- pyapi mathutils.geometry.intersect_plane_plane

- isect_plane_plane_v3 uses better method
- minor refactor - arg name changes & some args as const.

4 files changed, 205 insertions, 138 deletions

diff --git a/source/blender/blenkernel/intern/camera.c b/source/blender/blenkernel/intern/camera.c
index da7c0ab1774..08e8a80750e 100644
--- a/source/blender/blenkernel/intern/camera.c
+++ b/source/blender/blenkernel/intern/camera.c
@@ -456,7 +456,7 @@ static void camera_to_frame_view_cb(const float co[3], void *user_data)
 	unsigned int i;
 
 	for (i= 0; i < 4; i++) {
-		float nd= -dist_to_plane_v3(co, data->frame_tx[i], data->normal_tx[i]);
+		float nd= dist_to_plane_v3(co, data->frame_tx[i], data->normal_tx[i]);
 		if (nd < data->dist_vals[i]) {
 			data->dist_vals[i]= nd;
 		}
@@ -530,55 +530,49 @@ int camera_view_frame_fit_to_scene(Scene *scene, struct View3D *v3d, Object *cam
 			mul_v3_v3fl(plane_tx[i], data_cb.normal_tx[i], data_cb.dist_vals[i]);
 		}
 
-		if ( (isect_plane_plane_v3(plane_isect_1, plane_isect_1_no,
-		                           plane_tx[0], data_cb.normal_tx[0],
-		                           plane_tx[2], data_cb.normal_tx[2]) == 0) ||
-		     (isect_plane_plane_v3(plane_isect_2, plane_isect_2_no,
-		                           plane_tx[1], data_cb.normal_tx[1],
-		                           plane_tx[3], data_cb.normal_tx[3]) == 0))
+		isect_plane_plane_v3(plane_isect_1, plane_isect_1_no,
+		                     plane_tx[0], data_cb.normal_tx[0],
+		                     plane_tx[2], data_cb.normal_tx[2]);
+		isect_plane_plane_v3(plane_isect_2, plane_isect_2_no,
+		                     plane_tx[1], data_cb.normal_tx[1],
+		                     plane_tx[3], data_cb.normal_tx[3]);
+
+		add_v3_v3v3(plane_isect_1_other, plane_isect_1, plane_isect_1_no);
+		add_v3_v3v3(plane_isect_2_other, plane_isect_2, plane_isect_2_no);
+
+		if (isect_line_line_v3(plane_isect_1, plane_isect_1_other,
+		                       plane_isect_2, plane_isect_2_other,
+		                       plane_isect_pt_1, plane_isect_pt_2) == 0)
 		{
-			/* this is very unlikely */
 			return FALSE;
 		}
 		else {
+			float cam_plane_no[3]= {0.0f, 0.0f, -1.0f};
+			float plane_isect_delta[3];
+			float plane_isect_delta_len;
 
-			add_v3_v3v3(plane_isect_1_other, plane_isect_1, plane_isect_1_no);
-			add_v3_v3v3(plane_isect_2_other, plane_isect_2, plane_isect_2_no);
-
-			if (isect_line_line_v3(plane_isect_1, plane_isect_1_other,
-			                       plane_isect_2, plane_isect_2_other,
-			                       plane_isect_pt_1, plane_isect_pt_2) == 0)
-			{
-				return FALSE;
-			}
-			else {
-				float cam_plane_no[3]= {0.0f, 0.0f, -1.0f};
-				float plane_isect_delta[3];
-				float plane_isect_delta_len;
-
-				mul_m3_v3(rot_obmat, cam_plane_no);
+			mul_m3_v3(rot_obmat, cam_plane_no);
 
-				sub_v3_v3v3(plane_isect_delta, plane_isect_pt_2, plane_isect_pt_1);
-				plane_isect_delta_len= len_v3(plane_isect_delta);
+			sub_v3_v3v3(plane_isect_delta, plane_isect_pt_2, plane_isect_pt_1);
+			plane_isect_delta_len= len_v3(plane_isect_delta);
 
-				if (dot_v3v3(plane_isect_delta, cam_plane_no) > 0.0f) {
-					copy_v3_v3(r_co, plane_isect_pt_1);
+			if (dot_v3v3(plane_isect_delta, cam_plane_no) > 0.0f) {
+				copy_v3_v3(r_co, plane_isect_pt_1);
 
-					/* offset shift */
-					normalize_v3(plane_isect_1_no);
-					madd_v3_v3fl(r_co, plane_isect_1_no, shift[1] * -plane_isect_delta_len);
-				}
-				else {
-					copy_v3_v3(r_co, plane_isect_pt_2);
+				/* offset shift */
+				normalize_v3(plane_isect_1_no);
+				madd_v3_v3fl(r_co, plane_isect_1_no, shift[1] * -plane_isect_delta_len);
+			}
+			else {
+				copy_v3_v3(r_co, plane_isect_pt_2);
 
-					/* offset shift */
-					normalize_v3(plane_isect_2_no);
-					madd_v3_v3fl(r_co, plane_isect_2_no, shift[0] * -plane_isect_delta_len);
-				}
+				/* offset shift */
+				normalize_v3(plane_isect_2_no);
+				madd_v3_v3fl(r_co, plane_isect_2_no, shift[0] * -plane_isect_delta_len);
+			}
 
 
-				return TRUE;
-			}
+			return TRUE;
 		}
 	}
 }
diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h
index 5c92d15c440..a2a4ffdc830 100644
--- a/source/blender/blenlib/BLI_math_geom.h
+++ b/source/blender/blenlib/BLI_math_geom.h
@@ -60,6 +60,7 @@ float dist_to_line_v2(const float p[2], const float l1[2], const float l2[2]);
 float dist_to_line_segment_v2(const float p[2], const float l1[2], const float l2[2]);
 void closest_to_line_segment_v2(float closest[2], const float p[2], const float l1[2], const float l2[2]);
 
+float dist_to_plane_normalized_v3(const float p[3], const float plane_co[3], const float plane_no_unit[3]);
 float dist_to_plane_v3(const float p[3], const float plane_co[3], const float plane_no[3]);
 float dist_to_line_segment_v3(const float p[3], const float l1[3], const float l2[3]);
 float closest_to_line_v3(float r[3], const float p[3], const float l1[3], const float l2[3]);
@@ -96,12 +97,13 @@ int isect_line_line_v3(const float v1[3], const float v2[3],
                        float i1[3], float i2[3]);
 int isect_line_line_strict_v3(const float v1[3], const float v2[3],
                               const float v3[3], const float v4[3],
-                              float vi[3], float *lambda);
+                              float vi[3], float *r_lambda);
 
 /*if clip is nonzero, will only return true if lambda is >= 0.0
   (i.e. intersection point is along positive d)*/
-int isect_ray_plane_v3(float p1[3], float d[3], float v0[3], 
-					   float v1[3], float v2[3], float *lambda, int clip);
+int isect_ray_plane_v3(const float p1[3], const float d[3],
+                       const float v0[3], const float v1[3], const float v2[3],
+                       float *r_lambda, const int clip);
 
 /**
  * Intersect line/plane, optionally treat line as directional (like a ray) with the no_flip argument.
@@ -126,19 +128,19 @@ int isect_line_plane_v3(float out[3], const float l1[3], const float l2[3],
  * @param plane_b_co The point on the second plane.
  * @param plane_b_no The normal of the second plane.
  */
-int isect_plane_plane_v3(float r_isect_co[3], float r_isect_no[3],
-                         const float plane_a_co[3], const float plane_a_no[3],
-                         const float plane_b_co[3], const float plane_b_no[3]);
+void isect_plane_plane_v3(float r_isect_co[3], float r_isect_no[3],
+                          const float plane_a_co[3], const float plane_a_no[3],
+                          const float plane_b_co[3], const float plane_b_no[3]);
 
 /* line/ray triangle */
 int isect_line_tri_v3(const float p1[3], const float p2[3],
-	const float v0[3], const float v1[3], const float v2[3], float *lambda, float uv[2]);
+	const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]);
 int isect_ray_tri_v3(const float p1[3], const float d[3],
-	const float v0[3], const float v1[3], const float v2[3], float *lambda, float uv[2]);
+	const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2]);
 int isect_ray_tri_threshold_v3(const float p1[3], const float d[3],
-	const float v0[3], const float v1[3], const float v2[3], float *lambda, float uv[2], const float threshold);
+	const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2], const float threshold);
 int isect_ray_tri_epsilon_v3(const float p1[3], const float d[3],
-	const float v0[3], const float v1[3], const float v2[3], float *lambda, float uv[2], const float epsilon);
+	const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float r_uv[2], const float epsilon);
 
 /* point in polygon */
 int isect_point_quad_v2(const float p[2], const float a[2], const float b[2], const float c[2], const float d[2]);
@@ -148,16 +150,16 @@ int isect_point_tri_v2_int(const int x1, const int y1, const int x2, const int y
 int isect_point_tri_prism_v3(const float p[3], const float v1[3], const float v2[3], const float v3[3]);
 
 void isect_point_quad_uv_v2(const float v0[2], const float v1[2], const float v2[2], const float v3[2],
-	const float pt[2], float *uv);
+                            const float pt[2], float r_uv[2]);
 void isect_point_face_uv_v2(const int isquad, const float v0[2], const float v1[2], const float v2[2],
-	const float v3[2], const float pt[2], float *uv);
+                            const float v3[2], const float pt[2], float r_uv[2]);
 
 /* other */
 int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const float radius,
-	const float v0[3], const float v1[3], const float v2[3], float *lambda, float ipoint[3]);
+	const float v0[3], const float v1[3], const float v2[3], float *r_lambda, float ipoint[3]);
 
 int isect_axial_line_tri_v3(const int axis, const float co1[3], const float co2[3],
-	const float v0[3], const float v1[3], const float v2[3], float *lambda);
+	const float v0[3], const float v1[3], const float v2[3], float *r_lambda);
 
 int isect_aabb_aabb_v3(const float min1[3], const float max1[3], const float min2[3], const float max2[3]);
 
@@ -184,7 +186,7 @@ void barycentric_transform(float pt_tar[3], float const pt_src[3],
 void barycentric_weights_v2(const float v1[2], const float v2[2], const float v3[2],
 	const float co[2], float w[3]);
 
-void resolve_tri_uv(float uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2]);
+void resolve_tri_uv(float r_uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2]);
 void resolve_quad_uv(float uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2]);
 
 /***************************** View & Projection *****************************/
diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c
index 1170e44b27b..9d42ee347d4 100644
--- a/source/blender/blenlib/intern/math_geom.c
+++ b/source/blender/blenlib/intern/math_geom.c
@@ -238,6 +238,15 @@ void closest_to_line_segment_v3(float closest[3], const float v1[3], const float
 }
 
 /* signed distance from the point to the plane in 3D */
+float dist_to_plane_normalized_v3(const float p[3], const float plane_co[3], const float plane_no_unit[3])
+{
+	float plane_co_other[3];
+
+	add_v3_v3v3(plane_co_other, plane_co, plane_no_unit);
+
+	return line_point_factor_v3(p, plane_co, plane_co_other);
+}
+
 float dist_to_plane_v3(const float p[3], const float plane_co[3], const float plane_no[3])
 {
 	float plane_no_unit[3];
@@ -246,7 +255,7 @@ float dist_to_plane_v3(const float p[3], const float plane_co[3], const float pl
 	normalize_v3_v3(plane_no_unit, plane_no);
 	add_v3_v3v3(plane_co_other, plane_co, plane_no_unit);
 
-	return -line_point_factor_v3(p, plane_co, plane_co_other);
+	return line_point_factor_v3(p, plane_co, plane_co_other);
 }
 
 /* distance v1 to line-piece v2-v3 in 3D */
@@ -601,7 +610,9 @@ int isect_point_quad_v2(const float pt[2], const float v1[2], const float v2[2],
    test if the line starting at p1 ending at p2 intersects the triangle v0..v2
    return non zero if it does 
 */
-int isect_line_tri_v3(const float p1[3], const float p2[3], const float v0[3], const float v1[3], const float v2[3], float *lambda, float uv[2])
+int isect_line_tri_v3(const float p1[3], const float p2[3],
+                      const float v0[3], const float v1[3], const float v2[3],
+                      float *r_lambda, float r_uv[2])
 {
 
 	float p[3], s[3], d[3], e1[3], e2[3], q[3];
@@ -626,12 +637,12 @@ int isect_line_tri_v3(const float p1[3], const float p2[3], const float v0[3], c
 	v = f * dot_v3v3(d, q);
 	if ((v < 0.0f)||((u + v) > 1.0f)) return 0;
 
-	*lambda = f * dot_v3v3(e2, q);
-	if ((*lambda < 0.0f)||(*lambda > 1.0f)) return 0;
+	*r_lambda = f * dot_v3v3(e2, q);
+	if ((*r_lambda < 0.0f)||(*r_lambda > 1.0f)) return 0;
 
-	if(uv) {
-		uv[0]= u;
-		uv[1]= v;
+	if(r_uv) {
+		r_uv[0]= u;
+		r_uv[1]= v;
 	}
 	
 	return 1;
@@ -640,7 +651,9 @@ int isect_line_tri_v3(const float p1[3], const float p2[3], const float v0[3], c
    test if the ray starting at p1 going in d direction intersects the triangle v0..v2
    return non zero if it does 
 */
-int isect_ray_tri_v3(const float p1[3], const float d[3], const float v0[3], const float v1[3], const float v2[3], float *lambda, float uv[2])
+int isect_ray_tri_v3(const float p1[3], const float d[3],
+                     const float v0[3], const float v1[3], const float v2[3],
+                     float *r_lambda, float r_uv[2])
 {
 	float p[3], s[3], e1[3], e2[3], q[3];
 	float a, f, u, v;
@@ -665,18 +678,20 @@ int isect_ray_tri_v3(const float p1[3], const float d[3], const float v0[3], con
 	v = f * dot_v3v3(d, q);
 	if ((v < 0.0f)||((u + v) > 1.0f)) return 0;
 
-	*lambda = f * dot_v3v3(e2, q);
-	if ((*lambda < 0.0f)) return 0;
+	*r_lambda = f * dot_v3v3(e2, q);
+	if ((*r_lambda < 0.0f)) return 0;
 
-	if(uv) {
-		uv[0]= u;
-		uv[1]= v;
+	if(r_uv) {
+		r_uv[0]= u;
+		r_uv[1]= v;
 	}
 	
 	return 1;
 }
 
-int isect_ray_plane_v3(float p1[3], float d[3], float v0[3], float v1[3], float v2[3], float *lambda, int clip)
+int isect_ray_plane_v3(const float p1[3], const float d[3],
+                       const float v0[3], const float v1[3], const float v2[3],
+                       float *r_lambda, const int clip)
 {
 	float p[3], s[3], e1[3], e2[3], q[3];
 	float a, f;
@@ -700,13 +715,15 @@ int isect_ray_plane_v3(float p1[3], float d[3], float v0[3], float v1[3], float
 	
 	/* v = f * dot_v3v3(d, q); */ /*UNUSED*/
 
-	*lambda = f * dot_v3v3(e2, q);
-	if (clip && (*lambda < 0.0f)) return 0;
+	*r_lambda = f * dot_v3v3(e2, q);
+	if (clip && (*r_lambda < 0.0f)) return 0;
 
 	return 1;
 }
 
-int isect_ray_tri_epsilon_v3(const float p1[3], const float d[3], const float v0[3], const float v1[3], const float v2[3], float *lambda, float uv[2], const float epsilon)
+int isect_ray_tri_epsilon_v3(const float p1[3], const float d[3],
+                             const float v0[3], const float v1[3], const float v2[3],
+                             float *r_lambda, float uv[2], const float epsilon)
 {
 	float p[3], s[3], e1[3], e2[3], q[3];
 	float a, f, u, v;
@@ -729,8 +746,8 @@ int isect_ray_tri_epsilon_v3(const float p1[3], const float d[3], const float v0
 	v = f * dot_v3v3(d, q);
 	if ((v < -epsilon)||((u + v) > 1.0f+epsilon)) return 0;
 
-	*lambda = f * dot_v3v3(e2, q);
-	if ((*lambda < 0.0f)) return 0;
+	*r_lambda = f * dot_v3v3(e2, q);
+	if ((*r_lambda < 0.0f)) return 0;
 
 	if(uv) {
 		uv[0]= u;
@@ -740,7 +757,9 @@ int isect_ray_tri_epsilon_v3(const float p1[3], const float d[3], const float v0
 	return 1;
 }
 
-int isect_ray_tri_threshold_v3(const float p1[3], const float d[3], const float v0[3], const float v1[3], const float v2[3], float *lambda, float *uv, const float threshold)
+int isect_ray_tri_threshold_v3(const float p1[3], const float d[3],
+                               const float v0[3], const float v1[3], const float v2[3],
+                               float *r_lambda, float r_uv[2], const float threshold)
 {
 	float p[3], s[3], e1[3], e2[3], q[3];
 	float a, f, u, v;
@@ -757,8 +776,8 @@ int isect_ray_tri_threshold_v3(const float p1[3], const float d[3], const float
 	sub_v3_v3v3(s, p1, v0);
 	
 	cross_v3_v3v3(q, s, e1);
-	*lambda = f * dot_v3v3(e2, q);
-	if ((*lambda < 0.0f)) return 0;
+	*r_lambda = f * dot_v3v3(e2, q);
+	if ((*r_lambda < 0.0f)) return 0;
 	
 	u = f * dot_v3v3(s, p);
 	v = f * dot_v3v3(d, q);
@@ -782,9 +801,9 @@ int isect_ray_tri_threshold_v3(const float p1[3], const float d[3], const float
 		return 0;
 	}
 
-	if(uv) {
-		uv[0]= u;
-		uv[1]= v;
+	if(r_uv) {
+		r_uv[0]= u;
+		r_uv[1]= v;
 	}
 	
 	return 1;
@@ -833,24 +852,16 @@ int isect_line_plane_v3(float out[3], const float l1[3], const float l2[3], cons
 	}
 }
 
-int isect_plane_plane_v3(float r_isect_co[3], float r_isect_no[3],
+/* note: return normal isnt unit length */
+void isect_plane_plane_v3(float r_isect_co[3], float r_isect_no[3],
                           const float plane_a_co[3], const float plane_a_no[3],
                           const float plane_b_co[3], const float plane_b_no[3])
 {
-	float p1_co_other[3], p2_co_other[3];
-	float isect_co_dummy[3];
-
-	cross_v3_v3v3(r_isect_no, plane_a_no, plane_b_no);
-	cross_v3_v3v3(p1_co_other, plane_a_no, r_isect_no);
-	cross_v3_v3v3(p2_co_other, plane_b_no, r_isect_no);
-
-	add_v3_v3(p1_co_other, plane_a_co);
-	add_v3_v3(p2_co_other, plane_b_co);
-
-	/* we could use either ix_1, ix_2 - doesnt matter in this case */
-	return isect_line_line_v3(plane_a_co, p1_co_other,
-	                          plane_b_co, p2_co_other,
-	                          r_isect_co, isect_co_dummy);
+	float plane_a_co_other[3];
+	cross_v3_v3v3(r_isect_no, plane_a_no, plane_b_no); /* direction is simply the cross product */
+	cross_v3_v3v3(plane_a_co_other, plane_a_no, r_isect_no);
+	add_v3_v3(plane_a_co_other, plane_a_co);
+	isect_line_plane_v3(r_isect_co, plane_a_co, plane_a_co_other, plane_b_co, plane_b_no, FALSE);
 }
 
 
@@ -893,7 +904,10 @@ static int getLowestRoot(const float a, const float b, const float c, const floa
 	return 0;
 }
 
-int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const float radius, const float v0[3], const float v1[3], const float v2[3], float *lambda, float ipoint[3])
+int isect_sweeping_sphere_tri_v3(
+        const float p1[3], const float p2[3], const float radius,
+        const float v0[3], const float v1[3], const float v2[3],
+        float *r_lambda, float ipoint[3])
 {
 	float e1[3], e2[3], e3[3], point[3], vel[3], /*dist[3],*/ nor[3], temp[3], bv[3];
 	float a, b, c, d, e, x, y, z, radius2=radius*radius;
@@ -960,14 +974,14 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 		if(z <= 0.0f && (x >= 0.0f && y >= 0.0f))
 		{
 		//(((unsigned int)z)& ~(((unsigned int)x)|((unsigned int)y))) & 0x80000000){
-			*lambda=t0;
+			*r_lambda=t0;
 			copy_v3_v3(ipoint,point);
 			return 1;
 		}
 	}
 
 
-	*lambda=1.0f;
+	*r_lambda=1.0f;
 
 /*---test points---*/
 	a=dot_v3v3(vel,vel);
@@ -977,7 +991,7 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 	b=2.0f*dot_v3v3(vel,temp);
 	c=dot_v3v3(temp,temp)-radius2;
 
-	if(getLowestRoot(a, b, c, *lambda, lambda))
+	if(getLowestRoot(a, b, c, *r_lambda, r_lambda))
 	{
 		copy_v3_v3(ipoint,v0);
 		found_by_sweep=1;
@@ -988,7 +1002,7 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 	b=2.0f*dot_v3v3(vel,temp);
 	c=dot_v3v3(temp,temp)-radius2;
 
-	if(getLowestRoot(a, b, c, *lambda, lambda))
+	if(getLowestRoot(a, b, c, *r_lambda, r_lambda))
 	{
 		copy_v3_v3(ipoint,v1);
 		found_by_sweep=1;
@@ -999,7 +1013,7 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 	b=2.0f*dot_v3v3(vel,temp);
 	c=dot_v3v3(temp,temp)-radius2;
 
-	if(getLowestRoot(a, b, c, *lambda, lambda))
+	if(getLowestRoot(a, b, c, *r_lambda, r_lambda))
 	{
 		copy_v3_v3(ipoint,v2);
 		found_by_sweep=1;
@@ -1020,13 +1034,13 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 	b=2.0f*(elen2*dot_v3v3(vel,bv)-edotv*edotbv);
 	c=elen2*(radius2-dot_v3v3(bv,bv))+edotbv*edotbv;
 
-	if(getLowestRoot(a, b, c, *lambda, &newLambda))
+	if(getLowestRoot(a, b, c, *r_lambda, &newLambda))
 	{
 		e=(edotv*newLambda-edotbv)/elen2;
 
 		if(e >= 0.0f && e <= 1.0f)
 		{
-			*lambda = newLambda;
+			*r_lambda = newLambda;
 			copy_v3_v3(ipoint,e1);
 			mul_v3_fl(ipoint,e);
 			add_v3_v3(ipoint, v0);
@@ -1044,13 +1058,13 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 	b=2.0f*(elen2*dot_v3v3(vel,bv)-edotv*edotbv);
 	c=elen2*(radius2-dot_v3v3(bv,bv))+edotbv*edotbv;
 
-	if(getLowestRoot(a, b, c, *lambda, &newLambda))
+	if(getLowestRoot(a, b, c, *r_lambda, &newLambda))
 	{
 		e=(edotv*newLambda-edotbv)/elen2;
 
 		if(e >= 0.0f && e <= 1.0f)
 		{
-			*lambda = newLambda;
+			*r_lambda = newLambda;
 			copy_v3_v3(ipoint,e2);
 			mul_v3_fl(ipoint,e);
 			add_v3_v3(ipoint, v0);
@@ -1073,13 +1087,13 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 	b=2.0f*(elen2*dot_v3v3(vel,bv)-edotv*edotbv);
 	c=elen2*(radius2-dot_v3v3(bv,bv))+edotbv*edotbv;
 
-	if(getLowestRoot(a, b, c, *lambda, &newLambda))
+	if(getLowestRoot(a, b, c, *r_lambda, &newLambda))
 	{
 		e=(edotv*newLambda-edotbv)/elen2;
 
 		if(e >= 0.0f && e <= 1.0f)
 		{
-			*lambda = newLambda;
+			*r_lambda = newLambda;
 			copy_v3_v3(ipoint,e3);
 			mul_v3_fl(ipoint,e);
 			add_v3_v3(ipoint, v1);
@@ -1090,7 +1104,8 @@ int isect_sweeping_sphere_tri_v3(const float p1[3], const float p2[3], const flo
 
 	return found_by_sweep;
 }
-int isect_axial_line_tri_v3(const int axis, const float p1[3], const float p2[3], const float v0[3], const float v1[3], const float v2[3], float *lambda)
+int isect_axial_line_tri_v3(const int axis, const float p1[3], const float p2[3],
+                            const float v0[3], const float v1[3], const float v2[3], float *r_lambda)
 {
 	float p[3], e1[3], e2[3];
 	float u, v, f;
@@ -1127,9 +1142,9 @@ int isect_axial_line_tri_v3(const int axis, const float p1[3], const float p2[3]
 
 	if ((u < 0.0f) || ((u + v) > 1.0f)) return 0;
 
-	*lambda = (p[a0]+u*e1[a0]+v*e2[a0])/(p2[a0]-p1[a0]);
+	*r_lambda = (p[a0]+u*e1[a0]+v*e2[a0])/(p2[a0]-p1[a0]);
 
-	if ((*lambda < 0.0f) || (*lambda > 1.0f)) return 0;
+	if ((*r_lambda < 0.0f) || (*r_lambda > 1.0f)) return 0;
 
 	return 1;
 }
@@ -1203,7 +1218,7 @@ int isect_line_line_v3(const float v1[3], const float v2[3], const float v3[3],
 /* Intersection point strictly between the two lines
  * 0 when no intersection is found 
  * */
-int isect_line_line_strict_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3], float vi[3], float *lambda)
+int isect_line_line_strict_v3(const float v1[3], const float v2[3], const float v3[3], const float v4[3], float vi[3], float *r_lambda)
 {
 	float a[3], b[3], c[3], ab[3], cb[3], ca[3], dir1[3], dir2[3];
 	float d;
@@ -1237,12 +1252,9 @@ int isect_line_line_strict_v3(const float v1[3], const float v2[3], const float
 		{
 			mul_v3_fl(a, f1);
 			add_v3_v3v3(vi, v1, a);
-			
-			if (lambda != NULL)
-			{
-				*lambda = f1;
-			}
-			
+
+			if (r_lambda) *r_lambda = f1;
+
 			return 1; /* intersection found */
 		}
 		else
@@ -1306,7 +1318,7 @@ float line_point_factor_v2(const float p[2], const float l1[2], const float l2[2
 }
 
 /* Similar to LineIntersectsTriangleUV, except it operates on a quad and in 2d, assumes point is in quad */
-void isect_point_quad_uv_v2(const float v0[2], const float v1[2], const float v2[2], const float v3[2], const float pt[2], float *uv)
+void isect_point_quad_uv_v2(const float v0[2], const float v1[2], const float v2[2], const float v3[2], const float pt[2], float r_uv[2])
 {
 	float x0,y0, x1,y1, wtot, v2d[2], w1, w2;
 	
@@ -1331,7 +1343,7 @@ void isect_point_quad_uv_v2(const float v0[2], const float v1[2], const float v2
 		wtot = w1+w2;
 		/*w1 = w1/wtot;*/
 		/*w2 = w2/wtot;*/
-		uv[0] = w1/wtot;
+		r_uv[0] = w1/wtot;
 	} else {
 		/* lines are parallel, lambda_cp_line_ex is 3d grrr */
 		/*printf("\tparallel1\n");*/
@@ -1353,7 +1365,7 @@ void isect_point_quad_uv_v2(const float v0[2], const float v1[2], const float v2
 		v2d[1] = pt[1]-pt_on_line[1];
 		w2 = len_v2(v2d);
 		wtot = w1+w2;
-		uv[0] = w1/wtot;	
+		r_uv[0] = w1/wtot;
 	}
 	
 	/* Same as above to calc the uv[1] value, alternate calculation */
@@ -1371,7 +1383,7 @@ void isect_point_quad_uv_v2(const float v0[2], const float v1[2], const float v2
 		v2d[1] = y1-v1[1];
 		w2 = len_v2(v2d);
 		wtot = w1+w2;
-		uv[1] = w1/wtot;
+		r_uv[1] = w1/wtot;
 	} else {
 		/* lines are parallel, lambda_cp_line_ex is 3d grrr */
 		/*printf("\tparallel2\n");*/
@@ -1394,23 +1406,23 @@ void isect_point_quad_uv_v2(const float v0[2], const float v1[2], const float v2
 		v2d[1] = pt[1]-pt_on_line[1];
 		w2 = len_v2(v2d);
 		wtot = w1+w2;
-		uv[1] = w1/wtot;
+		r_uv[1] = w1/wtot;
 	}
 	/* may need to flip UV's here */
 }
 
 /* same as above but does tri's and quads, tri's are a bit of a hack */
-void isect_point_face_uv_v2(const int isquad, const float v0[2], const float v1[2], const float v2[2], const float v3[2], const float pt[2], float *uv)
+void isect_point_face_uv_v2(const int isquad, const float v0[2], const float v1[2], const float v2[2], const float v3[2], const float pt[2], float r_uv[2])
 {
 	if (isquad) {
-		isect_point_quad_uv_v2(v0, v1, v2, v3, pt, uv);
+		isect_point_quad_uv_v2(v0, v1, v2, v3, pt, r_uv);
 	}
 	else {
 		/* not for quads, use for our abuse of LineIntersectsTriangleUV */
 		float p1_3d[3], p2_3d[3], v0_3d[3], v1_3d[3], v2_3d[3], lambda;
 			
-		p1_3d[0] = p2_3d[0] = uv[0];
-		p1_3d[1] = p2_3d[1] = uv[1];
+		p1_3d[0] = p2_3d[0] = r_uv[0];
+		p1_3d[1] = p2_3d[1] = r_uv[1];
 		p1_3d[2] = 1.0f;
 		p2_3d[2] = -1.0f;
 		v0_3d[2] = v1_3d[2] = v2_3d[2] = 0.0;
@@ -1427,7 +1439,7 @@ void isect_point_face_uv_v2(const int isquad, const float v0[2], const float v1[
 		copy_v2_v2(v2_3d, v2);
 		
 		/* Doing this in 3D is not nice */
-		isect_line_tri_v3(p1_3d, p2_3d, v0_3d, v1_3d, v2_3d, &lambda, uv);
+		isect_line_tri_v3(p1_3d, p2_3d, v0_3d, v1_3d, v2_3d, &lambda, r_uv);
 	}
 }
 
@@ -1993,7 +2005,7 @@ void interp_cubic_v3(float x[3], float v[3], const float x1[3], const float v1[3
 #define IS_ZERO(x) ((x>(-DBL_EPSILON) && x<DBL_EPSILON) ? 1 : 0)
 
 /* Barycentric reverse  */
-void resolve_tri_uv(float uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2])
+void resolve_tri_uv(float r_uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2])
 {
 	/* find UV such that
 	   t= u*t0 + v*t1 + (1-u-v)*t2
@@ -2005,13 +2017,13 @@ void resolve_tri_uv(float uv[2], const float st[2], const float st0[2], const fl
 	if(IS_ZERO(det)==0)	{  /* det should never be zero since the determinant is the signed ST area of the triangle. */
 		const double x[]= {st[0]-st2[0], st[1]-st2[1]};
 
-		uv[0]= (float)((d*x[0] - b*x[1])/det);
-		uv[1]= (float)(((-c)*x[0] + a*x[1])/det);
-	} else zero_v2(uv);
+		r_uv[0]= (float)((d*x[0] - b*x[1])/det);
+		r_uv[1]= (float)(((-c)*x[0] + a*x[1])/det);
+	} else zero_v2(r_uv);
 }
 
 /* bilinear reverse */
-void resolve_quad_uv(float uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2])
+void resolve_quad_uv(float r_uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2])
 {
 	const double signed_area= (st0[0]*st1[1] - st0[1]*st1[0]) + (st1[0]*st2[1] - st1[1]*st2[0]) +
 	                          (st2[0]*st3[1] - st2[1]*st3[0]) + (st3[0]*st0[1] - st3[1]*st0[0]);
@@ -2029,25 +2041,25 @@ void resolve_quad_uv(float uv[2], const float st[2], const float st0[2], const f
 	const double denom= a - 2*b + fC;
 
 	// clear outputs
-	zero_v2(uv);
+	zero_v2(r_uv);
 
 	if(IS_ZERO(denom)!=0) {
 		const double fDen= a-fC;
 		if(IS_ZERO(fDen)==0)
-			uv[0]= (float)(a / fDen);
+			r_uv[0]= (float)(a / fDen);
 	} else {
 		const double desc_sq= b*b - a*fC;
 		const double desc= sqrt(desc_sq<0.0?0.0:desc_sq);
 		const double s= signed_area>0 ? (-1.0) : 1.0;
 
-		uv[0]= (float)(( (a-b) + s * desc ) / denom);
+		r_uv[0]= (float)(( (a-b) + s * desc ) / denom);
 	}
 
 	/* find UV such that
 	  fST = (1-u)(1-v)*ST0 + u*(1-v)*ST1 + u*v*ST2 + (1-u)*v*ST3 */
 	{
-		const double denom_s= (1-uv[0])*(st0[0]-st3[0]) + uv[0]*(st1[0]-st2[0]);
-		const double denom_t= (1-uv[0])*(st0[1]-st3[1]) + uv[0]*(st1[1]-st2[1]);
+		const double denom_s= (1-r_uv[0])*(st0[0]-st3[0]) + r_uv[0]*(st1[0]-st2[0]);
+		const double denom_t= (1-r_uv[0])*(st0[1]-st3[1]) + r_uv[0]*(st1[1]-st2[1]);
 		int i= 0; double denom= denom_s;
 
 		if(fabs(denom_s)<fabs(denom_t)) {
@@ -2056,7 +2068,7 @@ void resolve_quad_uv(float uv[2], const float st[2], const float st0[2], const f
 		}
 
 		if(IS_ZERO(denom)==0)
-			uv[1]= (float) (( (1.0f-uv[0])*(st0[i]-st[i]) + uv[0]*(st1[i]-st[i]) ) / denom);
+			r_uv[1]= (float) (( (1.0f-r_uv[0])*(st0[i]-st[i]) + r_uv[0]*(st1[i]-st[i]) ) / denom);
 	}
 }
 
diff --git a/source/blender/python/mathutils/mathutils_geometry.c b/source/blender/python/mathutils/mathutils_geometry.c
index 3bf2997e8c9..2f79dfd9914 100644
--- a/source/blender/python/mathutils/mathutils_geometry.c
+++ b/source/blender/python/mathutils/mathutils_geometry.c
@@ -497,6 +497,65 @@ static PyObject *M_Geometry_intersect_line_plane(PyObject *UNUSED(self), PyObjec
 	}
 }
 
+PyDoc_STRVAR(M_Geometry_intersect_plane_plane_doc,
+".. function:: intersect_plane_plane(plane_a_co, plane_a_no, plane_b_co, plane_b_no)\n"
+"\n"
+"   Return the intersection between two planes\n"
+"\n"
+"   :arg plane_a_co: Point on the first plane\n"
+"   :type plane_a_co: :class:`mathutils.Vector`\n"
+"   :arg plane_a_no: Normal of the first plane\n"
+"   :type plane_a_no: :class:`mathutils.Vector`\n"
+"   :arg plane_b_co: Point on the second plane\n"
+"   :type plane_b_co: :class:`mathutils.Vector`\n"
+"   :arg plane_b_no: Normal of the second plane\n"
+"   :type plane_b_no: :class:`mathutils.Vector`\n"
+"   :return: The line of the intersection represented as a point and a vector\n"
+"   :rtype: tuple pair of :class:`mathutils.Vector`\n"
+);
+static PyObject *M_Geometry_intersect_plane_plane(PyObject *UNUSED(self), PyObject* args)
+{
+	PyObject *ret;
+	VectorObject *plane_a_co, *plane_a_no, *plane_b_co, *plane_b_no;
+
+	float isect_co[3];
+	float isect_no[3];
+
+	if (!PyArg_ParseTuple(args, "O!O!O!O!|i:intersect_plane_plane",
+	                      &vector_Type, &plane_a_co,
+	                      &vector_Type, &plane_a_no,
+	                      &vector_Type, &plane_b_co,
+	                      &vector_Type, &plane_b_no))
+	{
+		return NULL;
+	}
+
+	if (    BaseMath_ReadCallback(plane_a_co) == -1 ||
+	        BaseMath_ReadCallback(plane_a_no) == -1 ||
+	        BaseMath_ReadCallback(plane_b_co) == -1 ||
+	        BaseMath_ReadCallback(plane_b_no) == -1)
+	{
+		return NULL;
+	}
+
+	if (ELEM4(2, plane_a_co->size, plane_a_no->size, plane_b_co->size, plane_b_no->size)) {
+		PyErr_SetString(PyExc_ValueError,
+		                "geometry.intersect_plane_plane(...): "
+		                " can't use 2D Vectors");
+		return NULL;
+	}
+
+	isect_plane_plane_v3(isect_co, isect_no,
+	                     plane_a_co->vec, plane_a_no->vec,
+	                     plane_b_co->vec, plane_b_no->vec);
+
+	normalize_v3(isect_no);
+
+	ret= PyTuple_New(2);
+	PyTuple_SET_ITEM(ret, 0, newVectorObject(isect_co, 3, Py_NEW, NULL));
+	PyTuple_SET_ITEM(ret, 1, newVectorObject(isect_no, 3, Py_NEW, NULL));
+	return ret;
+}
 
 PyDoc_STRVAR(M_Geometry_intersect_line_sphere_doc,
 ".. function:: intersect_line_sphere(line_a, line_b, sphere_co, sphere_radius, clip=True)\n"
@@ -1211,7 +1270,7 @@ static PyMethodDef M_Geometry_methods[]= {
 	{"intersect_line_line", (PyCFunction) M_Geometry_intersect_line_line, METH_VARARGS, M_Geometry_intersect_line_line_doc},
 	{"intersect_line_line_2d", (PyCFunction) M_Geometry_intersect_line_line_2d, METH_VARARGS, M_Geometry_intersect_line_line_2d_doc},
 	{"intersect_line_plane", (PyCFunction) M_Geometry_intersect_line_plane, METH_VARARGS, M_Geometry_intersect_line_plane_doc},
-	/* TODO: isect_plane_plane_v3 --> intersect_plane_plane */
+	{"intersect_plane_plane", (PyCFunction) M_Geometry_intersect_plane_plane, METH_VARARGS, M_Geometry_intersect_plane_plane_doc},
 	{"intersect_line_sphere", (PyCFunction) M_Geometry_intersect_line_sphere, METH_VARARGS, M_Geometry_intersect_line_sphere_doc},
 	{"intersect_line_sphere_2d", (PyCFunction) M_Geometry_intersect_line_sphere_2d, METH_VARARGS, M_Geometry_intersect_line_sphere_2d_doc},
 	{"distance_point_to_plane", (PyCFunction) M_Geometry_distance_point_to_plane, METH_VARARGS, M_Geometry_distance_point_to_plane_doc},