- It is possible to scale radius of MetaElem again.

- It is possible to change dx, dy and dz params in 3Dview with manipulators
    or with some shortcuts (S-X, S-Y, S-Z).
 - User can scale stiffness when green circle is selected.
 - MetaElem is selected with RMB click at green or red circle, then user can
    grab or rotate with MetaElem as usual.

 - Screenshot:
    http://e-learning.vslib.cz/~hnidek/pics/scale_stiffness.jpg

 - Captured video:
    http://e-learning.vslib.cz/~hnidek/captured-videos/scale_stiffness.avi

source/blender/include/transform.h

@@ -198,6 +198,7 @@ typedef struct TransInfo {
 #define	TD_NOACTION		2
 #define	TD_USEQUAT		4
 #define TD_NOTCONNECTED		8
+#define TD_SINGLESIZE		16	/* used for scaling of MetaElem->rad */
 
 void initWarp(TransInfo *t);
 int Warp(TransInfo *t, short mval[2]);

source/blender/makesdna/DNA_meta_types.h

@@ -48,7 +48,7 @@ typedef struct MetaElem {
 	struct BoundBox *bb;		/* Bound Box of MetaElem */
 	int i1,j1,k1, i2,j2,k2;		/* corners of Bounding Box in lattice */
 
-	short type, lay, flag, selcol;
+	short type, flag, selcol1, selcol2;
 	float x, y, z;			/* Position of centre of MetaElem */
 	float quat[4];			/* Rotation of MetaElem */
 	float expx, expy, expz;		/* dx, dy, dz parameters */
@@ -104,6 +104,7 @@ typedef struct MetaBall {
 /* ml->flag */
 #define MB_NEGATIVE	2
 #define MB_HIDE		8
+#define MB_SCALE_RAD	16
 
 #endif
 

source/blender/python/api2_2x/Metaball.c

@@ -410,7 +410,7 @@ static PyObject *Metaball_addMetaelem( BPy_Metaball * self, PyObject * args )
 {
 	MetaElem *ml;
 	PyObject *listargs = 0;
-	int type, lay;
+	int type;
 	float x, y, z, rad, s, expx, expy, expz;
 	if( !PyArg_ParseTuple( args, "O", &listargs ) )
 		return ( EXPP_ReturnPyObjError
@@ -425,7 +425,6 @@ static PyObject *Metaball_addMetaelem( BPy_Metaball * self, PyObject * args )
 	y = PyFloat_AsDouble( PyList_GetItem( listargs, 2 ) );
 	z = PyFloat_AsDouble( PyList_GetItem( listargs, 3 ) );
 	rad = PyFloat_AsDouble( PyList_GetItem( listargs, 4 ) );
-	lay = PyInt_AsLong( PyList_GetItem( listargs, 5 ) );
 	s = PyFloat_AsDouble( PyList_GetItem( listargs, 6 ) );
 	expx = PyFloat_AsDouble( PyList_GetItem( listargs, 7 ) );
 	expy = PyFloat_AsDouble( PyList_GetItem( listargs, 8 ) );
@@ -438,7 +437,6 @@ static PyObject *Metaball_addMetaelem( BPy_Metaball * self, PyObject * args )
 	ml->y = y;
 	ml->z = z;
 	ml->rad = rad;
-	ml->lay = lay;
 	ml->s = s;
 	ml->flag = SELECT;
 	ml->type = type;

source/blender/src/drawobject.c

@@ -2980,17 +2980,30 @@ static void drawmball(Object *ob, int dt)
 	
 	while(ml) {
 	
+		/* draw radius */
 		if(ob==G.obedit) {
-			if(ml->flag & SELECT) cpack(0xA0A0F0);
+			if((ml->flag & SELECT) && (ml->flag & MB_SCALE_RAD)) cpack(0xA0A0F0);
 			else cpack(0x3030A0);
 			
 			if(G.f & G_PICKSEL) {
-				ml->selcol= code;
+				ml->selcol1= code;
 				glLoadName(code++);
 			}
 		}
 		drawcircball(&(ml->x), ml->rad, imat);
 
+		/* draw stiffness */
+		if(ob==G.obedit) {
+			if((ml->flag & SELECT) && !(ml->flag & MB_SCALE_RAD)) cpack(0xA0F0A0);
+			else cpack(0x30A030);
+			
+			if(G.f & G_PICKSEL) {
+				ml->selcol2= code;
+				glLoadName(code++);
+			}
+		}
+		drawcircball(&(ml->x), ml->rad*atan(ml->s)/M_PI_2, imat);
+		
 		ml= ml->next;
 	}
 }

source/blender/src/editmball.c

@@ -177,9 +177,8 @@ void add_primitiveMball(int dummy_argument)
 	ml->quat[2]= 0.0;
 	ml->quat[3]= 0.0;
 	ml->rad= 2.0;
-	ml->lay= 1;
 	ml->s= 2.0;
-	ml->flag= SELECT;
+	ml->flag= SELECT | MB_SCALE_RAD;
 
         switch(dummy_argument) {
                 case 1:
@@ -258,13 +257,19 @@ void mouse_mball()
 	if(hits>0) {
 		ml= startelem;
 		while(ml) {
-			/* if(base->lay & G.vd->lay) { */
 			
 			for(a=0; a<hits; a++) {
 				/* index converted for gl stuff */
-					if(ml->selcol==buffer[ 4 * a + 3 ]) act= ml;
+				if(ml->selcol1==buffer[ 4 * a + 3 ]){
+					ml->flag |= MB_SCALE_RAD;
+					act= ml;
+				}
+				if(ml->selcol2==buffer[ 4 * a + 3 ]){
+					ml->flag &= ~MB_SCALE_RAD;
+					act= ml;
+				}
+
 			}
-			/* } */
 			
 			if(act) break;
 			

source/blender/src/editview.c

@@ -1400,7 +1400,14 @@ void borderselect(void)
 				
 				while(ml) {
 					for(a=0; a<hits; a++) {
-						if(ml->selcol==buffer[ (4 * a) + 3 ]) {
+						if(ml->selcol1==buffer[ (4 * a) + 3 ]) {
+							ml->flag |= MB_SCALE_RAD;
+							if(val==LEFTMOUSE) ml->flag |= SELECT;
+							else ml->flag &= ~SELECT;
+							break;
+						}
+						if(ml->selcol2==buffer[ (4 * a) + 3 ]) {
+							ml->flag &= ~MB_SCALE_RAD;
 							if(val==LEFTMOUSE) ml->flag |= SELECT;
 							else ml->flag &= ~SELECT;
 							break;

source/blender/src/transform.c

@@ -1021,6 +1021,9 @@ int Resize(TransInfo *t, short mval[2])
 					add_tdi_poin(tdi->sizez, tdi->oldsize+2, vec[2]);
 					
 				}
+				else if((td->flag & TD_SINGLESIZE) && !(t->con.mode & CON_APPLY)){
+ 					*td->val = td->ival * fsize[0] * td->factor;
+ 				}	
 				else {
 					td->ext->size[0] = td->ext->isize[0] * (fsize[0]) * td->factor;
 					td->ext->size[1] = td->ext->isize[1] * (fsize[1]) * td->factor;

source/blender/src/transform_conversions.c

@@ -591,7 +591,7 @@ static void createTransMBallVerts(TransInfo *t)
 			VECCOPY(td->iloc, td->loc);
 			VECCOPY(td->center, td->loc);
 
-			if(ml->flag & SELECT) td->flag= TD_SELECTED | TD_USEQUAT;
+			if(ml->flag & SELECT) td->flag= TD_SELECTED | TD_USEQUAT | TD_SINGLESIZE;
 			else td->flag= TD_USEQUAT;
 
 			Mat3CpyMat3(td->smtx, smtx);
@@ -599,13 +599,24 @@ static void createTransMBallVerts(TransInfo *t)
 
 			td->ext = tx;
 			td->tdi = NULL;
-			td->val = NULL;
 
+			/* Radius of MetaElem (mass of MetaElem influence) */
+			if(ml->flag & MB_SCALE_RAD){
+				td->val = &ml->rad;
+				td->ival = ml->rad;
+			}
+			else{
+				td->val = &ml->s;
+				td->ival = ml->s;
+			}
+
+			/* expx/expy/expz determine "shape" of some MetaElem types */
 			tx->size = &ml->expx;
 			tx->isize[0] = ml->expx;
 			tx->isize[1] = ml->expy;
 			tx->isize[2] = ml->expz;
 
+			/* quat is used for rotation of MetaElem */
 			tx->quat = ml->quat;
 			QUATCOPY(tx->iquat, ml->quat);