Fluid: Improved OpenVDB support for fluid caches

This commit makes uses of the new OpenVDB IO in Mantaflow (introduced in 781f783a66ac).

From now on, fluid cache files in OpenVDB format will contain a list of grids per frame (before: one .vdb file per grid per frame). Besides regular grids, particle systems are also stored using OpenVDBs PointGrid data structures.

All older cache formats will remain fully functional:
- Uni caches (.uni) files are still available from the UI and can be used as before
- Raw caches (.raw) are no longer available from the UI, but loading them is still possible
- Old OpenVDB caches (one .vdb per grid) can no longer be baked either, but loading them is still possible.

It is also no longer possible to choose file formats for 'Noise' and 'Particles'. Instead there are now options to set the file format for 'Volumetric' and for 'Mesh' data.

Known issues (planned to be resolved soon):
- OpenVDB files are currently not taking into consideration the clipping value (FluidDomainSettings). Empty cells are therefore being written too. Depending on the scene, this can make file sizes unnecessarily large.
- Domains are not being exported at their world position. Instead they are always clipped to the origin.

1 files changed, 25 insertions, 48 deletions

diff --git a/source/blender/blenkernel/intern/fluid.c b/source/blender/blenkernel/intern/fluid.c
index a66454d2bcc..103c3bb119d 100644
--- a/source/blender/blenkernel/intern/fluid.c
+++ b/source/blender/blenkernel/intern/fluid.c
@@ -3809,6 +3809,7 @@ static void BKE_fluid_modifier_processDomain(FluidModifierData *mmd,
   bubble = mds->particle_type & FLUID_DOMAIN_PARTICLE_BUBBLE;
   floater = mds->particle_type & FLUID_DOMAIN_PARTICLE_FOAM;
 
+  bool with_resumable_cache = mds->flags & FLUID_DOMAIN_USE_RESUMABLE_CACHE;
   bool with_script, with_adaptive, with_noise, with_mesh, with_particles, with_guide;
   with_script = mds->flags & FLUID_DOMAIN_EXPORT_MANTA_SCRIPT;
   with_adaptive = mds->flags & FLUID_DOMAIN_USE_ADAPTIVE_DOMAIN;
@@ -3868,13 +3869,7 @@ static void BKE_fluid_modifier_processDomain(FluidModifierData *mmd,
 
   /* Cache mode specific settings. */
   switch (mode) {
-    case FLUID_DOMAIN_CACHE_FINAL:
-      /* Just load the data that has already been baked */
-      if (!baking_data && !baking_noise && !baking_mesh && !baking_particles && !baking_guide) {
-        read_cache = true;
-        bake_cache = false;
-      }
-      break;
+    case FLUID_DOMAIN_CACHE_ALL:
     case FLUID_DOMAIN_CACHE_MODULAR:
       /* Just load the data that has already been baked */
       if (!baking_data && !baking_noise && !baking_mesh && !baking_particles && !baking_guide) {
@@ -3929,6 +3924,7 @@ static void BKE_fluid_modifier_processDomain(FluidModifierData *mmd,
       break;
   }
 
+  bool read_partial = false, read_all = false;
   /* Try to read from cache and keep track of read success. */
   if (read_cache) {
 
@@ -3937,20 +3933,16 @@ static void BKE_fluid_modifier_processDomain(FluidModifierData *mmd,
       has_config = manta_read_config(mds->fluid, mmd, mesh_frame);
 
       /* Update mesh data from file is faster than via Python (manta_read_mesh()). */
-      has_mesh = manta_update_mesh_structures(mds->fluid, mmd, mesh_frame);
+      has_mesh = manta_read_mesh(mds->fluid, mmd, mesh_frame);
     }
 
     /* Read particles cache. */
     if (with_liquid && with_particles) {
       has_config = manta_read_config(mds->fluid, mmd, particles_frame);
 
-      if (!baking_data && !baking_particles && next_particles) {
-        /* Update particle data from file is faster than via Python (manta_read_particles()). */
-        has_particles = manta_update_particle_structures(mds->fluid, mmd, particles_frame);
-      }
-      else {
-        has_particles = manta_read_particles(mds->fluid, mmd, particles_frame);
-      }
+      read_partial = !baking_data && !baking_particles && next_particles;
+      read_all = !read_partial && with_resumable_cache;
+      has_particles = manta_read_particles(mds->fluid, mmd, particles_frame, read_all);
     }
 
     /* Read guide cache. */
@@ -3968,12 +3960,10 @@ static void BKE_fluid_modifier_processDomain(FluidModifierData *mmd,
           manta_needs_realloc(mds->fluid, mmd)) {
         BKE_fluid_reallocate_fluid(mds, mds->res, 1);
       }
-      if (!baking_data && !baking_noise && next_noise) {
-        has_noise = manta_update_noise_structures(mds->fluid, mmd, noise_frame);
-      }
-      else {
-        has_noise = manta_read_noise(mds->fluid, mmd, noise_frame);
-      }
+
+      read_partial = !baking_data && !baking_noise && next_noise;
+      read_all = !read_partial && with_resumable_cache;
+      has_noise = manta_read_noise(mds->fluid, mmd, noise_frame, read_all);
 
       /* When using the adaptive domain, copy all data that was read to a new fluid object. */
       if (with_adaptive && baking_noise) {
@@ -3987,12 +3977,10 @@ static void BKE_fluid_modifier_processDomain(FluidModifierData *mmd,
               mds, o_res, mds->res, o_min, mds->res_min, o_max, o_shift, mds->shift);
         }
       }
-      if (!baking_data && !baking_noise && next_data && next_noise) {
-        /* Nothing to do here since we already loaded noise grids. */
-      }
-      else {
-        has_data = manta_read_data(mds->fluid, mmd, data_frame);
-      }
+
+      read_partial = !baking_data && !baking_noise && next_data && next_noise;
+      read_all = !read_partial && with_resumable_cache;
+      has_data = manta_read_data(mds->fluid, mmd, data_frame, read_all);
     }
     /* Read data cache only */
     else {
@@ -4003,28 +3991,17 @@ static void BKE_fluid_modifier_processDomain(FluidModifierData *mmd,
         if (has_config && manta_needs_realloc(mds->fluid, mmd)) {
           BKE_fluid_reallocate_fluid(mds, mds->res, 1);
         }
-        /* Read data cache */
-        if (!baking_data && !baking_particles && !baking_mesh && next_data) {
-          has_data = manta_update_smoke_structures(mds->fluid, mmd, data_frame);
-        }
-        else {
-          has_data = manta_read_data(mds->fluid, mmd, data_frame);
-        }
-      }
-      if (with_liquid) {
-        if (!baking_data && !baking_particles && !baking_mesh && next_data) {
-          has_data = manta_update_liquid_structures(mds->fluid, mmd, data_frame);
-        }
-        else {
-          has_data = manta_read_data(mds->fluid, mmd, data_frame);
-        }
       }
+
+      read_partial = !baking_data && !baking_particles && !baking_mesh && next_data;
+      read_all = !read_partial && with_resumable_cache;
+      has_data = manta_read_data(mds->fluid, mmd, data_frame, read_all);
     }
   }
 
   /* Cache mode specific settings */
   switch (mode) {
-    case FLUID_DOMAIN_CACHE_FINAL:
+    case FLUID_DOMAIN_CACHE_ALL:
     case FLUID_DOMAIN_CACHE_MODULAR:
       if (!baking_data && !baking_noise && !baking_mesh && !baking_particles && !baking_guide) {
         bake_cache = false;
@@ -4987,12 +4964,12 @@ void BKE_fluid_modifier_create_type_data(struct FluidModifierData *mmd)
 
     /* OpenVDB cache options */
 #ifdef WITH_OPENVDB_BLOSC
-    mmd->domain->openvdb_comp = VDB_COMPRESSION_BLOSC;
+    mmd->domain->openvdb_compression = VDB_COMPRESSION_BLOSC;
 #else
-    mmd->domain->openvdb_comp = VDB_COMPRESSION_ZIP;
+    mmd->domain->openvdb_compression = VDB_COMPRESSION_ZIP;
 #endif
     mmd->domain->clipping = 1e-6f;
-    mmd->domain->data_depth = 0;
+    mmd->domain->openvdb_data_depth = 0;
   }
   else if (mmd->type & MOD_FLUID_TYPE_FLOW) {
     if (mmd->flow) {
@@ -5229,9 +5206,9 @@ void BKE_fluid_modifier_copy(const struct FluidModifierData *mmd,
     }
 
     /* OpenVDB cache options */
-    tmds->openvdb_comp = mds->openvdb_comp;
+    tmds->openvdb_compression = mds->openvdb_compression;
     tmds->clipping = mds->clipping;
-    tmds->data_depth = mds->data_depth;
+    tmds->openvdb_data_depth = mds->openvdb_data_depth;
   }
   else if (tmmd->flow) {
     FluidFlowSettings *tmfs = tmmd->flow;