Plumiferos request (and useful :)

Static particle option: maximum length. Button is next to "Vect" in first
particle panel. This allows weird forcefields and wind to act without
extreme long strands.

3 files changed, 13 insertions, 3 deletions

diff --git a/source/blender/blenkernel/intern/effect.c b/source/blender/blenkernel/intern/effect.c
index 102bc479bed..ad3e2008b9f 100644
--- a/source/blender/blenkernel/intern/effect.c
+++ b/source/blender/blenkernel/intern/effect.c
@@ -1017,7 +1017,7 @@ static void make_particle_keys(RNG *rng, Object *ob, int depth, int nr, PartEff
 {
 	Particle *pa, *opa = NULL;
 	float damp, deltalife, life;
-	float cur_time;
+	float cur_time, maxspeed= paf->maxlen/(float)paf->totkey;
 	float opco[3], opno[3], npco[3], npno[3], new_force[3], new_speed[3];
 	int b, rt1, rt2, deflected, deflection, finish_defs, def_count;
 	int last_ob, last_fc, same_fc;
@@ -1100,6 +1100,13 @@ static void make_particle_keys(RNG *rng, Object *ob, int depth, int nr, PartEff
 		pa->no[1]= deltalife * (new_speed[1] + new_force[1]);
 		pa->no[2]= deltalife * (new_speed[2] + new_force[2]);
 		
+		/* speed limitor */
+		if((paf->flag & PAF_STATIC) && maxspeed!=0.0f) {
+			float len= VecLength(pa->no);
+			if(len > maxspeed)
+				VecMulf(pa->no, maxspeed/len);
+		}
+			
 		/* new location */
 		pa->co[0]= opa->co[0] + pa->no[0];
 		pa->co[1]= opa->co[1] + pa->no[1];
diff --git a/source/blender/makesdna/DNA_effect_types.h b/source/blender/makesdna/DNA_effect_types.h
index 571f87ae33f..435a18e5ab2 100644
--- a/source/blender/makesdna/DNA_effect_types.h
+++ b/source/blender/makesdna/DNA_effect_types.h
@@ -117,7 +117,7 @@ typedef struct PartEff {
 	float force[3];
 	float damp;
 	
-	float nabla, vectsize, defvec[3];
+	float nabla, vectsize, maxlen, pad, defvec[3];
 	
 	float mult[4], life[4];
 	short child[4], mat[4];
diff --git a/source/blender/src/buttons_object.c b/source/blender/src/buttons_object.c
index 1fdbfab4642..76c98056072 100644
--- a/source/blender/src/buttons_object.c
+++ b/source/blender/src/buttons_object.c
@@ -2616,7 +2616,10 @@ static void object_panel_particles(Object *ob)
 	uiDefButBitS(block, TOG, PAF_UNBORN, B_DIFF, "Unborn",210,110,50,20, &paf->flag, 0, 0, 0, 0, "Make particles appear before they are emitted");
 	uiDefButBitS(block, TOG, PAF_DIED, B_DIFF, "Died",	260,110,50,20, &paf->flag, 0, 0, 0, 0, "Make particles appear after they have died");
 	uiDefButS(block, TOG, REDRAWVIEW3D, "Vect",			160,90,75,20, &paf->stype, 0, 0, 0, 0, "Give the particles a direction and rotation");
-	uiDefButF(block, NUM, B_DIFF,		"Size:",		235,90,75,20, &paf->vectsize, 0.0, 1.0, 10, 1, "The amount the Vect option influences halo size");	
+	if(paf->flag & PAF_STATIC) 
+		uiDefButF(block, NUM, B_CALCEFFECT,	 "Max:",	235,90,75,20, &paf->maxlen, 0.0, 100.0, 10, 1, "The maximum length of a particle strand (zero is no limit)");
+	else
+		uiDefButF(block, NUM, B_CALCEFFECT,	 "Size:",	235,90,75,20, &paf->vectsize, 0.0, 1.0, 10, 1, "The amount the Vect option influences halo size");	
 	uiBlockEndAlign(block);
 
 	uiDefBut(block, LABEL, 0, "Children:",				160,70,75,20, NULL, 0.0, 0, 0, 0, "");