Fix T63377: "Principled Volume" node not working anymore in EEVEE

I'm not sur how it ever worked before. There was no texture bound to these
sampdensity and sampflame when no volume simulation was happening.

This fixes the issue using 1x1x1 dummy textures.

1 files changed, 28 insertions, 12 deletions

diff --git a/source/blender/draw/engines/eevee/eevee_volumes.c b/source/blender/draw/engines/eevee/eevee_volumes.c
index b752aae99f4..245774f5508 100644
--- a/source/blender/draw/engines/eevee/eevee_volumes.c
+++ b/source/blender/draw/engines/eevee/eevee_volumes.c
@@ -57,6 +57,9 @@ static struct {
 	GPUTexture *color_src;
 	GPUTexture *depth_src;
 
+	GPUTexture *dummy_density;
+	GPUTexture *dummy_flame;
+
 	/* List of all smoke domains rendered within this frame. */
 	ListBase smoke_domains;
 } e_data = {NULL}; /* Engine data */
@@ -126,6 +129,12 @@ static void eevee_create_shader_volumes(void)
 	        datatoc_common_fullscreen_vert_glsl, NULL,
 	        datatoc_volumetric_resolve_frag_glsl,
 	        e_data.volumetric_common_lib, NULL);
+
+	float color[4] = {1.0f, 1.0f, 1.0f, 1.0f};
+	e_data.dummy_density = DRW_texture_create_3d(1, 1, 1, GPU_RGBA8, DRW_TEX_WRAP, color);
+
+	float flame = 0.0f;
+	e_data.dummy_flame = DRW_texture_create_3d(1, 1, 1, GPU_R8, DRW_TEX_WRAP, &flame);
 }
 
 void EEVEE_volumes_set_jitter(EEVEE_ViewLayerData *sldata, uint current_sample)
@@ -406,6 +415,11 @@ void EEVEE_volumes_cache_init(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata)
 				DRW_shgroup_uniform_block(grp, "planar_block", sldata->planar_ubo);
 				DRW_shgroup_uniform_block(grp, "light_block", sldata->light_ubo);
 				DRW_shgroup_uniform_block(grp, "shadow_block", sldata->shadow_ubo);
+
+				/* Fix principle volumetric not working with world materials. */
+				DRW_shgroup_uniform_texture(grp, "sampdensity", e_data.dummy_density);
+				DRW_shgroup_uniform_texture(grp, "sampflame", e_data.dummy_flame);
+				DRW_shgroup_uniform_vec2(grp, "unftemperature", (float[2]){0.0f, 1.0f}, 1);
 			}
 		}
 
@@ -468,6 +482,7 @@ typedef struct EEVEE_InstanceVolumeMatrix {
 void EEVEE_volumes_cache_object_add(EEVEE_ViewLayerData *sldata, EEVEE_Data *vedata, Scene *scene, Object *ob)
 {
 	const DRWContextState *draw_ctx = DRW_context_state_get();
+	static float white[3] = {1.0f, 1.0f, 1.0f};
 
 	float *texcoloc = NULL;
 	float *texcosize = NULL;
@@ -522,15 +537,12 @@ void EEVEE_volumes_cache_object_add(EEVEE_ViewLayerData *sldata, EEVEE_Data *ved
 	/* Smoke Simulation */
 	if (((ob->base_flag & BASE_FROM_DUPLI) == 0) &&
 	    (md = modifiers_findByType(ob, eModifierType_Smoke)) &&
-	    (modifier_isEnabled(scene, md, eModifierMode_Realtime)))
+	    (modifier_isEnabled(scene, md, eModifierMode_Realtime)) &&
+	    ((SmokeModifierData *)md)->domain != NULL)
 	{
 		SmokeModifierData *smd = (SmokeModifierData *)md;
 		SmokeDomainSettings *sds = smd->domain;
 
-		if (sds == NULL) {
-			return;
-		}
-
 		/* Don't show smoke before simulation starts, this could be made an option in the future. */
 		const bool show_smoke = ((int)DEG_get_ctime(draw_ctx->depsgraph) >= sds->point_cache[0]->startframe);
 
@@ -545,15 +557,10 @@ void EEVEE_volumes_cache_object_add(EEVEE_ViewLayerData *sldata, EEVEE_Data *ved
 			BLI_addtail(&e_data.smoke_domains, BLI_genericNodeN(smd));
 		}
 
-		if (sds->tex != NULL) {
-			DRW_shgroup_uniform_texture_ref(grp, "sampdensity", &sds->tex);
-		}
-		if (sds->tex_flame != NULL) {
-			DRW_shgroup_uniform_texture_ref(grp, "sampflame", &sds->tex_flame);
-		}
+		DRW_shgroup_uniform_texture_ref(grp, "sampdensity", sds->tex ? &sds->tex : &e_data.dummy_density);
+		DRW_shgroup_uniform_texture_ref(grp, "sampflame", sds->tex_flame ? &sds->tex_flame : &e_data.dummy_flame);
 
 		/* Constant Volume color. */
-		static float white[3] = {1.0f, 1.0f, 1.0f};
 		bool use_constant_color = ((sds->active_fields & SM_ACTIVE_COLORS) == 0 &&
 		                           (sds->active_fields & SM_ACTIVE_COLOR_SET) != 0);
 
@@ -562,6 +569,12 @@ void EEVEE_volumes_cache_object_add(EEVEE_ViewLayerData *sldata, EEVEE_Data *ved
 		/* Output is such that 0..1 maps to 0..1000K */
 		DRW_shgroup_uniform_vec2(grp, "unftemperature", &sds->flame_ignition, 1);
 	}
+	else {
+		DRW_shgroup_uniform_texture(grp, "sampdensity", e_data.dummy_density);
+		DRW_shgroup_uniform_texture(grp, "sampflame", e_data.dummy_flame);
+		DRW_shgroup_uniform_vec3(grp, "volumeColor", white, 1);
+		DRW_shgroup_uniform_vec2(grp, "unftemperature", (float[2]){0.0f, 1.0f}, 1);
+	}
 }
 
 void EEVEE_volumes_compute(EEVEE_ViewLayerData *UNUSED(sldata), EEVEE_Data *vedata)
@@ -644,6 +657,9 @@ void EEVEE_volumes_free(void)
 	MEM_SAFE_FREE(e_data.volumetric_common_lib);
 	MEM_SAFE_FREE(e_data.volumetric_common_lights_lib);
 
+	DRW_TEXTURE_FREE_SAFE(e_data.dummy_density);
+	DRW_TEXTURE_FREE_SAFE(e_data.dummy_flame);
+
 	DRW_SHADER_FREE_SAFE(e_data.volumetric_clear_sh);
 	DRW_SHADER_FREE_SAFE(e_data.volumetric_scatter_sh);
 	DRW_SHADER_FREE_SAFE(e_data.volumetric_scatter_with_lights_sh);