Fix T77264: Mantaflow: Liquid checkbox doesn't turn on while switching

between fluid types

When switching to gas, the fluids were not actually destroyed, leading to
the situation that they were then destroyed when actually switching to
liquid.

Maniphest Tasks: T77264

Differential Revision: https://developer.blender.org/D7907

1 files changed, 4 insertions, 1 deletions

diff --git a/source/blender/makesrna/intern/rna_fluid.c b/source/blender/makesrna/intern/rna_fluid.c
index 93c7c1f3480..43d2234ddf2 100644
--- a/source/blender/makesrna/intern/rna_fluid.c
+++ b/source/blender/makesrna/intern/rna_fluid.c
@@ -227,8 +227,11 @@ static void rna_Fluid_flip_parts_update(Main *bmain, Scene *scene, PointerRNA *p
   mmd = (FluidModifierData *)BKE_modifiers_findby_type(ob, eModifierType_Fluid);
   bool exists = rna_Fluid_parts_exists(ptr, PART_FLUID_FLIP);
 
-  /* Only create a particle system in liquid domain mode. */
+  /* Only create a particle system in liquid domain mode.
+   * Remove any remainings of a liquid sim when switching to gas. */
   if (mmd->domain->type != FLUID_DOMAIN_TYPE_LIQUID) {
+    rna_Fluid_parts_delete(ptr, PART_FLUID_FLIP);
+    mmd->domain->particle_type &= ~FLUID_DOMAIN_PARTICLE_FLIP;
     rna_Fluid_domain_reset(bmain, scene, ptr);
     return;
   }