Ambiguous cases of mass calculation for surface objects have been more clearly defined

Author: KaiKostack

kk_bullet_constraints_builder.zip

@@ -1899,32 +1899,21 @@ def calculateMass(scene, objs, objsEGrp, childObjs):
 
  ### Calculating and applying material masses based on surface area * thickness
  if (props.surfaceForced and props.surfaceThickness) or (props.surfaceThickness and len(objsNonMan)):
- # Find out density of the element group
- if not materialDensity:
- materialPreset = elemGrp[EGSidxMatP]
- if materialPreset != "":
- try: materialDensity = materialPresets[materialPreset]
- except:
- print("Warning: Density of 0 set and material preset not found for '%s', a density of 1000 kg/m^3 is used." %elemGrp[EGSidxName])
- materialDensity = 1000
- else:
- print("Warning: Density of 0 set and no material preset defined for '%s', a density of 1000 kg/m^3 is used." %elemGrp[EGSidxName])
- materialDensity = 1000
- 
- if props.surfaceForced: objsNonMan = objs
- 
- objsNonManSelected = []
- for n in range(len(objsNonMan)):
- obj = objsNonMan[n]
- k = objsIndex[obj.name]
- if objsEGrp[k] == j: # If object is in current element group
- # Calculate object surface area and volume
- me = obj.data
- area = sum(f.area for f in me.polygons)
- volume = area *props.surfaceThickness
- # Calculate mass
- obj.rigid_body.mass = volume *materialDensity
- objsNonManSelected.append(obj)
+ if materialDensity:
+ if props.surfaceForced: objsNonMan = objs
+
+ objsNonManSelected = []
+ for n in range(len(objsNonMan)):
+ obj = objsNonMan[n]
+ k = objsIndex[obj.name]
+ if objsEGrp[k] == j: # If object is in current element group
+ # Calculate object surface area and volume
+ me = obj.data
+ area = sum(f.area for f in me.polygons)
+ volume = area *props.surfaceThickness
+ # Calculate mass
+ obj.rigid_body.mass = volume *materialDensity
+ objsNonManSelected.append(obj)
 
  ### Adding live load to masses
  liveLoad = elemGrp[EGSidxLoad]
@@ -2034,51 +2023,50 @@ def correctContactAreaByVolume(objs, objsEGrp, connectsPair, connectsGeo):
  try: materialDensity = materialPresets[materialPreset]
  except:
  print("Warning: Density of 0 set and material preset not found for '%s', can't compute mass and leaving it as is." %elemGrp[EGSidxName])
- materialDensity = 1
  else:
  print("Warning: Density of 0 set and no material preset defined for '%s', can't compute mass and leaving it as is." %elemGrp[EGSidxName])
- materialDensity = 1
 
  ### Calculate volumes from densities and derive correctional factors for contact areas
- for k in range(len(objs)):
- if objsEGrp[k] == j: # If object is in current element group
- obj = objs[k]
+ if materialDensity:
+ for k in range(len(objs)):
+ if objsEGrp[k] == j: # If object is in current element group
+ obj = objs[k]
 
- mass = obj.rigid_body.mass
+  mass = obj.rigid_body.mass
 
- ### Remove live load from mass if present
- if liveLoad > 0:
- dims = obj.dimensions
- floorArea = dims[0] *dims[1] # Simple approximation by assuming rectangular floor area (x *y) for live load
- mass -= floorArea *liveLoad
+  ### Remove live load from mass if present
+  if liveLoad > 0:
+  dims = obj.dimensions
+  floorArea = dims[0] *dims[1] # Simple approximation by assuming rectangular floor area (x *y) for live load
+  mass -= floorArea *liveLoad
 
- volume = mass /materialDensity
- 
- ### Find out element thickness to be used for bending threshold calculation 
- dim = obj.dimensions; dimAxis = [1, 2, 3]
- dim, dimAxis = zip(*sorted(zip(dim, dimAxis)))
- dimHeight = dim[0]; dimWidth = dim[1]; dimLength = dim[2]
+  volume = mass /materialDensity
+  
+  ### Find out element thickness to be used for bending threshold calculation 
+  dim = obj.dimensions; dimAxis = [1, 2, 3]
+  dim, dimAxis = zip(*sorted(zip(dim, dimAxis)))
+  dimHeight = dim[0]; dimWidth = dim[1]; dimLength = dim[2]
 
- # Derive contact area correction factor from geometry section area divided by bbox section area
- if dimLength != 0: sectionArea = volume /dimLength # Full geometry section area of element
- else: sectionArea = volume**.5 # Assume cube as fallback if length is zero
+  # Derive contact area correction factor from geometry section area divided by bbox section area
+  if dimLength != 0: sectionArea = volume /dimLength # Full geometry section area of element
+  else: sectionArea = volume**.5 # Assume cube as fallback if length is zero
 
- ### Compensate section area for rescaling
- try: scale = elemGrp[EGSidxScal] # Try in case elemGrps is from an old BCB version
- except: pass
- else:
- if obj != None and scale != 0 and scale != 1:
- sectionArea *= scale**3 # Cubic instead of square because dimLength is included as well
+  ### Compensate section area for rescaling
+  try: scale = elemGrp[EGSidxScal] # Try in case elemGrps is from an old BCB version
+  except: pass
+  else:
+  if obj != None and scale != 0 and scale != 1:
+  sectionArea *= scale**3 # Cubic instead of square because dimLength is included as well
 
- ### Determine contact area correction factor
- if dimHeight *dimWidth != 0 and mass != materialDensity: # Special case: mass = materialDensity only for foundation elements
- corFac = sectionArea / (dimHeight *dimWidth)
- else: corFac = 1
+  ### Determine contact area correction factor
+  if dimHeight *dimWidth != 0 and mass != materialDensity: # Special case: mass = materialDensity only for foundation elements
+  corFac = sectionArea / (dimHeight *dimWidth)
+  else: corFac = 1
 
- obj["CA Corr.Fac."] = corFac
- obj["Density"] = materialDensity
- obj["Volume"] = volume
-  
+  obj["CA Corr.Fac."] = corFac
+  obj["Density"] = materialDensity
+  obj["Volume"] = volume
+ 
 ################################################################################ 
 
 def generateDetonator(objs, connectsPair, objsEGrp):

kk_bullet_constraints_builder/builder_prep.py

@@ -213,9 +213,11 @@ def setConstraintSettings(objs, objsEGrp, emptyObjs, objsID, connectsPair, conne
  ### Apply corrections to geometry lists 
  qVolCorrect = geo[6]
 
- if qVolCorrect: # No correction needed in valid polygon based contact area cases 
- corFacA = objA["CA Corr.Fac."]
- corFacB = objB["CA Corr.Fac."]
+ if qVolCorrect: # No correction needed in valid polygon based contact area cases
+ try: corFacA = objA["CA Corr.Fac."]
+ except: corFacA = 1
+ try: corFacB = objB["CA Corr.Fac."]
+ except: corFacB = 1
  geoContactArea *= min(corFacA, corFacB)
 
  ### Prepare connection data