3D angle constraint for BIM door
Hello, I'm having troubles using the 3D angle constraint. My 2 selected planes are not rotated using the selected axis (a line defined through the hinges), they always seem to be rotating along the axis through the origin point.
Am I misinterpreting something here? I would expect the selected entity using the axis option becomes the rotating axis and not the origin point of the model.
Comments
-
You are right: this does not work. I would send in an SR.
In my test I have to use a rigid set constraint between two edges to control the axis. The axis of the angular constraint is ignored.0 -
Hello Dirk, Roy,
Instead of RigidSet creation, you need coincidence constraint for door and frame edges. Please see the attached model (DoorTest_Roy.dwg).
And even in this situation the model is not fully constrained. To have expected behavior it is better to have a fixed object. Strictly speaking, you can not be sure what will rotate: frame or door. So In my second example, I added Fixation to the frame face and its edge=axis. After that PlanarAngle constraint can be created and fixed edge can be chosen as an axis (DoorTest_ilyat.dwg).0 -
@Ilya Tatarnikov:
Keep in mind that my model was merely created to demonstrate the axis behavior of the angular constraint.
I will study your answer in more detail later today. For now your answer really only confirms my conclusion: The planar angle constraint ignores the axis, additional constraints are required.0 -
@Ilya Tatarnikov:
Your model confirms my previous findings. The planar angle constraint ignores its axis. Without the Coincident_3 constraint the angle constraint would use the Y axis instead.
But I have noticed an interesting and useful side-effect (?). If the angular constraint is replaced by a a version without an axis, changing the DoorAngle to 170 has the same result as changing this parameter to 10. This is not the case if the angular constrain does have an axis. So the axis seems to give directionality to the angle. But this is a bit cryptic of course. And not in keeping with the behavior of other dimensional constraints. Although I would prefer all dimensional constraints to have directionality.0 -
Believe me, it works. I just recreated PlanarAngle constraint in your model and do not see any issues after that. So, a mistake is somewhere in constraint creation on your side.
As for "side-effect" - the axis makes it possible to control the direction of the angle inside geometrical solver. This type of constraint was intentionally introduced to allow this possibility to the user.0 -
@Ilya Tatarnikov:
My last post is based on a test with your model.
My understanding of the axis of a planar angle constraint is that it is the line where the two planes (if extended) intersect. If I remove the Coincident_3 constraint in your model and change the DoorAngle to 45, the door rotates around the Y-axis (not the axis of the constraint). And the intersection line of the two planar faces no longer coincides with the constraint axis. Are you saying that you are seeing a different result?0 -
No, the result is the same you described. Strange indeed. Will try to investigate.
0 -
Roy,
I discussed planar angle behavior with our constraint solver team and they explained me - this is by design. Without coincident constraint the axis playing the role of indicator for the angle constraint direction counting. In the general case, the axis may lie not on the intersection of planes (again, in the general case planar angle can be specified for toroidal faces which has no planar faces. See attached 3ToPAng.dwg).
So, to obtain natural behavior of the Door model, the user must create additional coincident constraint.0 -
@Ilya Tatarnikov:
Thank you for confirming our findings. IMO this is too cryptic. If the axis only serves to control the direction of the angle why do you have to specify the actual intersection line when applying this constraint?0 -
Roy,
If you want to dig inside solver mathematics, I can try to find technical data sheet about planar angle realization, but I almost sure it would be boring.by the way: how do you answer my messages? I can not find a magic button.
0 -
@Ilya Tatarnikov:
I don't think I need that data sheet. I still know my way around vectors, planes, normals and angles. But improved documentation is of course welcome. This would help all users who are struggling with these features. As this topic demonstrates: even three experienced CAD operators can get confused.Regarding your 'magic button' question:
If you type '@' followed by the first letters of a user name a popup list will appear.0 -
Funny, not long after my post i indeed discovered i had to add an coincidence constraint. But i used the hinge planes. Didn't look into this thread untill now.
Conclusion is indeed like Roy says, it is confusing.
Thank you both for your valuable contributions.0 -
@Roy Klein Gebbinck
I learned. Thank you!
I'll try to find a way to extend the Help0
