diff -urN wf-/data.c wf/data.c
--- wf-/data.c	2015-12-21 00:00:00.000000000 +0900
+++ wf/data.c	2015-12-24 00:00:00.000000000 +0900
@@ -23,6 +23,7 @@
 	CASE_RET(type_point_symmetry);
 	CASE_RET(type_mirror);
 	CASE_RET(type_timeshift);
+	CASE_RET(type_rdiv);
 	CASE_RET(type_slide_way);
 	CASE_RET(type_rot_way);
 	CASE_RET(type_copy);
@@ -43,27 +44,112 @@
 	eye_update(eye);
 	prm->eye = eye;
 	affin_axis_conv(&prm->af, &eye->ax);
+	prm->sec = eye->sec;
+	prm->rdiv = NULL;
+	prm->skip_af = 0;
 }
 
 static void
-wire_frame_draw(struct wire_frame *wf, prm_t *prm)
+wf_calc_v_len(struct wire_frame *wf)
 {
 	int i, *op = wf->odr;
 
-	if(!wf->t){
-		if((wf->t = malloc(sizeof(*wf->t) * wf->n)) == NULL) ERR("No Mem");
+
+	for(i=0; i<wf->n; i++){
+		d3_set(&wf->v[i], 0,0,0);
+	}
+
+	wf->sum_len = 0;
+	wf->line_n = 0;
+	while(op[0] >= 0 && op[1] >= 0){
+		vec_t v;
+		double len;
+
+		vec_set(&v, &wf->t[ op[0] ], &wf->t[ op[1] ]);
+		if((len = vec_len(&v)) == 0) ERR("vec_len() == 0");
+		wf->sum_len += len;
+		wf->line_n++;
+
+		vec_unit(&v);
+		d3_mul(&v, 1/len);
+		d3_add(&wf->v[ op[1] ], &v);
+		d3_sub(&wf->v[ op[0] ], &v);
+
+		op++;
+		if(op[1] < 0) op += 2;
 	}
 
 	for(i=0; i<wf->n; i++){
-		wf->t[i] = wf->p[i];
-		affin_conv(&prm->af, &wf->t[i]);
+		vec_unit(&wf->v[i]);
 	}
+}
+
+static void
+wf_rdiv_draw(struct wire_frame *wf, prm_t *prm, int op0, int op1)
+{
+	prm_t bak = *prm;
+	const struct rdiv *rdiv = prm->rdiv;
+	pos_t *p2[2] = { &wf->t[ op0 ], &wf->t[ op1 ] };
+	double len = pos_distance(p2[0], p2[1]);
+	int i, n = 2 + (int)(rdiv->n * len * wf->line_n / wf->sum_len);
+	d3_t np[256 * 3];
+	int nodr[256 + 2];
+	struct wire_frame nwf = { n, np, nodr, &np[n], &np[n*2] };
+	data_t data = { type_wire_frame, &nwf };
+	vec_t v, v2[2];
+	line_t l;
+	double deg;
+
+	if(n > 256) ERR("n>256");
+
+	vec_set(&v, p2[0], p2[1]);
+	vec_arot(&wf->v[op1], &v, &l, &deg);
+	deg = (deg < 180 ? 90 : 90*3) - deg;
+	pos_rot(&v, &l, deg * rdiv->rate);
+	v2[1] = v;
+
+	vec_set(&v, p2[1], p2[0]);
+	vec_arot(&wf->v[op0], &v, &l, &deg);
+	deg = (deg < 180 ? 90 : 90*3) - deg;
+	pos_rot(&v, &l, deg * rdiv->rate);
+	d3_mul(&v, -1);
+	v2[0] = v;
+
+	for(i=0; i<n; i++){
+		interp3_pos(p2[0], p2[1], &v2[0], &v2[1], (double)i/(n-1), &nwf.t[i]);
+		nwf.odr[i] = i;
+	}
+	nwf.odr[n] = nwf.odr[n+1] = -1;
+
+	prm->rdiv = NULL;
+	prm->skip_af = 1;
+	data_draw(&data, prm);
+	*prm = bak;
+}
+
+static void
+wire_frame_draw(struct wire_frame *wf, prm_t *prm)
+{
+	int i, *op = wf->odr;
+
+	if(!wf->t) ERR("wf->t NULL");
+
+	if(!prm->skip_af){
+		for(i=0; i<wf->n; i++){
+			wf->t[i] = wf->p[i];
+			affin_conv(&prm->af, &wf->t[i]);
+		}
+	}
+
+	if(prm->rdiv) wf_calc_v_len(wf);
 
 	while(op[0] >= 0 && op[1] >= 0){
 		pos_t p2[2];
 		p2[0] = wf->t[ op[0] ];
 		p2[1] = wf->t[ op[1] ];
-		if(eye_clip(prm->eye, &p2[0], &p2[1]) >= 0){
+		if(prm->rdiv){
+			wf_rdiv_draw(wf, prm, op[0], op[1]);
+		}else if(eye_clip(prm->eye, &p2[0], &p2[1]) >= 0){
 			int x[2], y[2];
 			eye_conv(prm->eye, &p2[0], &x[0], &y[0]);
 			eye_conv(prm->eye, &p2[1], &x[1], &y[1]);
@@ -79,10 +165,10 @@
 static void
 bar_draw(pos_t *p2, prm_t *prm)
 {
-	pos_t wk[2];
+	d3_t wk[2*2];
 	data_t data = {
 		type_wire_frame,
-		&(struct wire_frame){ 2, p2, (int[]){ 0,1,-1, -1 }, wk }
+		&(struct wire_frame){ 2, p2, (int[]){ 0,1,-1, -1 }, wk, &wk[2] }
 	};
 	data_draw(&data, prm);
 }
@@ -110,13 +196,13 @@
 static void
 square_draw(prm_t *prm)
 {
-	pos_t wk[4];
+	pos_t wk[4*2];
 	data_t data = {
 		type_wire_frame,
 		&(struct wire_frame){
 			4,
 			(pos_t[]){ {-1,-1,0},{1,-1,0},{1,1,0},{-1,1,0} },
-			(int[]){ 0,1,2,3,0,-1, -1 }, wk }
+			(int[]){ 0,1,2,3,0,-1, -1 }, wk, &wk[4] }
 	};
 	data_draw(&data, prm);
 }
@@ -124,7 +210,7 @@
 static void
 cube_draw(prm_t *prm)
 {
-	pos_t wk[8];
+	pos_t wk[8*2];
 	data_t data = {
 		type_wire_frame,
 		&(struct wire_frame){
@@ -134,7 +220,7 @@
 				{-1,-1,1},{1,-1,1},{1,1,1},{-1,1,1} },
 			(int[]){
 				0,1,2,3,0,-1, 4,5,6,7,4,-1,
-				0,4,-1, 1,5,-1, 2,6,-1, 3,7,-1, -1 }, wk }
+				0,4,-1, 1,5,-1, 2,6,-1, 3,7,-1, -1 }, wk, &wk[8] }
 	};
 	data_draw(&data, prm);
 }
@@ -264,6 +350,13 @@
 }
 
 static void
+op_data_rdiv(struct rdiv *rdiv, data_t *data, prm_t *prm)
+{
+	prm->rdiv = rdiv;
+	data_draw(data, prm);
+}
+
+static void
 op_data_slide_way(struct way *slide, data_t *data, prm_t *prm)
 {
 	struct way way = *slide;	
@@ -288,6 +381,18 @@
 }
 
 static void
+op_data_rdiv_way(struct rdiv_way *rdw, data_t *data, prm_t *prm)
+{
+	struct way way = rdw->rate_way;
+	struct rdiv rdiv = { .n=rdw->n };
+	data_t op = { type_rdiv, &rdiv };
+
+	way_get(&way, prm->sec);
+	rdiv.rate = way.ret_v;
+	op_data_draw(&op, data, prm);
+}
+
+static void
 op_data_copy(struct copy *copy, data_t *data, prm_t *prm)
 {
 	int x, y, z;
@@ -384,6 +489,9 @@
 	case type_timeshift:
 		op_data_timeshift(op->p, data, prm);
 		break;
+	case type_rdiv:
+		op_data_rdiv(op->p, data, prm);
+		break;
 
 	case type_slide_way:
 		op_data_slide_way(op->p, data, prm);
@@ -391,6 +499,9 @@
 	case type_rot_way:
 		op_data_rot_way(op->p, data, prm);
 		break;
+	case type_rdiv_way:
+		op_data_rdiv_way(op->p, data, prm);
+		break;
 
 	case type_copy:
 		op_data_copy(op->p, data, prm);
@@ -414,3 +525,14 @@
 	}
 	*prm = bak;
 }
+
+void
+wf_init_work_alloc(struct wire_frame *wf, d3_t *t_and_v)
+{
+	if(t_and_v){
+		wf->t = t_and_v;
+	}else{
+		if((wf->t = malloc(sizeof(d3_t) * wf->n * 2)) == NULL) ERR("No Mem");
+	}
+	wf->v = &wf->t[ wf->n ];
+}
diff -urN wf-/data.h wf/data.h
--- wf-/data.h	2015-12-20 00:00:00.000000000 +0900
+++ wf/data.h	2015-12-24 00:00:00.000000000 +0900
@@ -26,9 +26,11 @@
 #define type_point_symmetry		104
 #define type_mirror			105
 #define type_timeshift			106
+#define type_rdiv			107
 
 #define type_slide_way			120
 #define type_rot_way			130
+#define type_rdiv_way			131
 
 #define type_copy			200
 #define type_copy_rot			201
@@ -44,6 +46,9 @@
 	
 	/* work */
 	pos_t *t;
+	vec_t *v;
+	double sum_len;
+	int line_n;
 };
 
 struct op_data_set{
@@ -65,6 +70,16 @@
 	d3_t slide;
 };
 
+struct rdiv{
+	int n;
+	double rate;
+};
+
+struct rdiv_way{
+	int n;
+	struct way rate_way;
+};
+
 struct copy{
 	struct { int x, y, z; } n;
 	d3_t init, step;
@@ -88,10 +103,14 @@
 	affin_t af;
 	const eye_t *eye;
 	double sec;
+
+	const struct rdiv *rdiv;
+	int skip_af;
 } prm_t;
 
 void prm_set_eye_update(prm_t *prm, eye_t *eye);
 void data_draw(data_t *data, prm_t *prm);
 void op_data_draw(data_t *op, data_t *data, prm_t *prm);
+void wf_init_work_alloc(struct wire_frame *wf, d3_t *t_and_v);
 
 #endif
diff -urN wf-/wf_ex.c wf/wf_ex.c
--- wf-/wf_ex.c	2015-12-23 00:00:00.000000000 +0900
+++ wf/wf_ex.c	2015-12-24 00:00:00.000000000 +0900
@@ -160,10 +160,14 @@
 		sscanf(zoom_s, "%lf,%lf,%lf", &zoom.x, &zoom.y, &zoom.z);
 		grp_read(&grp, fopen(fn, "r"), &zoom);
 		grp_to_wf(&grp, &wf);
-		if((wf.t = malloc(sizeof(*wf.t) * wf.n)) == NULL) ERR("No Mem");
+		wf_init_work_alloc(&wf, NULL);
 
-		data.type = type_wire_frame;
-		data.p = &wf;
+		data.type = type_op_data_set;
+		data.p = &(struct op_data_set){
+		  .op = &(data_t){ type_rdiv_way, &(struct rdiv_way){
+		    .n=4, 
+		    .rate_way={.n=2,.vs=(double[]){0,0.2},.ts=(double[]){3,3},.ps=NULL,.dg=3} }},
+		  .data = &(data_t){ type_wire_frame, &wf } };
 	}
 
 	if(opt_idx("-demo", ac, av) > 0){
@@ -186,6 +190,12 @@
 		    .n = {5*2+1,4*2+1,2*2+1}, .init = {-20*5,-30*4,-40*2}, .step = {20,30,40} }},
 		  .data = &(data_t){ type_cross, (pos_t[]){{-4,0,0},{4,0,0}} } }};
 
+		data_t *rcube = &(data_t){ type_op_data_set, &(struct op_data_set){
+		  .op = &(data_t){ type_rdiv_way, &(struct rdiv_way){
+		    .n=4,
+		    .rate_way={ .n=2, .vs=(double[]){-0.5,1.0}, .ts=(double[]){3,3}, .ps=NULL, .dg=3 } } },
+		  .data = &(data_t){ type_cube } }};
+
 		data_t *cube = &(data_t){ type_op_data_set, &(struct op_data_set){
 		  .op = &(data_t){ type_slide_way, &(struct way){
 		    .n = 4, .vs = NULL,
@@ -198,7 +208,7 @@
 		    .n = 4, .vs = NULL,
                     .ps = (pos_t[]){{0,0,0},{0,10,0},{10,10,0},{10,0,0}},
                     .ts = (double[]){1,1,1,1}, .dg = 3 }},
-		  .data = &(data_t){ type_cube } }};
+		  .data = rcube }};
 
 		data_t *cube3 = &(data_t){ type_op_data_set, &(struct op_data_set){
 		  .op = &(data_t){ type_copy_timeshift, &(struct copy_timeshift){
@@ -310,8 +320,6 @@
 	while(key_work(&eye, &mode) != EOF){
 		xclear();
 
-		prm.sec = eye.sec;
-
 		if(mode % 2 == 1){
 			int x, y;
 			for(y=0; y<2; y++){