adds an ejectionOffsetVariance entry to particle emitters, which adds a buffer zone to ejectionOffsets (IE: let's us make rings, and the like.)

Engine/source/T3D/fx/particleEmitter.cpp

@@ -118,6 +118,7 @@ ParticleEmitterData::ParticleEmitterData()
    ejectionVelocity = 2.0f;   // From 1.0 - 3.0 meters per sec
    velocityVariance = 1.0f;
    ejectionOffset   = sgDefaultEjectionOffset;   // ejection from the emitter point
+   ejectionOffsetVariance = 0.0f;
 
    thetaMin         = 0.0f;   // All heights
    thetaMax         = 90.0f;
@@ -199,6 +200,9 @@ void ParticleEmitterData::initPersistFields()
 
       addFieldV( "ejectionOffset", TYPEID< F32 >(), Offset(ejectionOffset, ParticleEmitterData), &ejectionFValidator,
          "Distance along ejection Z axis from which to eject particles." );
+		 
+      addFieldV( "ejectionOffsetVariance", TYPEID< F32 >(), Offset(ejectionOffsetVariance, ParticleEmitterData), &ejectionFValidator,
+         "Distance Padding along ejection Z axis from which to eject particles." );
 
       addFieldV( "thetaMin", TYPEID< F32 >(), Offset(thetaMin, ParticleEmitterData), &thetaFValidator,
          "Minimum angle, from the horizontal plane, to eject from." );
@@ -316,6 +320,8 @@ void ParticleEmitterData::packData(BitStream* stream)
    stream->writeInt((S32)(velocityVariance * 100), 14);
    if( stream->writeFlag( ejectionOffset != sgDefaultEjectionOffset ) )
       stream->writeInt((S32)(ejectionOffset * 100), 16);
+   if( stream->writeFlag( ejectionOffsetVariance != 0.0f ) )
+      stream->writeInt((S32)(ejectionOffsetVariance * 100), 16);
    stream->writeRangedU32((U32)thetaMin, 0, 180);
    stream->writeRangedU32((U32)thetaMax, 0, 180);
    if( stream->writeFlag( phiReferenceVel != sgDefaultPhiReferenceVel ) )
@@ -368,7 +374,10 @@ void ParticleEmitterData::unpackData(BitStream* stream)
       ejectionOffset = stream->readInt(16) / 100.0f;
    else
       ejectionOffset = sgDefaultEjectionOffset;
-
+   if( stream->readFlag() )
+      ejectionOffsetVariance = stream->readInt(16) / 100.0f;
+   else
+      ejectionOffsetVariance = 0.0f;
    thetaMin = (F32)stream->readRangedU32(0, 180);
    thetaMax = (F32)stream->readRangedU32(0, 180);
    if( stream->readFlag() )
@@ -1287,7 +1296,7 @@ void ParticleEmitter::addParticle(const Point3F& pos,
    F32 initialVel = mDataBlock->ejectionVelocity;
    initialVel    += (mDataBlock->velocityVariance * 2.0f * gRandGen.randF()) - mDataBlock->velocityVariance;
 
-   pNew->pos = pos + (ejectionAxis * mDataBlock->ejectionOffset);
+   pNew->pos = pos_start + (ejectionAxis * (mDataBlock->ejectionOffset + mDataBlock->ejectionOffsetVariance* gRandGen.randF()) );
    pNew->vel = ejectionAxis * initialVel;
    pNew->orientDir = ejectionAxis;
    pNew->acc.set(0, 0, 0);

Engine/source/T3D/fx/particleEmitter.h

@@ -73,7 +73,7 @@ class ParticleEmitterData : public GameBaseData
    F32   ejectionVelocity;                   ///< Ejection velocity
    F32   velocityVariance;                   ///< Variance for velocity between 0 and n
    F32   ejectionOffset;                     ///< Z offset from emitter point to eject from
-
+   F32   ejectionOffsetVariance;             ///< Z offset Variance from emitter point to eject 
    F32   thetaMin;                           ///< Minimum angle, from the horizontal plane, to eject from
    F32   thetaMax;                           ///< Maximum angle, from the horizontal plane, to eject from
 

Templates/Empty/game/tools/particleEditor/ParticleEditor.ed.gui

@@ -1069,7 +1069,53 @@ $PE_guielement_ext_colorpicker = "18 18";
                            position = $PE_guielement_pos_value;
                            Extent = $PE_guielement_ext_value;
                            altCommand = "$ThisControl.getParent().updateFromChild($ThisControl); PE_EmitterEditor.updateEmitter( \"ejectionOffset\", $ThisControl.getText());";
-                        };             
+                        };
+					 };
+                     new GuiControl(){ // Emitter Offset Variance
+                        class = "AggregateControl";
+                        isContainer = "1";
+                        HorizSizing = "width";
+                        VertSizing = "bottom";
+                        Position = $PE_guielement_pos_single_container ;
+                        Extent = $PE_guielement_ext_single_container ;
+                        
+                        new GuiTextCtrl() {
+                           Profile = "ToolsGuiTextProfile";
+                           HorizSizing = "width";
+                           VertSizing = "bottom";
+                           position = $PE_guielement_pos_name;
+                           Extent = $PE_guielement_ext_name;
+                           text = "OffsetVariance";
+                        };
+                        new GuiSliderCtrl(PEE_ejectionOffsetVariance) {
+                           internalName = "PEE_ejectionOffsetVariance_slider";
+                           canSaveDynamicFields = "0";
+                           Enabled = "1";
+                           isContainer = "0";
+                           Profile = "ToolsGuiSliderProfile";
+                           HorizSizing = "left";
+                           VertSizing = "bottom";
+                           position = $PE_guielement_pos_slider;
+                           Extent = $PE_guielement_ext_slider;
+                           MinExtent = "8 2";
+                           canSave = "1";
+                           Visible = "1";
+                           Command = "PE_EmitterEditor.updateEmitter( \"ejectionOffsetVariance\", $ThisControl.getValue(), true, true );";
+                           altCommand = "$ThisControl.getParent().updateFromChild($ThisControl); PE_EmitterEditor.updateEmitter( \"ejectionOffsetVariance\", $ThisControl.getValue(), true, false );";
+                           hovertime = "1000";
+                           range = "0 25";
+                           ticks = "0";
+                           value = "0";
+                        };
+                        new GuiTextEditCtrl() {
+                           internalName = "PEE_ejectionOffsetVariance_textEdit";
+                           Profile = "ToolsGuiTextEditProfile";
+                           HorizSizing = "left";
+                           VertSizing = "bottom";
+                           position = $PE_guielement_pos_value;
+                           Extent = $PE_guielement_ext_value;
+                           altCommand = "$ThisControl.getParent().updateFromChild($ThisControl); PE_EmitterEditor.updateEmitter( \"ejectionOffsetVariance\", $ThisControl.getText());";
+                        };               
                      };
                   }; // end stack
                }; // end "spread" rollout

Templates/Full/game/tools/particleEditor/ParticleEditor.ed.gui

@@ -1069,7 +1069,53 @@ $PE_guielement_ext_colorpicker = "18 18";
                            position = $PE_guielement_pos_value;
                            Extent = $PE_guielement_ext_value;
                            altCommand = "$ThisControl.getParent().updateFromChild($ThisControl); PE_EmitterEditor.updateEmitter( \"ejectionOffset\", $ThisControl.getText());";
-                        };             
+                        };
+					 };
+                     new GuiControl(){ // Emitter Offset Variance
+                        class = "AggregateControl";
+                        isContainer = "1";
+                        HorizSizing = "width";
+                        VertSizing = "bottom";
+                        Position = $PE_guielement_pos_single_container ;
+                        Extent = $PE_guielement_ext_single_container ;
+                        
+                        new GuiTextCtrl() {
+                           Profile = "ToolsGuiTextProfile";
+                           HorizSizing = "width";
+                           VertSizing = "bottom";
+                           position = $PE_guielement_pos_name;
+                           Extent = $PE_guielement_ext_name;
+                           text = "OffsetVariance";
+                        };
+                        new GuiSliderCtrl(PEE_ejectionOffsetVariance) {
+                           internalName = "PEE_ejectionOffsetVariance_slider";
+                           canSaveDynamicFields = "0";
+                           Enabled = "1";
+                           isContainer = "0";
+                           Profile = "ToolsGuiSliderProfile";
+                           HorizSizing = "left";
+                           VertSizing = "bottom";
+                           position = $PE_guielement_pos_slider;
+                           Extent = $PE_guielement_ext_slider;
+                           MinExtent = "8 2";
+                           canSave = "1";
+                           Visible = "1";
+                           Command = "PE_EmitterEditor.updateEmitter( \"ejectionOffsetVariance\", $ThisControl.getValue(), true, true );";
+                           altCommand = "$ThisControl.getParent().updateFromChild($ThisControl); PE_EmitterEditor.updateEmitter( \"ejectionOffsetVariance\", $ThisControl.getValue(), true, false );";
+                           hovertime = "1000";
+                           range = "0 25";
+                           ticks = "0";
+                           value = "0";
+                        };
+                        new GuiTextEditCtrl() {
+                           internalName = "PEE_ejectionOffsetVariance_textEdit";
+                           Profile = "ToolsGuiTextEditProfile";
+                           HorizSizing = "left";
+                           VertSizing = "bottom";
+                           position = $PE_guielement_pos_value;
+                           Extent = $PE_guielement_ext_value;
+                           altCommand = "$ThisControl.getParent().updateFromChild($ThisControl); PE_EmitterEditor.updateEmitter( \"ejectionOffsetVariance\", $ThisControl.getText());";
+                        };               
                      };
                   }; // end stack
                }; // end "spread" rollout