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Query "bodies this side of plane "?
MichaelPascoe
Member Posts: 322 PRO
Best Answers

kevin_o_toole_1 Onshape Employees, Developers, HDM Posts: 522Not with just a query.
A simple solution is to just evaluate all part bounding boxes and check the bounds directly. To make it faster, you could evaluate 1 bound instead of 6 with a clever evDistance: Evaluate evDistance between each body and faroff plane pointing toward the desired split plane, e.g. plane(vector(500, 0, 0) * meter, X_DIRECTION). A resulting distance over 500 meters means the body is fully on the positivex side of the plane YZ plane.
Neither way will win any award for efficiency but they shouldn't be prohibitively timeconsuming unless there are thousands of parts.2 
Jacob_Corder Member Posts: 37 PROyou could use evdistance on all the bodies. then get the direction between the evdistance side points.
var offsetPlane = plane(plane.origin + (plane.normal * 0.1*millimeter),plane.normal,plane.x);
for(var i=0;i<size(bodies);i+=1)
{
var dist = evDistance(context,{
"side0":plane,
"side1":body[i]});
if(tolerantEquals(dist.distance, 0*meter)
{
//Re run it with the offset plane to detect if it is just touching the body or if it is intersecting it.
dist = evDistance(context,{
"side0":offsetPlane ,
"side1":body[i]});
//If this returns > 0 meter then you know that its touching the original plane but not this one. this tells you its behind your plane but touching your plane. Adjust the offset plane distance to fine tune to your application.
}
if(tolerantEquals(dist.distance,0*meter)==false)
{
var directionTo = normalize( dist.sides[1].point dist.sides[0].point );
if(angleBetween(directionTo,plane.normal) > angleBetween(directionTo,plane.normal*1)
{
// this should be on the back side of the plane.
}
}
}
my logic may be flipped in here but the point is to get the mid distance direction from the plane to each point on the bodies to determine if they are in front or in back of the plane.
I think.
1
Answers
A simple solution is to just evaluate all part bounding boxes and check the bounds directly. To make it faster, you could evaluate 1 bound instead of 6 with a clever evDistance: Evaluate evDistance between each body and faroff plane pointing toward the desired split plane, e.g. plane(vector(500, 0, 0) * meter, X_DIRECTION). A resulting distance over 500 meters means the body is fully on the positivex side of the plane YZ plane.
Neither way will win any award for efficiency but they shouldn't be prohibitively timeconsuming unless there are thousands of parts.
var offsetPlane = plane(plane.origin + (plane.normal * 0.1*millimeter),plane.normal,plane.x);
for(var i=0;i<size(bodies);i+=1)
{
var dist = evDistance(context,{
"side0":plane,
"side1":body[i]});
if(tolerantEquals(dist.distance, 0*meter)
{
//Re run it with the offset plane to detect if it is just touching the body or if it is intersecting it.
dist = evDistance(context,{
"side0":offsetPlane ,
"side1":body[i]});
//If this returns > 0 meter then you know that its touching the original plane but not this one. this tells you its behind your plane but touching your plane. Adjust the offset plane distance to fine tune to your application.
}
if(tolerantEquals(dist.distance,0*meter)==false)
{
var directionTo = normalize( dist.sides[1].point dist.sides[0].point );
if(angleBetween(directionTo,plane.normal) > angleBetween(directionTo,plane.normal*1)
{
// this should be on the back side of the plane.
}
}
}
my logic may be flipped in here but the point is to get the mid distance direction from the plane to each point on the bodies to determine if they are in front or in back of the plane.
I think.