[Bf-blender-cvs] [ff2c67d7e8e] master: Fluid: Disable subframes when using adaptive time-steps in the first frame

[Sebastián Barschkis]

Commit: ff2c67d7e8ed334c482681e2342bf8cce0957546
Author: Sebastián Barschkis
Date:   Wed Apr 8 13:42:40 2020 +0200
Branches: master
https://developer.blender.org/rBff2c67d7e8ed334c482681e2342bf8cce0957546

Fluid: Disable subframes when using adaptive time-steps in the first frame

First frame should only produce inflow once and not compute the emission for the frame before the first frame. Problem became evident in T74062.

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

M	source/blender/blenkernel/intern/fluid.c

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

diff --git a/source/blender/blenkernel/intern/fluid.c b/source/blender/blenkernel/intern/fluid.c
index 985d0a79b23..e96f65751de 100644
--- a/source/blender/blenkernel/intern/fluid.c
+++ b/source/blender/blenkernel/intern/fluid.c
@@ -1250,7 +1250,8 @@ static void update_obstacles(Depsgraph *depsgraph,
 
         /* Set scene time */
         /* Handle emission subframe */
-        if (subframe < subframes || time_per_frame + dt + FLT_EPSILON < frame_length) {
+        if ((subframe < subframes || time_per_frame + dt + FLT_EPSILON < frame_length) &&
+            !is_first_frame) {
           scene->r.subframe = (time_per_frame + (subframe + 1.0f) * subframe_dt) / frame_length;
           scene->r.cfra = frame - 1;
         }
@@ -2763,7 +2764,8 @@ static void update_flowsfluids(struct Depsgraph *depsgraph,
         FluidObjectBB bb_temp = {NULL};
 
         /* Set scene time */
-        if (subframe < subframes || time_per_frame + dt + FLT_EPSILON < frame_length) {
+        if ((subframe < subframes || time_per_frame + dt + FLT_EPSILON < frame_length) &&
+            !is_first_frame) {
           scene->r.subframe = (time_per_frame + (subframe + 1.0f) * subframe_dt) / frame_length;
           scene->r.cfra = frame - 1;
         }