Eevee: Volumetrics: Support Smoke simulation textures.

It should behave like cycles.

Even if not efficient at all, we still do the same create - draw - free process that was done in the old viewport to save vram (maybe not really the case now) and not care about simulation's GPU texture state sync.

9 files changed, 158 insertions, 11 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_effects.c b/source/blender/draw/engines/eevee/eevee_effects.c
index d3c22ed29f4..f5e47cb0a9d 100644
--- a/source/blender/draw/engines/eevee/eevee_effects.c
+++ b/source/blender/draw/engines/eevee/eevee_effects.c
@@ -30,12 +30,15 @@
 
 #include "DNA_anim_types.h"
 #include "DNA_camera_types.h"
+#include "DNA_object_force.h"
 #include "DNA_screen_types.h"
+#include "DNA_smoke_types.h"
 #include "DNA_view3d_types.h"
 #include "DNA_world_types.h"
 
 #include "BKE_global.h" /* for G.debug_value */
 #include "BKE_camera.h"
+#include "BKE_modifier.h"
 #include "BKE_mesh.h"
 #include "BKE_object.h"
 #include "BKE_animsys.h"
@@ -49,6 +52,7 @@
 #include "BLI_rand.h"
 
 #include "eevee_private.h"
+#include "GPU_draw.h"
 #include "GPU_extensions.h"
 #include "GPU_framebuffer.h"
 #include "GPU_texture.h"
@@ -117,6 +121,9 @@ static struct {
 	struct GPUTexture *depth_src;
 	struct GPUTexture *color_src;
 
+	/* List of all smoke domains rendered within this frame. */
+	ListBase smoke_domains;
+
 	int depth_src_layer;
 	float cube_texel_size;
 } e_data = {NULL}; /* Engine data */
@@ -265,6 +272,8 @@ void EEVEE_effects_init(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata)
 
 	const float *viewport_size = DRW_viewport_size_get();
 
+	BLI_listbase_clear(&e_data.smoke_domains);
+
 	/* Shaders */
 	if (!e_data.motion_blur_sh) {
 		DynStr *ds_frag = BLI_dynstr_new();
@@ -721,11 +730,17 @@ void EEVEE_effects_init(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata)
 		double ht_point[3];
 		double ht_offset[3] = {0.0, 0.0};
 		unsigned int ht_primes[3] = {3, 7, 2};
-		struct wmWindowManager *wm = CTX_wm_manager(draw_ctx->evil_C);
 		unsigned int current_sample = 0;
 
-		if (((effects->enabled_effects & EFFECT_TAA) != 0) && (ED_screen_animation_no_scrub(wm) == NULL)) {
-			/* If TAA is in use do not use the history buffer. */
+		/* If TAA is in use do not use the history buffer. */
+		bool do_taa = ((effects->enabled_effects & EFFECT_TAA) != 0);
+
+		if (draw_ctx->evil_C != NULL) {
+			struct wmWindowManager *wm = CTX_wm_manager(draw_ctx->evil_C);
+			do_taa = do_taa && (ED_screen_animation_no_scrub(wm) == NULL);
+		}
+
+		if (do_taa) {
 			volumetrics->history_alpha = 0.0f;
 			current_sample = effects->taa_current_sample - 1;
 			effects->volume_current_sample = -1;
@@ -1043,6 +1058,7 @@ void EEVEE_effects_cache_volume_object_add(EEVEE_SceneLayerData *sldata, EEVEE_D
 {
 	float *texcoloc = NULL;
 	float *texcosize = NULL;
+	struct ModifierData *md = NULL;
 	EEVEE_VolumetricsInfo *volumetrics = sldata->volumetrics;
 	Material *ma = give_current_material(ob, 1);
 
@@ -1069,6 +1085,34 @@ void EEVEE_effects_cache_volume_object_add(EEVEE_SceneLayerData *sldata, EEVEE_D
 		DRW_shgroup_uniform_vec3(grp, "volume_param", (float *)volumetrics->depth_param, 1);
 		DRW_shgroup_uniform_vec3(grp, "volume_jitter", (float *)volumetrics->jitter, 1);
 	}
+
+	/* Smoke Simulation */
+	if (((ob->base_flag & BASE_FROMDUPLI) == 0) &&
+	    (md = modifiers_findByType(ob, eModifierType_Smoke)) &&
+	    (modifier_isEnabled(scene, md, eModifierMode_Realtime)))
+	{
+		SmokeModifierData *smd = (SmokeModifierData *)md;
+		SmokeDomainSettings *sds = smd->domain;
+		/* Don't show smoke before simulation starts, this could be made an option in the future. */
+		const bool show_smoke = (CFRA >= sds->point_cache[0]->startframe);
+
+		if (sds->fluid && show_smoke) {
+			if (!sds->wt || !(sds->viewsettings & MOD_SMOKE_VIEW_SHOWBIG)) {
+				GPU_create_smoke(smd, 0);
+			}
+			else if (sds->wt && (sds->viewsettings & MOD_SMOKE_VIEW_SHOWBIG)) {
+				GPU_create_smoke(smd, 1);
+			}
+			BLI_addtail(&e_data.smoke_domains, BLI_genericNodeN(smd));
+		}
+
+		if (sds->tex != NULL) {
+			DRW_shgroup_uniform_buffer(grp, "sampdensity", &sds->tex);
+		}
+		if (sds->tex_flame != NULL) {
+			DRW_shgroup_uniform_buffer(grp, "sampflame", &sds->tex_flame);
+		}
+	}
 }
 
 void EEVEE_effects_cache_init(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata)
@@ -1887,6 +1931,16 @@ void EEVEE_draw_effects(EEVEE_Data *vedata)
 	}
 }
 
+void EEVEE_effects_free_smoke_texture(void)
+{
+	/* Free Smoke Textures after rendering */
+	for (LinkData *link = e_data.smoke_domains.first; link; link = link->next) {
+		SmokeModifierData *smd = (SmokeModifierData *)link->data;
+		GPU_free_smoke(smd);
+	}
+	BLI_freelistN(&e_data.smoke_domains);
+}
+
 void EEVEE_effects_free(void)
 {
 	MEM_SAFE_FREE(e_data.volumetric_common_lib);
diff --git a/source/blender/draw/engines/eevee/eevee_engine.c b/source/blender/draw/engines/eevee/eevee_engine.c
index 4617d44ef45..12e4c12b148 100644
--- a/source/blender/draw/engines/eevee/eevee_engine.c
+++ b/source/blender/draw/engines/eevee/eevee_engine.c
@@ -277,6 +277,8 @@ static void EEVEE_draw_scene(void *vedata)
 		}
 	}
 
+	EEVEE_effects_free_smoke_texture();
+
 	stl->g_data->view_updated = false;
 }
 
diff --git a/source/blender/draw/engines/eevee/eevee_private.h b/source/blender/draw/engines/eevee/eevee_private.h
index 20353fdc512..38d4a4b52e1 100644
--- a/source/blender/draw/engines/eevee/eevee_private.h
+++ b/source/blender/draw/engines/eevee/eevee_private.h
@@ -643,6 +643,7 @@ void EEVEE_effects_do_ssr(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_effects_do_refraction(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_effects_do_gtao(EEVEE_SceneLayerData *sldata, EEVEE_Data *vedata);
 void EEVEE_draw_effects(EEVEE_Data *vedata);
+void EEVEE_effects_free_smoke_texture(void);
 void EEVEE_effects_free(void);
 
 /* Shadow Matrix */
diff --git a/source/blender/gpu/GPU_material.h b/source/blender/gpu/GPU_material.h
index 1508941f706..de274b87f9e 100644
--- a/source/blender/gpu/GPU_material.h
+++ b/source/blender/gpu/GPU_material.h
@@ -82,11 +82,12 @@ typedef enum GPUType {
 
 	/* Values not in GPU_DATATYPE_STR */
 	GPU_TEX2D = 1002,
-	GPU_SHADOW2D = 1003,
-	GPU_TEXCUBE = 1004,
+	GPU_TEX3D = 1003,
+	GPU_SHADOW2D = 1004,
+	GPU_TEXCUBE = 1005,
 
 	/* GLSL Struct types */
-	GPU_CLOSURE = 1005,
+	GPU_CLOSURE = 1006,
 
 	/* Opengl Attributes */
 	GPU_ATTRIB = 3001
@@ -108,7 +109,9 @@ typedef enum GPUBuiltin {
 	GPU_PARTICLE_ANG_VELOCITY = (1 << 12),
 	GPU_LOC_TO_VIEW_MATRIX =    (1 << 13),
 	GPU_INVERSE_LOC_TO_VIEW_MATRIX = (1 << 14),
-	GPU_OBJECT_INFO =           (1 << 15)
+	GPU_OBJECT_INFO =           (1 << 15),
+	GPU_VOLUME_DENSITY =        (1 << 16),
+	GPU_VOLUME_FLAME =          (1 << 17)
 } GPUBuiltin;
 
 typedef enum GPUOpenGLBuiltin {
diff --git a/source/blender/gpu/intern/gpu_codegen.c b/source/blender/gpu/intern/gpu_codegen.c
index b5a7d751f2a..bc91df895c8 100644
--- a/source/blender/gpu/intern/gpu_codegen.c
+++ b/source/blender/gpu/intern/gpu_codegen.c
@@ -190,6 +190,9 @@ static void gpu_parse_functions_string(GHash *hash, char *code)
 			if (!type && gpu_str_prefix(code, "sampler2D")) {
 				type = GPU_TEX2D;
 			}
+			if (!type && gpu_str_prefix(code, "sampler3D")) {
+				type = GPU_TEX3D;
+			}
 
 			if (!type && gpu_str_prefix(code, "Closure")) {
 				type = GPU_CLOSURE;
@@ -420,6 +423,10 @@ const char *GPU_builtin_name(GPUBuiltin builtin)
 		return "unfparticleangvel";
 	else if (builtin == GPU_OBJECT_INFO)
 		return "unfobjectinfo";
+	else if (builtin == GPU_VOLUME_DENSITY)
+		return "sampdensity";
+	else if (builtin == GPU_VOLUME_FLAME)
+		return "sampflame";
 	else
 		return "";
 }
@@ -537,7 +544,14 @@ static int codegen_process_uniforms_functions(GPUMaterial *material, DynStr *ds,
 					builtins |= input->builtin;
 					name = GPU_builtin_name(input->builtin);
 
-					if (gpu_str_prefix(name, "unf")) {
+					if (gpu_str_prefix(name, "samp")) {
+						if ((input->builtin == GPU_VOLUME_DENSITY) ||
+						    (input->builtin == GPU_VOLUME_FLAME))
+						{
+							BLI_dynstr_appendf(ds, "uniform sampler3D %s;\n", name);
+						}
+					}
+					else if (gpu_str_prefix(name, "unf")) {
 						BLI_dynstr_appendf(ds, "uniform %s %s;\n",
 							GPU_DATATYPE_STR[input->type], name);
 					}
diff --git a/source/blender/gpu/intern/gpu_draw.c b/source/blender/gpu/intern/gpu_draw.c
index cc6afe983ca..9f1fdcfe551 100644
--- a/source/blender/gpu/intern/gpu_draw.c
+++ b/source/blender/gpu/intern/gpu_draw.c
@@ -1259,6 +1259,16 @@ void GPU_create_smoke(SmokeModifierData *smd, int highres)
 			else {
 				sds->tex = GPU_texture_create_3D_custom(sds->res[0], sds->res[1], sds->res[2], 1,
 				                                 GPU_R8, smoke_get_density(sds->fluid), NULL);
+
+				/* Swizzle the RGBA components to read the Red channel so
+				 * that the shader stay the same for colored and non color
+				 * density textures. */
+				GPU_texture_bind(sds->tex, 0);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_R, GL_RED);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_G, GL_RED);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_B, GL_RED);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_A, GL_RED);
+				GPU_texture_unbind(sds->tex);
 			}
 			sds->tex_flame = (smoke_has_fuel(sds->fluid)) ?
 			                  GPU_texture_create_3D_custom(sds->res[0], sds->res[1], sds->res[2], 1,
@@ -1277,6 +1287,16 @@ void GPU_create_smoke(SmokeModifierData *smd, int highres)
 			else {
 				sds->tex = GPU_texture_create_3D_custom(sds->res_wt[0], sds->res_wt[1], sds->res_wt[2], 1,
 				                                        GPU_R8, smoke_turbulence_get_density(sds->wt), NULL);
+
+				/* Swizzle the RGBA components to read the Red channel so
+				 * that the shader stay the same for colored and non color
+				 * density textures. */
+				GPU_texture_bind(sds->tex, 0);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_R, GL_RED);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_G, GL_RED);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_B, GL_RED);
+				glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_SWIZZLE_A, GL_RED);
+				GPU_texture_unbind(sds->tex);
 			}
 			sds->tex_flame = (smoke_turbulence_has_fuel(sds->wt)) ?
 			                  GPU_texture_create_3D_custom(sds->res_wt[0], sds->res_wt[1], sds->res_wt[2], 1,
diff --git a/source/blender/gpu/intern/gpu_material.c b/source/blender/gpu/intern/gpu_material.c
index 312cd7bc20a..cdd3f789cca 100644
--- a/source/blender/gpu/intern/gpu_material.c
+++ b/source/blender/gpu/intern/gpu_material.c
@@ -2401,6 +2401,7 @@ GPUShaderExport *GPU_shader_export(struct Scene *scene, struct Material *ma)
 						break;
 
 					case GPU_NONE:
+					case GPU_TEX3D:
 					case GPU_TEXCUBE:
 					case GPU_FLOAT:
 					case GPU_VEC2:
@@ -2439,6 +2440,7 @@ GPUShaderExport *GPU_shader_export(struct Scene *scene, struct Material *ma)
 					case GPU_NONE:
 					case GPU_CLOSURE:
 					case GPU_TEX2D:
+					case GPU_TEX3D:
 					case GPU_TEXCUBE:
 					case GPU_SHADOW2D:
 					case GPU_ATTRIB:
diff --git a/source/blender/gpu/shaders/gpu_shader_material.glsl b/source/blender/gpu/shaders/gpu_shader_material.glsl
index 0dd8e6643b2..afb5eca5263 100644
--- a/source/blender/gpu/shaders/gpu_shader_material.glsl
+++ b/source/blender/gpu/shaders/gpu_shader_material.glsl
@@ -3093,11 +3093,47 @@ void node_gamma(vec4 col, float gamma, out vec4 outcol)
 
 /* geometry */
 
+void node_attribute_volume_density(sampler3D tex, out vec4 outcol, out vec3 outvec, out float outf)
+{
+#if defined(EEVEE_ENGINE) && defined(MESH_SHADER) && defined(VOLUMETRICS)
+	vec3 cos = volumeObjectLocalCoord;
+#else
+	vec3 cos = vec3(0.0);
+#endif
+	outvec = texture(tex, cos).aaa;
+	outcol = vec4(outvec, 1.0);
+	outf = dot(vec3(1.0 / 3.0), outvec);
+}
+
+void node_attribute_volume_color(sampler3D tex, out vec4 outcol, out vec3 outvec, out float outf)
+{
+#if defined(EEVEE_ENGINE) && defined(MESH_SHADER) && defined(VOLUMETRICS)
+	vec3 cos = volumeObjectLocalCoord;
+#else
+	vec3 cos = vec3(0.0);
+#endif
+	outvec = texture(tex, cos).rgb;
+	outcol = vec4(outvec, 1.0);
+	outf = dot(vec3(1.0 / 3.0), outvec);
+}
+
+void node_attribute_volume_flame(sampler3D tex, out vec4 outcol, out vec3 outvec, out float outf)
+{
+#if defined(EEVEE_ENGINE) && defined(MESH_SHADER) && defined(VOLUMETRICS)
+	vec3 cos = volumeObjectLocalCoord;
+#else
+	vec3 cos = vec3(0.0);
+#endif
+	outvec = texture(tex, cos).rrr;
+	outcol = vec4(outvec, 1.0);
+	outf = dot(vec3(1.0 / 3.0), outvec);
+}
+
 void node_attribute(vec3 attr, out vec4 outcol, out vec3 outvec, out float outf)
 {
 	outcol = vec4(attr, 1.0);
 	outvec = attr;
-	outf = (attr.x + attr.y + attr.z) / 3.0;
+	outf =  dot(vec3(1.0 / 3.0), attr);
 }
 
 void node_uvmap(vec3 attr_uv, out vec3 outvec)
diff --git a/source/blender/nodes/shader/nodes/node_shader_attribute.c b/source/blender/nodes/shader/nodes/node_shader_attribute.c
index 3c9b21a4198..5f3699e52eb 100644
--- a/source/blender/nodes/shader/nodes/node_shader_attribute.c
+++ b/source/blender/nodes/shader/nodes/node_shader_attribute.c
@@ -45,9 +45,24 @@ static void node_shader_init_attribute(bNodeTree *UNUSED(ntree), bNode *node)
 static int node_shader_gpu_attribute(GPUMaterial *mat, bNode *node, bNodeExecData *UNUSED(execdata), GPUNodeStack *in, GPUNodeStack *out)
 {
 	NodeShaderAttribute *attr = node->storage;
-	GPUNodeLink *cd_attr = GPU_attribute(CD_AUTO_FROM_NAME, attr->name);
 
-	return GPU_stack_link(mat, node, "node_attribute", in, out, cd_attr);
+	/* FIXME : if an attribute layer (like vertex color) has one of theses name, it will not work as expected. */
+	if (strcmp(attr->name, "density") == 0) {
+		return GPU_stack_link(mat, node, "node_attribute_volume_density", in, out,
+		                      GPU_builtin(GPU_VOLUME_DENSITY));
+	}
+	else if (strcmp(attr->name, "color") == 0) {
+		return GPU_stack_link(mat, node, "node_attribute_volume_color", in, out,
+		                      GPU_builtin(GPU_VOLUME_DENSITY));
+	}
+	else if (strcmp(attr->name, "flame") == 0) {
+		return GPU_stack_link(mat, node, "node_attribute_volume_flame", in, out,
+		                      GPU_builtin(GPU_VOLUME_FLAME));
+	}
+	else {
+		GPUNodeLink *cd_attr = GPU_attribute(CD_AUTO_FROM_NAME, attr->name);
+		return GPU_stack_link(mat, node, "node_attribute", in, out, cd_attr);
+	}
 }
 
 /* node type definition */