Bugfix [#29186] Object contribute to fluid sim animation start earlier than keyframe

Also fix:
- Fluid simulation was always lagging 1 frame behind: E.g. the 250th frame in blender showed 249th frame of the fluid simulation.

Change:
- Animated enabled/disabled property only gets counted as "on" if value >= 1

Note that this bugfix should solve many problems with timings of animated fluid sim properties.

intern/elbeem/intern/ntl_geometryobject.cpp

@@ -787,7 +787,7 @@ ntlVec3Gfx ntlGeometryObject::getTranslation(double t) {
 }
 /*! get active flag time t*/
 float ntlGeometryObject::getGeoActive(double t) {
-	float act = mcGeoActive.get(t); // if <= 0.0 -> off
+	float act = (mcGeoActive.get(t) >= 1.) ? 1.0 : 0.0; 
 	return act;
 }
 

intern/elbeem/intern/ntl_world.cpp

@@ -143,6 +143,7 @@ void ntlWorld::initDefaults()
 	mFirstSim = 1;
 	mSingleStepDebug =  false;
 	mFrameCnt = 0;
+	mSimFrameCnt = 0;
 	mpOpenGLRenderer = NULL;
 
   /* create scene storage */
@@ -406,7 +407,6 @@ int ntlWorld::advanceSims(int framenum)
 	}
 
 	for(size_t i=0;i<mpSims->size();i++) { (*mpSims)[i]->setFrameNum(framenum); }
-	double targetTime = mSimulationTime + (*mpSims)[mFirstSim]->getFrameTime(framenum);
 
 	// time stopped? nothing else to do...
 	if( (*mpSims)[mFirstSim]->getFrameTime(framenum) <= 0.0 ){ 
@@ -416,6 +416,13 @@ int ntlWorld::advanceSims(int framenum)
 		(*mpSims)[mFirstSim]->checkCallerStatus(FLUIDSIM_CBSTATUS_STEP, 0);
 	}
 
+	// Prevent bug [#29186] Object contribute to fluid sim animation start earlier than keyframe
+	// Was: double targetTime = mSimulationTime + (*mpSims)[mFirstSim]->getFrameTime(framenum); - DG
+	double totalTime = 0.0, targetTime = 0.0;
+	for(size_t i = 0; i < mSimFrameCnt; i++)
+		totalTime += (*mpSims)[mFirstSim]->getFrameTime(framenum);
+	targetTime = totalTime + (*mpSims)[mFirstSim]->getFrameTime(framenum);
+
 	int gstate = 0;
 	myTime_t advsstart = getTime();
 
@@ -461,6 +468,8 @@ int ntlWorld::advanceSims(int framenum)
 		sim->prepareVisualization();
 	}
 
+	mSimFrameCnt++;
+
 	return 0;
 }
 

intern/elbeem/intern/ntl_world.h

@@ -115,6 +115,9 @@ class ntlWorld
 
 		/*! count no. of frame for viz render */
 		int mFrameCnt;
+
+		/*! count no. of frame for correct sim time */
+		int mSimFrameCnt;
 };
 
 

source/blender/editors/physics/physics_fluid.c

@@ -446,7 +446,7 @@ static void fluid_init_all_channels(bContext *C, Object *UNUSED(fsDomain), Fluid
 		for (fobj=fobjects->first; fobj; fobj=fobj->next) {
 			Object *ob = fobj->object;
 			FluidsimModifierData *fluidmd = (FluidsimModifierData *)modifiers_findByType(ob, eModifierType_Fluidsim);
-			float active= (float)(fluidmd->fss->flag & OB_FLUIDSIM_ACTIVE);
+			float active= (float) ((fluidmd->fss->flag & OB_FLUIDSIM_ACTIVE) > 0 ? 1 : 0);
 			float rot_d[3] = {0.f, 0.f, 0.f}, old_rot[3] = {0.f, 0.f, 0.f};
 			
 			if (ELEM(fluidmd->fss->type, OB_FLUIDSIM_DOMAIN, OB_FLUIDSIM_PARTICLE))
@@ -467,6 +467,8 @@ static void fluid_init_all_channels(bContext *C, Object *UNUSED(fsDomain), Fluid
 			set_channel(fobj->Scale, timeAtFrame, ob->size, i, CHANNEL_VEC);
 			set_channel(fobj->Active, timeAtFrame, &active, i, CHANNEL_FLOAT);
 			set_channel(fobj->InitialVelocity, timeAtFrame, &fluidmd->fss->iniVelx, i, CHANNEL_VEC);
+
+			// printf("Active: %f, Frame: %f\n", active, timeAtFrame);
 			
 			if (fluidmd->fss->type == OB_FLUIDSIM_CONTROL) {
 				set_channel(fobj->AttractforceStrength, timeAtFrame, &fluidmd->fss->attractforceStrength, i, CHANNEL_FLOAT);
@@ -962,8 +964,8 @@ static int fluidsimBake(bContext *C, ReportList *reports, Object *fsDomain, shor
 	
 	/* ******** prepare output file paths ******** */
 	outStringsChanged = fluid_init_filepaths(fsDomain, targetDir, targetFile, debugStrBuffer);
-	channels->length = scene->r.efra;
-	channels->aniFrameTime = (double)(domainSettings->animEnd - domainSettings->animStart) / (double)noFrames;
+	channels->length = scene->r.efra; // DG TODO: why using endframe and not "noFrames" here? .. because "noFrames" is buggy too? (not using sfra)
+	channels->aniFrameTime = (double)((double)domainSettings->animEnd - (double)domainSettings->animStart) / (double)noFrames;
 	
 	/* ******** initialize and allocate animation channels ******** */
 	fluid_init_all_channels(C, fsDomain, domainSettings, channels, fobjects);

source/blender/modifiers/intern/MOD_fluidsim_util.c

@@ -426,7 +426,11 @@ static DerivedMesh *fluidsim_read_cache(Object *ob, DerivedMesh *orgdm,
                                         FluidsimModifierData *fluidmd, int framenr, int useRenderParams)
 {
 	int displaymode = 0;
-	int curFrame = framenr - 1 /*scene->r.sfra*/; /* start with 0 at start frame */
+	
+	int curFrame = framenr /* - 1 */ /*scene->r.sfra*/; /* start with 0 at start frame */ 
+	/*  why start with 0 as start frame?? Animations + time are frozen for frame 0 anyway. (See physics_fluid.c for that. - DG */
+	/* If we start with frame 0, we need to remap all animation channels, too, because they will all be 1 frame late if using frame-1! - DG */
+
 	char targetFile[FILE_MAX];
 	FluidsimSettings *fss = fluidmd->fss;
 	DerivedMesh *dm = NULL;