Patch #8882 - Falloff in the wave modifier

This patch adds the ability to specify a falloff radius in the Wave modifier.
Currently only linear falloff is supported.

Thanks to Michael Fox for the patch!

source/blender/blenkernel/intern/modifier.c

@@ -4541,6 +4541,7 @@ static void waveModifier_initData(ModifierData *md)
 	wmd->narrow= 1.5f;
 	wmd->lifetime= 0.0f;
 	wmd->damp= 10.0f;
+	wmd->falloff= 0.0f;
 	wmd->texmapping = MOD_WAV_MAP_LOCAL;
 	wmd->defgrp_name[0] = 0;
 }
@@ -4560,6 +4561,7 @@ static void waveModifier_copyData(ModifierData *md, ModifierData *target)
 	twmd->starty = wmd->starty;
 	twmd->timeoffs = wmd->timeoffs;
 	twmd->width = wmd->width;
+	twmd->falloff = wmd->falloff;
 	twmd->objectcenter = wmd->objectcenter;
 	twmd->texture = wmd->texture;
 	twmd->map_object = wmd->map_object;
@@ -4791,6 +4793,8 @@ static void waveModifier_do(
 			float x = co[0] - wmd->startx;
 			float y = co[1] - wmd->starty;
 			float amplit= 0.0f;
+			float dist = 0.0f;
+			float falloff_fac = 0.0f;
 			TexResult texres;
 			MDeformWeight *def_weight = NULL;
 
@@ -4813,6 +4817,21 @@ static void waveModifier_do(
 				get_texture_value(wmd->texture, tex_co[i], &texres);
 			}
 
+			/*get dist*/
+			if(wmd->flag & MOD_WAVE_X) {
+				if(wmd->flag & MOD_WAVE_Y){
+					dist = (float)sqrt(x*x + y*y);
+				}
+				else{
+					dist = fabs(x);
+				}
+			}
+			else if(wmd->flag & MOD_WAVE_Y) {
+				dist = fabs(y);
+			}
+
+			falloff_fac = (1.0-(dist / wmd->falloff));
+			CLAMP(falloff_fac,0,1);
 
 			if(wmd->flag & MOD_WAVE_X) {
 				if(wmd->flag & MOD_WAVE_Y) amplit = (float)sqrt(x*x + y*y);
@@ -4833,12 +4852,19 @@ static void waveModifier_do(
 			if(amplit > -wmd->width && amplit < wmd->width) {
 				amplit = amplit * wmd->narrow;
 				amplit = (float)(1.0 / exp(amplit * amplit) - minfac);
+
+				/*apply texture*/
 				if(wmd->texture)
 					amplit = amplit * texres.tin;
 
+				/*apply weight*/
 				if(def_weight)
 					amplit = amplit * def_weight->weight;
 
+				/*apply falloff*/
+				if (wmd->falloff > 0)
+					amplit = amplit * falloff_fac;
+
 				if(mvert) {
 					/* move along normals */
 					if(wmd->flag & MOD_WAVE_NORM_X) {

source/blender/makesdna/DNA_modifier_types.h

@@ -329,13 +329,14 @@ typedef struct WaveModifierData {
 	short flag, pad;
 
 	float startx, starty, height, width;
-	float narrow, speed, damp;
+	float narrow, speed, damp, falloff;
 
 	int texmapping, uvlayer_tmp;
 
 	char uvlayer_name[32];
 
 	float timeoffs, lifetime;
+	float pad1;
 } WaveModifierData;
 
 typedef struct ArmatureModifierData {

source/blender/src/buttons_editing.c

@@ -1792,7 +1792,7 @@ static void draw_modifier(uiBlock *block, Object *ob, ModifierData *md, int *xco
 			height = 143;
 		} else if (md->type==eModifierType_Wave) {
 			WaveModifierData *wmd = (WaveModifierData *)md;
-			height = 294;
+			height = 315;
 			if(wmd->texmapping == MOD_WAV_MAP_OBJECT ||
 			   wmd->texmapping == MOD_WAV_MAP_UV)
 				height += 19;
@@ -2154,6 +2154,8 @@ static void draw_modifier(uiBlock *block, Object *ob, ModifierData *md, int *xco
 				uiDefButF(block, NUM, B_MODIFIER_RECALC, "Time end:",	lx,(cy-=19),buttonWidth,19, &wmd->timeoffs, -MAXFRAMEF, MAXFRAMEF, 100, 0, "Specify ending frame of the wave");
 			uiDefButF(block, NUM, B_MODIFIER_RECALC, "Lifetime:",	lx,(cy-=19),buttonWidth,19, &wmd->lifetime,  -MAXFRAMEF, MAXFRAMEF, 100, 0, "Specify the lifespan of the wave");
 			uiDefButF(block, NUM, B_MODIFIER_RECALC, "Damptime:",	lx,(cy-=19),buttonWidth,19, &wmd->damp,  -MAXFRAMEF, MAXFRAMEF, 100, 0, "Specify the dampingtime of the wave");
+			uiDefButF(block, NUM, B_MODIFIER_RECALC, "Falloff:",	lx,(cy-=19),buttonWidth,19, &wmd->falloff,  0, 100, 100, 0, "Specify the falloff radius of the waves");
+
 			cy -= 9;
 			uiBlockBeginAlign(block);
 			uiDefButF(block, NUM, B_MODIFIER_RECALC, "Sta x:",		lx,(cy-=19),113,19, &wmd->startx, -100.0, 100.0, 100, 0, "Starting position for the X axis");