {
+		sldata->shadow_cube_pool = DRW_texture_create_2D_array(
+		        linfo->shadow_cube_size, linfo->shadow_cube_size, max_ff(1, linfo->num_cube_layer),
+		        shadow_pool_format, DRW_TEX_FILTER, NULL);
+	}
 
+	/* CSM */
 	if (!sldata->shadow_cascade_target) {
-		/* CSM */
 		sldata->shadow_cascade_target = DRW_texture_create_2D_array(
-		        linfo->shadow_size, linfo->shadow_size, MAX_CASCADE_NUM, GPU_DEPTH_COMPONENT24, 0, NULL);
+		        linfo->shadow_cascade_size, linfo->shadow_cascade_size, MAX_CASCADE_NUM, GPU_DEPTH_COMPONENT24, 0, NULL);
 		sldata->shadow_cascade_blur = DRW_texture_create_2D_array(
-		        linfo->shadow_size, linfo->shadow_size, MAX_CASCADE_NUM, shadow_pool_format, DRW_TEX_FILTER, NULL);
+		        linfo->shadow_cascade_size, linfo->shadow_cascade_size, MAX_CASCADE_NUM, shadow_pool_format, DRW_TEX_FILTER, NULL);
 	}
-
-	if (!sldata->shadow_pool) {
-		/* All shadows fit in this array */
-		sldata->shadow_pool = DRW_texture_create_2D_array(
-		        linfo->shadow_size, linfo->shadow_size, max_ff(1, linfo->num_layer),
+	if (!sldata->shadow_cascade_pool) {
+		sldata->shadow_cascade_pool = DRW_texture_create_2D_array(
+		        linfo->shadow_cascade_size, linfo->shadow_cascade_size, max_ff(1, linfo->num_cascade_layer),
 		        shadow_pool_format, DRW_TEX_FILTER, NULL);
 	}
 
@@ -525,9 +543,14 @@ void EEVEE_lights_cache_finish(EEVEE_ViewLayerData *sldata)
 	});
 
 	/* Storage FB */
-	GPU_framebuffer_ensure_config(&sldata->shadow_store_fb, {
+	GPU_framebuffer_ensure_config(&sldata->shadow_cube_store_fb, {
 		GPU_ATTACHMENT_NONE,
-		GPU_ATTACHMENT_TEXTURE(sldata->shadow_pool)
+		GPU_ATTACHMENT_TEXTURE(sldata->shadow_cube_pool)
+	});
+
+	GPU_framebuffer_ensure_config(&sldata->shadow_cascade_store_fb, {
+		GPU_ATTACHMENT_NONE,
+		GPU_ATTACHMENT_TEXTURE(sldata->shadow_cascade_pool)
 	});
 
 	/* Update Lamps UBOs. */
@@ -860,7 +883,7 @@ static void eevee_shadow_cascade_setup(Object *ob, EEVEE_LampsInfo *linfo, EEVEE
 		/* Snap projection center to nearest texel to cancel shimmering. */
 		float shadow_origin[2], shadow_texco[2];
 		/* Light to texture space. */
-		mul_v2_v2fl(shadow_origin, center, linfo->shadow_size / (2.0f * sh_data->radius[c]));
+		mul_v2_v2fl(shadow_origin, center, linfo->shadow_cascade_size / (2.0f * sh_data->radius[c]));
 
 		/* Find the nearest texel. */
 		shadow_texco[0] = roundf(shadow_origin[0]);
@@ -868,7 +891,7 @@ static void eevee_shadow_cascade_setup(Object *ob, EEVEE_LampsInfo *linfo, EEVEE
 
 		/* Compute offset. */
 		sub_v2_v2(shadow_texco, shadow_origin);
-		mul_v2_fl(shadow_texco, (2.0f * sh_data->radius[c]) / linfo->shadow_size); /* Texture to light space. */
+		mul_v2_fl(shadow_texco, (2.0f * sh_data->radius[c]) / linfo->shadow_cascade_size); /* Texture to light space. */
 
 		/* Apply offset. */
 		add_v2_v2(center, shadow_texco);
@@ -1045,6 +1068,8 @@ void EEVEE_draw_shadows(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl)
 		srd->clip_far = la->clipend;
 		copy_v3_v3(srd->position, ob->obmat[3]);
 
+		srd->stored_texel_size = 1.0 / (float)linfo->shadow_cube_size;
+
 		DRW_uniformbuffer_update(sldata->shadow_render_ubo, srd);
 
 		/* Render shadow cube */
@@ -1082,9 +1107,9 @@ void EEVEE_draw_shadows(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl)
 		     linfo->current_shadow_face++)
 		{
 			/* Copy using a small 3x3 box filter */
-			GPU_framebuffer_texture_cubeface_attach(sldata->shadow_store_fb, sldata->shadow_cube_blur, 0,
+			GPU_framebuffer_texture_cubeface_attach(sldata->shadow_cube_store_fb, sldata->shadow_cube_blur, 0,
 			                                        linfo->current_shadow_face, 0);
-			GPU_framebuffer_bind(sldata->shadow_store_fb);
+			GPU_framebuffer_bind(sldata->shadow_cube_store_fb);
 			DRW_draw_pass(psl->shadow_cube_copy_pass);
 		}
 
@@ -1109,8 +1134,8 @@ void EEVEE_draw_shadows(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl)
 		srd->shadow_inv_samples_ct = 1.0f / (float)srd->shadow_samples_ct;
 		DRW_uniformbuffer_update(sldata->shadow_render_ubo, srd);
 
-		GPU_framebuffer_texture_layer_attach(sldata->shadow_store_fb, sldata->shadow_pool, 0, evscd->layer_id, 0);
-		GPU_framebuffer_bind(sldata->shadow_store_fb);
+		GPU_framebuffer_texture_layer_attach(sldata->shadow_cube_store_fb, sldata->shadow_cube_pool, 0, evscd->layer_id, 0);
+		GPU_framebuffer_bind(sldata->shadow_cube_store_fb);
 		DRW_draw_pass(psl->shadow_cube_store_pass);
 
 		led->need_update = false;
@@ -1142,6 +1167,7 @@ void EEVEE_draw_shadows(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl)
 
 		srd->clip_near = la->clipsta;
 		srd->clip_far = la->clipend;
+		srd->stored_texel_size = 1.0 / (float)linfo->shadow_cascade_size;
 
 		DRW_uniformbuffer_update(sldata->shadow_render_ubo, &linfo->shadow_render_data);
 
@@ -1174,13 +1200,14 @@ void EEVEE_draw_shadows(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl)
 		{
 			/* 0.01f factor to convert to percentage */
 			float filter_texture_size = la->soft * 0.01f / evscd->radius[linfo->current_shadow_cascade];
-			float filter_pixel_size = ceil(linfo->shadow_size * filter_texture_size);
+			float filter_pixel_size = ceil(linfo->shadow_cascade_size * filter_texture_size);
 
 			/* Copy using a small 3x3 box filter */
-			linfo->filter_size = linfo->shadow_render_data.stored_texel_size * ((filter_pixel_size > 1.0f) ? 1.0f : 0.0f);
+			/* NOTE: We always do it in the case of CSM because of artifacts in the farthest cascade. */
+			linfo->filter_size = srd->stored_texel_size;
 			GPU_framebuffer_texture_layer_attach(
-			        sldata->shadow_store_fb, sldata->shadow_cascade_blur, 0, linfo->current_shadow_cascade, 0);
-			GPU_framebuffer_bind(sldata->shadow_store_fb);
+			        sldata->shadow_cascade_store_fb, sldata->shadow_cascade_blur, 0, linfo->current_shadow_cascade, 0);
+			GPU_framebuffer_bind(sldata->shadow_cascade_store_fb);
 			DRW_draw_pass(psl->shadow_cascade_copy_pass);
 
 			/* Push it to shadowmap array and blur more */
@@ -1191,7 +1218,7 @@ void EEVEE_draw_shadows(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl)
 			const int max_sample = 256;
 
 			if (filter_pixel_size > 2.0f) {
-				linfo->filter_size = linfo->shadow_render_data.stored_texel_size * max_filter_size * previous_box_filter_size;
+				linfo->filter_size = srd->stored_texel_size * max_filter_size * previous_box_filter_size;
 				filter_pixel_size = max_ff(0.0f, filter_pixel_size - 3.0f);
 				/* Compute number of concentric samples. Depends directly on filter size. */
 				float pix_size_sqr = filter_pixel_size * filter_pixel_size;
@@ -1205,8 +1232,8 @@ void EEVEE_draw_shadows(EEVEE_ViewLayerData *sldata, EEVEE_PassList *psl)
 			DRW_uniformbuffer_update(sldata->shadow_render_ubo, &linfo->shadow_render_data);
 
 			int layer = evscd->layer_id + linfo->current_shadow_cascade;
-			GPU_framebuffer_texture_layer_attach(sldata->shadow_store_fb, sldata->shadow_pool, 0, layer, 0);
-			GPU_framebuffer_bind(sldata->shadow_store_fb);
+			GPU_framebuffer_texture_layer_attach(sldata->shadow_cascade_store_fb, sldata->shadow_cascade_pool, 0, layer, 0);
+			GPU_framebuffer_bind(sldata->shadow_cascade_store_fb);
 			DRW_draw_pass(psl->shadow_cascade_store_pass);
 		}
 	}