[Bf-blender-cvs] [21485e94aac] master: Fluid: Refactored fluid gravity settings

Sebastián Barschkis noreply at git.blender.org
Thu Apr 30 17:33:36 CEST 2020


Commit: 21485e94aac1bc01d032f666ebc54c6008f4d303
Author: Sebastián Barschkis
Date:   Thu Apr 30 17:32:47 2020 +0200
Branches: master
https://developer.blender.org/rB21485e94aac1bc01d032f666ebc54c6008f4d303

Fluid: Refactored fluid gravity settings

Refactored setup that converts from Blender to Mantaflow units.

===================================================================

M	intern/mantaflow/intern/MANTA_main.cpp
M	intern/mantaflow/intern/strings/fluid_script.h
M	intern/mantaflow/intern/strings/liquid_script.h
M	intern/mantaflow/intern/strings/smoke_script.h
M	source/blender/blenkernel/intern/fluid.c
M	source/blender/makesrna/intern/rna_fluid.c

===================================================================

diff --git a/intern/mantaflow/intern/MANTA_main.cpp b/intern/mantaflow/intern/MANTA_main.cpp
index a56ce4c1f60..9e5d9bf4656 100644
--- a/intern/mantaflow/intern/MANTA_main.cpp
+++ b/intern/mantaflow/intern/MANTA_main.cpp
@@ -711,6 +711,8 @@ std::string MANTA::getRealValue(const std::string &varName, FluidModifierData *m
       ss << mResZ;
     }
   }
+  else if (varName == "TIME_SCALE")
+    ss << mmd->domain->time_scale;
   else if (varName == "FRAME_LENGTH")
     ss << mmd->domain->frame_length;
   else if (varName == "CFL")
diff --git a/intern/mantaflow/intern/strings/fluid_script.h b/intern/mantaflow/intern/strings/fluid_script.h
index dd2111db7d7..c0a23f77d7a 100644
--- a/intern/mantaflow/intern/strings/fluid_script.h
+++ b/intern/mantaflow/intern/strings/fluid_script.h
@@ -92,7 +92,7 @@ const std::string fluid_variables =
 mantaMsg('Fluid variables')\n\
 dim_s$ID$     = $SOLVER_DIM$\n\
 res_s$ID$     = $RES$\n\
-gravity_s$ID$ = vec3($GRAVITY_X$, $GRAVITY_Y$, $GRAVITY_Z$)\n\
+gravity_s$ID$ = vec3($GRAVITY_X$, $GRAVITY_Y$, $GRAVITY_Z$) # in SI unit (e.g. m/s^2)\n\
 gs_s$ID$      = vec3($RESX$, $RESY$, $RESZ$)\n\
 maxVel_s$ID$  = 0\n\
 \n\
@@ -115,6 +115,7 @@ using_speedvectors_s$ID$ = $USING_SPEEDVECTORS$\n\
 using_diffusion_s$ID$    = $USING_DIFFUSION$\n\
 \n\
 # Fluid time params\n\
+timeScale_s$ID$    = $TIME_SCALE$\n\
 timeTotal_s$ID$    = $TIME_TOTAL$\n\
 timePerFrame_s$ID$ = $TIME_PER_FRAME$\n\
 frameLength_s$ID$  = $FRAME_LENGTH$\n\
@@ -132,8 +133,29 @@ end_frame_s$ID$     = $END_FRAME$\n\
 domainSize_s$ID$ = $FLUID_DOMAIN_SIZE$ # longest domain side in meters\n\
 viscosity_s$ID$ = $FLUID_VISCOSITY$ / (domainSize_s$ID$*domainSize_s$ID$) # kinematic viscosity in m^2/s\n\
 \n\
-# Factor to convert blender velocities to manta velocities\n\
-toMantaUnitsFac_s$ID$ = (1.0 / (1.0 / res_s$ID$))\n # = dt/dx * 1/dt ";
+# Factors to convert Blender units to Manta units\n\
+ratioMetersToRes_s$ID$ = float(domainSize_s$ID$) / float(res_s$ID$) # [meters / cells]\n\
+mantaMsg('1 Mantaflow cell is ' + str(ratioMetersToRes_s$ID$) + ' Blender length units long.')\n\
+\n\
+ratioResToBLength_s$ID$ = float(res_s$ID$) / float(domainSize_s$ID$) # [cells / blength] (blength: cm, m, or km, ... )\n\
+mantaMsg('1 Blender length unit is ' + str(ratioResToBLength_s$ID$) + ' Mantaflow cells long.')\n\
+\n\
+ratioBTimeToTimstep_s$ID$ = float(1) / float(0.1 * 25 * timeScale_s$ID$) # the time within 1 blender time unit, see also fluid.c\n\
+mantaMsg('1 Blender time unit is ' + str(ratioBTimeToTimstep_s$ID$) + ' Mantaflow time units long.')\n\
+\n\
+ratioFrameToFramelength_s$ID$ = float(1) / float(frameLength_s$ID$) # the time within 1 frame\n\
+mantaMsg('frame / frameLength is ' + str(ratioFrameToFramelength_s$ID$) + ' Mantaflow time units long.')\n\
+\n\
+scaleAcceleration_s$ID$ = ratioResToBLength_s$ID$ * (ratioBTimeToTimstep_s$ID$**2)# [meters/btime^2] to [cells/timestep^2] (btime: sec, min, or h, ...)\n\
+mantaMsg('scaleAcceleration is ' + str(scaleAcceleration_s$ID$))\n\
+\n\
+scaleSpeedFrames_s$ID$ = ratioResToBLength_s$ID$ * ratioFrameToFramelength_s$ID$ # [blength/frame] to [cells/frameLength]\n\
+mantaMsg('scaleSpeed is ' + str(scaleSpeedFrames_s$ID$))\n\
+\n\
+scaleSpeedTime_s$ID$ = ratioResToBLength_s$ID$ * ratioBTimeToTimstep_s$ID$ # [blength/btime] to [cells/frameLength]\n\
+mantaMsg('scaleSpeedTime is ' + str(scaleSpeedTime_s$ID$))\n\
+\n\
+gravity_s$ID$ *= scaleAcceleration_s$ID$ # scale from world acceleration to cell based acceleration\n";
 
 const std::string fluid_variables_noise =
     "\n\
@@ -342,17 +364,16 @@ def fluid_pre_step_$ID$():\n\
         y_obvel_s$ID$.safeDivide(numObs_s$ID$)\n\
         z_obvel_s$ID$.safeDivide(numObs_s$ID$)\n\
         \n\
-        x_obvel_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
-        y_obvel_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
-        z_obvel_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
-        \n\
+        x_obvel_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
+        y_obvel_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
+        z_obvel_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
         copyRealToVec3(sourceX=x_obvel_s$ID$, sourceY=y_obvel_s$ID$, sourceZ=z_obvel_s$ID$, target=obvelC_s$ID$)\n\
     \n\
     # translate invels (world space) to grid space\n\
     if using_invel_s$ID$:\n\
-        x_invel_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
-        y_invel_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
-        z_invel_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
+        x_invel_s$ID$.multConst(scaleSpeedTime_s$ID$)\n\
+        y_invel_s$ID$.multConst(scaleSpeedTime_s$ID$)\n\
+        z_invel_s$ID$.multConst(scaleSpeedTime_s$ID$)\n\
         copyRealToVec3(sourceX=x_invel_s$ID$, sourceY=y_invel_s$ID$, sourceZ=z_invel_s$ID$, target=invelC_s$ID$)\n\
     \n\
     if using_guiding_s$ID$:\n\
@@ -362,9 +383,9 @@ def fluid_pre_step_$ID$():\n\
         velT_s$ID$.multConst(vec3(gamma_sg$ID$))\n\
     \n\
     # translate external forces (world space) to grid space\n\
-    x_force_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
-    y_force_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
-    z_force_s$ID$.multConst(toMantaUnitsFac_s$ID$)\n\
+    x_force_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
+    y_force_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
+    z_force_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
     copyRealToVec3(sourceX=x_force_s$ID$, sourceY=y_force_s$ID$, sourceZ=z_force_s$ID$, target=forces_s$ID$)\n\
     \n\
     # If obstacle has velocity, i.e. is a moving obstacle, switch to dynamic preconditioner\n\
@@ -598,10 +619,9 @@ def bake_guiding_process_$ID$(framenr, format_guiding, path_guiding, resumable):
     y_guidevel_s$ID$.safeDivide(numGuides_s$ID$)\n\
     z_guidevel_s$ID$.safeDivide(numGuides_s$ID$)\n\
     \n\
-    x_guidevel_s$ID$.multConst(Real(toMantaUnitsFac_s$ID$))\n\
-    y_guidevel_s$ID$.multConst(Real(toMantaUnitsFac_s$ID$))\n\
-    z_guidevel_s$ID$.multConst(Real(toMantaUnitsFac_s$ID$))\n\
-    \n\
+    x_guidevel_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
+    y_guidevel_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
+    z_guidevel_s$ID$.multConst(scaleSpeedFrames_s$ID$)\n\
     copyRealToVec3(sourceX=x_guidevel_s$ID$, sourceY=y_guidevel_s$ID$, sourceZ=z_guidevel_s$ID$, target=guidevelC_s$ID$)\n\
     \n\
     mantaMsg('Extrapolating guiding velocity')\n\
diff --git a/intern/mantaflow/intern/strings/liquid_script.h b/intern/mantaflow/intern/strings/liquid_script.h
index f20b218427c..3aedde6753f 100644
--- a/intern/mantaflow/intern/strings/liquid_script.h
+++ b/intern/mantaflow/intern/strings/liquid_script.h
@@ -67,8 +67,7 @@ lMax_sp$ID$ = $SNDPARTICLE_L_MAX$\n\
 c_s_sp$ID$ = 0.4   # classification constant for snd parts\n\
 c_b_sp$ID$ = 0.77  # classification constant for snd parts\n\
 pot_radius_sp$ID$ = $SNDPARTICLE_POTENTIAL_RADIUS$\n\
-update_radius_sp$ID$ = $SNDPARTICLE_UPDATE_RADIUS$\n\
-scaleFromManta_sp$ID$ = $FLUID_DOMAIN_SIZE$ / float(res_s$ID$) # resize factor for snd parts\n";
+update_radius_sp$ID$ = $SNDPARTICLE_UPDATE_RADIUS$\n";
 
 //////////////////////////////////////////////////////////////////////
 // GRIDS & MESH & PARTICLESYSTEM
@@ -263,7 +262,7 @@ def liquid_step_$ID$():\n\
     velOld_s$ID$.copyFrom(vel_s$ID$)\n\
     \n\
     # forces & pressure solve\n\
-    addGravity(flags=flags_s$ID$, vel=vel_s$ID$, gravity=gravity_s$ID$)\n\
+    addGravity(flags=flags_s$ID$, vel=vel_s$ID$, gravity=gravity_s$ID$, scale=False)\n\
     \n\
     mantaMsg('Adding external forces')\n\
     addForceField(flags=flags_s$ID$, vel=vel_s$ID$, force=forces_s$ID$)\n\
@@ -371,7 +370,7 @@ def liquid_step_particles_$ID$():\n\
     flags_sp$ID$.updateFromLevelset(levelset=phi_sp$ID$)\n\
     \n\
     # Actual secondary particle simulation\n\
-    flipComputeSecondaryParticlePotentials(potTA=trappedAir_sp$ID$, potWC=waveCrest_sp$ID$, potKE=kineticEnergy_sp$ID$, neighborRatio=neighborRatio_sp$ID$, flags=flags_sp$ID$, v=vel_sp$ID$, normal=normal_sp$ID$, phi=phi_sp$ID$, radius=pot_radius_sp$ID$, tauMinTA=tauMin_ta_sp$ID$, tauMaxTA=tauMax_ta_sp$ID$, tauMinWC=tauMin_wc_sp$ID$, tauMaxWC=tauMax_wc_sp$ID$, tauMinKE=tauMin_k_sp$ID$, tauMaxKE=tauMax_k_sp$ID$, scaleFromManta=scaleFromManta_sp$ID$)\n\
+    flipComputeSecondaryParticlePotentials(potTA=trappedAir_sp$ID$, potWC=waveCrest_sp$ID$, potKE=kineticEnergy_sp$ID$, neighborRatio=neighborRatio_sp$ID$, flags=flags_sp$ID$, v=vel_sp$ID$, normal=normal_sp$ID$, phi=phi_sp$ID$, radius=pot_radius_sp$ID$, tauMinTA=tauMin_ta_sp$ID$, tauMaxTA=tauMax_ta_sp$ID$, tauMinWC=tauMin_wc_sp$ID$, tauMaxWC=tauMax_wc_sp$ID$, tauMinKE=tauMin_k_sp$ID$, tauMaxKE=tauMax_k_sp$ID$, scaleFromManta=ratioMetersToRes_s$ID$)\n\
     flipSampleSecondaryParticles(mode='single', flags=flags_sp$ID$, v=vel_sp$ID$, pts_sec=ppSnd_sp$ID$, v_sec=pVelSnd_pp$ID$, l_sec=pLifeSnd_pp$ID$, lMin=lMin_sp$ID$, lMax=lMax_sp$ID$, potTA=trappedAir_sp$ID$, potWC=waveCrest_sp$ID$, potKE=kineticEnergy_sp$ID$, neighborRatio=neighborRatio_sp$ID$, c_s=c_s_sp$ID$, c_b=c_b_sp$ID$, k_ta=k_ta_sp$ID$, k_wc=k_wc_sp$ID$, dt=sp$ID$.timestep)\n\
     flipUpdateSecondaryParticles(mode='linear', pts_sec=ppSnd_sp$ID$, v_sec=pVelSnd_pp$ID$, l_sec=pLifeSnd_pp$ID$, f_sec=pForceSnd_pp$ID$, flags=flags_sp$ID$, v=vel_sp$ID$, neighborRatio=neighborRatio_sp$ID$, radius=update_radius_sp$ID$, gravity=gravity_s$ID$, k_b=k_b_sp$ID$, k_d=k_d_sp$ID$, c_s=c_s_sp$ID$, c_b=c_b_sp$ID$, dt=sp$ID$.timestep)\n\
     if $SNDPARTICLE_BOUNDARY_PUSHOUT$:\n\
diff --git a/intern/mantaflow/intern/strings/smoke_script.h b/intern/mantaflow/intern/strings/smoke_script.h
index fdb58543cec..ea2b1e9d848 100644
--- a/intern/mantaflow/intern/strings/smoke_script.h
+++ b/intern/mantaflow/intern/strings/smoke_script.h
@@ -376,9 +376,9 @@ def smoke_step_$ID$():\n\
     \n\
     if using_heat_s$ID$:\n\
         mantaMsg('Adding heat buoyancy')\n\
-        addBuoyancy(flags=flags_s$ID$, density=heat_s$ID$, vel=vel_s$ID$, gravity=gravity_s$ID$, coefficient=buoyancy_heat_s$ID$)\n\
+        addBuoyancy(flags=flags_s$ID$, density=heat_s$ID$, vel=vel_s$ID$, gravity=gravity_s$ID$, coefficient=buoyancy_heat_s$ID$, scale=False)\n\
     mantaMsg('Adding buoyancy')\n\
-    addBuoyancy(flags=flags_s$ID$, density=density_s$ID$, vel=vel_s$ID$, gravity=gravity_s$ID$, coefficient=buoyancy_de

@@ Diff output truncated at 10240 characters. @@



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