Eevee: Render: Add ambient occlusion pass support.

4 files changed, 107 insertions, 0 deletions

diff --git a/release/scripts/startup/bl_ui/properties_view_layer.py b/release/scripts/startup/bl_ui/properties_view_layer.py
index b58b034ca55..4d61aacbf22 100644
--- a/release/scripts/startup/bl_ui/properties_view_layer.py
+++ b/release/scripts/startup/bl_ui/properties_view_layer.py
@@ -469,6 +469,8 @@ class VIEWLAYER_PT_eevee_layer_passes(ViewLayerButtonsPanel, Panel):
         col.prop(view_layer, "use_pass_z")
         col.prop(view_layer, "use_pass_mist")
         col.prop(view_layer, "use_pass_normal")
+        col.separator()
+        col.prop(view_layer, "use_pass_ambient_occlusion")
 
         col = split.column()
         col.label(text="Subsurface:")
diff --git a/source/blender/draw/engines/eevee/eevee_occlusion.c b/source/blender/draw/engines/eevee/eevee_occlusion.c
index 9da438e825f..944003d7d1f 100644
--- a/source/blender/draw/engines/eevee/eevee_occlusion.c
+++ b/source/blender/draw/engines/eevee/eevee_occlusion.c
@@ -123,6 +123,48 @@ int EEVEE_occlusion_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 	return 0;
 }
 
+void EEVEE_occlusion_output_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
+{
+	EEVEE_FramebufferList *fbl = vedata->fbl;
+	EEVEE_TextureList *txl = vedata->txl;
+	EEVEE_PassList *psl = vedata->psl;
+	const float *viewport_size = DRW_viewport_size_get();
+
+	const DRWContextState *draw_ctx = DRW_context_state_get();
+	ViewLayer *view_layer = draw_ctx->view_layer;
+	IDProperty *props = BKE_view_layer_engine_evaluated_get(view_layer, COLLECTION_MODE_NONE, RE_engine_id_BLENDER_EEVEE);
+
+	if (BKE_collection_engine_property_value_get_bool(props, "gtao_enable")) {
+		DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
+		float clear[4] = {0.0f, 0.0f, 0.0f, 0.0f};
+
+		DRWFboTexture tex_data = {&txl->ao_accum, DRW_TEX_R_32, 0};
+		DRW_framebuffer_init(&fbl->ao_accum_fb, &draw_engine_eevee_type, (int)viewport_size[0], (int)viewport_size[1],
+		                     &tex_data, 1);
+
+		/* Clear texture. */
+		DRW_framebuffer_bind(fbl->ao_accum_fb);
+		DRW_framebuffer_clear(true, false, false, clear, 0.0f);
+
+		/* Accumulation pass */
+		DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_ADDITIVE;
+		psl->ao_accum_ps = DRW_pass_create("AO Accum", state);
+		DRWShadingGroup *grp = DRW_shgroup_create(e_data.gtao_debug_sh, psl->ao_accum_ps);
+		DRW_shgroup_uniform_texture(grp, "utilTex", EEVEE_materials_get_util_tex());
+		DRW_shgroup_uniform_buffer(grp, "maxzBuffer", &txl->maxzbuffer);
+		DRW_shgroup_uniform_buffer(grp, "depthBuffer", &dtxl->depth);
+		DRW_shgroup_uniform_buffer(grp, "normalBuffer", &txl->ssr_normal_input);
+		DRW_shgroup_uniform_buffer(grp, "horizonBuffer", &txl->gtao_horizons);
+		DRW_shgroup_uniform_block(grp, "common_block", sldata->common_ubo);
+		DRW_shgroup_call_add(grp, DRW_cache_fullscreen_quad_get(), NULL);
+	}
+	else {
+		/* Cleanup to release memory */
+		DRW_TEXTURE_FREE_SAFE(txl->ao_accum);
+		DRW_FRAMEBUFFER_FREE_SAFE(fbl->ao_accum_fb);
+	}
+}
+
 void EEVEE_occlusion_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 {
 	EEVEE_PassList *psl = vedata->psl;
@@ -228,6 +270,26 @@ void EEVEE_occlusion_draw_debug(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data
 	}
 }
 
+void EEVEE_occlusion_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
+{
+	EEVEE_FramebufferList *fbl = vedata->fbl;
+	EEVEE_PassList *psl = vedata->psl;
+
+	if (fbl->ao_accum_fb != NULL) {
+		DefaultTextureList *dtxl = DRW_viewport_texture_list_get();
+
+		/* Update the min_max/horizon buffers so the refracion materials appear in it. */
+		EEVEE_create_minmax_buffer(vedata, dtxl->depth, -1);
+		EEVEE_occlusion_compute(sldata, vedata, dtxl->depth, -1);
+
+		DRW_framebuffer_bind(fbl->ao_accum_fb);
+		DRW_draw_pass(psl->ao_accum_ps);
+
+		/* Restore */
+		DRW_framebuffer_bind(fbl->main);
+	}
+}
+
 void EEVEE_occlusion_free(void)
 {
 	DRW_SHADER_FREE_SAFE(e_data.gtao_sh);
diff --git a/source/blender/draw/engines/eevee/eevee_private.h b/source/blender/draw/engines/eevee/eevee_private.h
index 54da57c7a87..0381f841ea7 100644
--- a/source/blender/draw/engines/eevee/eevee_private.h
+++ b/source/blender/draw/engines/eevee/eevee_private.h
@@ -160,6 +160,7 @@ typedef struct EEVEE_PassList {
 	struct DRWPass *ao_horizon_search;
 	struct DRWPass *ao_horizon_search_layer;
 	struct DRWPass *ao_horizon_debug;
+	struct DRWPass *ao_accum_ps;
 	struct DRWPass *mist_accum_ps;
 	struct DRWPass *motion_blur;
 	struct DRWPass *bloom_blit;
@@ -232,6 +233,7 @@ typedef struct EEVEE_FramebufferList {
 	struct GPUFrameBuffer *screen_tracing_fb;
 	struct GPUFrameBuffer *refract_fb;
 	struct GPUFrameBuffer *mist_accum_fb;
+	struct GPUFrameBuffer *ao_accum_fb;
 
 	struct GPUFrameBuffer *update_noise_fb;
 
@@ -254,6 +256,7 @@ typedef struct EEVEE_TextureList {
 	struct GPUTexture *bloom_downsample[MAX_BLOOM_STEP]; /* R16_G16_B16 */
 	struct GPUTexture *bloom_upsample[MAX_BLOOM_STEP - 1]; /* R16_G16_B16 */
 	struct GPUTexture *mist_accum;
+	struct GPUTexture *ao_accum;
 	struct GPUTexture *sss_dir_accum;
 	struct GPUTexture *sss_col_accum;
 	struct GPUTexture *ssr_normal_input;
@@ -814,6 +817,8 @@ void EEVEE_bloom_free(void);
 
 /* eevee_occlusion.c */
 int EEVEE_occlusion_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
+void EEVEE_occlusion_output_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
+void EEVEE_occlusion_output_accumulate(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_occlusion_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_occlusion_compute(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata, struct GPUTexture *depth_src, int layer);
 void EEVEE_occlusion_draw_debug(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata);
diff --git a/source/blender/draw/engines/eevee/eevee_render.c b/source/blender/draw/engines/eevee/eevee_render.c
index 51e8fa241d0..68d575df11c 100644
--- a/source/blender/draw/engines/eevee/eevee_render.c
+++ b/source/blender/draw/engines/eevee/eevee_render.c
@@ -318,6 +318,35 @@ static void eevee_render_result_mist(
 	}
 }
 
+static void eevee_render_result_occlusion(
+        RenderResult *rr, const char *viewname,
+        EEVEE_Data *vedata, EEVEE_ViewLayerData *UNUSED(sldata))
+{
+	const DRWContextState *draw_ctx = DRW_context_state_get();
+	ViewLayer *view_layer = draw_ctx->view_layer;
+
+	if (vedata->fbl->ao_accum_fb == NULL) {
+		/* AO is not enabled. */
+		return;
+	}
+
+	if ((view_layer->passflag & SCE_PASS_AO) != 0) {
+		RenderLayer *rl = rr->layers.first;
+		RenderPass *rp = RE_pass_find_by_name(rl, RE_PASSNAME_AO, viewname);
+
+		IDProperty *props = BKE_view_layer_engine_evaluated_get(view_layer, COLLECTION_MODE_NONE, RE_engine_id_BLENDER_EEVEE);
+		float render_samples = (float)BKE_collection_engine_property_value_get_int(props, "taa_render_samples");
+
+		DRW_framebuffer_bind(vedata->fbl->ao_accum_fb);
+		DRW_framebuffer_read_data(rr->xof, rr->yof, rr->rectx, rr->recty, 3, 0, rp->rect);
+
+		/* This is the accumulated color. Divide by the number of samples. */
+		for (int i = 0; i < rr->rectx * rr->recty * 3; i += 3) {
+			rp->rect[i] = rp->rect[i+1] = rp->rect[i+2] = min_ff(1.0f, rp->rect[i] / render_samples);
+		}
+	}
+}
+
 static void eevee_render_draw_background(EEVEE_Data *vedata)
 {
 	EEVEE_TextureList *txl = vedata->txl;
@@ -373,6 +402,10 @@ void EEVEE_render_draw(EEVEE_Data *vedata, struct RenderEngine *engine, struct D
 		EEVEE_mist_output_init(sldata, vedata);
 	}
 
+	if ((view_layer->passflag & SCE_PASS_AO) != 0) {
+		EEVEE_occlusion_output_init(sldata, vedata);
+	}
+
 	/* Init render result. */
 	const char *viewname = RE_GetActiveRenderView(engine->re);
 	const float *render_size = DRW_viewport_size_get();
@@ -431,7 +464,10 @@ void EEVEE_render_draw(EEVEE_Data *vedata, struct RenderEngine *engine, struct D
 		DRW_draw_pass(psl->refract_depth_pass);
 		DRW_draw_pass(psl->refract_depth_pass_cull);
 		DRW_draw_pass(psl->refract_pass);
+		/* Subsurface output */
 		EEVEE_subsurface_output_accumulate(sldata, vedata);
+		/* Occlusion output */
+		EEVEE_occlusion_output_accumulate(sldata, vedata);
 		/* Result NORMAL */
 		eevee_render_result_normal(rr, viewname, vedata, sldata);
 		/* Volumetrics Resolve Opaque */
@@ -450,6 +486,7 @@ void EEVEE_render_draw(EEVEE_Data *vedata, struct RenderEngine *engine, struct D
 	eevee_render_result_combined(rr, viewname, vedata, sldata);
 	eevee_render_result_subsurface(rr, viewname, vedata, sldata);
 	eevee_render_result_mist(rr, viewname, vedata, sldata);
+	eevee_render_result_occlusion(rr, viewname, vedata, sldata);
 
 	RE_engine_end_result(engine, rr, false, false, false);
 }
@@ -471,6 +508,7 @@ void EEVEE_render_update_passes(RenderEngine *engine, Scene *scene, ViewLayer *v
 	CHECK_PASS(Z,           1, "Z");
 	CHECK_PASS(MIST,        1, "Z");
 	CHECK_PASS(NORMAL,      3, "XYZ");
+	CHECK_PASS(AO,          3, "RGB");
 	CHECK_PASS(SUBSURFACE_COLOR,     3, "RGB");
 	CHECK_PASS(SUBSURFACE_DIRECT,    3, "RGB");