0:11

So the motivation, the question we want to address here is.

Â How to design the valid furniture like a shelf or a table.

Â So the problem we consider is robustness and stability.

Â Robustness means, means do not break.

Â This one example, is you have this kind of shelf and you put the heavy object here,

Â and this nail can be break, bent.

Â So this is a problem we have to avoid and also if you get this shape and

Â you put this heavy weight here, then this would probably topple.

Â So these are the problem we want to avoid.

Â However, in this simple case it's easy to see but if you have a very

Â complicated shape like this one, it's very hard to see how to design valid furniture.

Â 0:55

So that's a problem we want addressed and our approach is like previous

Â systems we introduced so far, we provide continuous structure simulation.

Â So given our user input, system applied physical analysis and

Â they identify which is valid or invalid so you can continuously be part of it.

Â The addition to it in this work we also provide active guidance to

Â maintain validity.

Â So in addition just telling you, you are invalid or you are valid.

Â System also guides the user to recover validity.

Â For example, if the user in this invalid region,

Â you are design is invalid and not only telling that you are bad.

Â It can also tell you how to fix it.

Â So the system is continuously provide active feedback how to go back to

Â the valid region.

Â So this is can be farther assist the user in the design process, so that's the idea.

Â And this is a special technique we will introduce,

Â is one annotation indicating valid range.

Â So here, in this angle, is not very good, not durable.

Â So, if you put weight here, then this nail will be broken.

Â However, if you rotate this, plank to vertical,

Â then it becomes stable, robust, it doesn't break.

Â But if you go beyond farther then again it's not robust, durable.

Â So system compute valid range of the angle you are manipulating and

Â the visualizing another annotation so

Â internally system runs many simulations and then finds the valid divisions.

Â So this is the stability analysis and annotation.

Â 2:38

So the another is stability.

Â So here the system identifies that this configuration is not stable.

Â If you physically fabricate this, this will topple.

Â So this is a [INAUDIBLE] but in addition to providing this feedback,

Â system also provides suggestions showing valid designs.

Â So when the user provide this, not only telling the user this is not stable,

Â the system generates body candidates this way and

Â the user just speaks long them and you get the product design.

Â 3:40

Yeah. Nothing special so far.

Â So here, as a user start rotating this plank.

Â If the angle is too much, then this joint will collapse.

Â The system profile is not durable feedback.

Â In addition, this not durable indicator, the system shows a valid lane.

Â So in this range it's okay.

Â 4:34

Our system also provides balance in a number of positions.

Â If this is geometric analysis but if it's not disconnected the system suggest

Â multiple choices to fix discontinuity And here in

Â this situation it will topple, so system suggest multiple candidates to fix it.

Â 6:23

[NOISE] Okay, so

Â let me again very briefly describe what's going on inside.

Â So what we presenting is how to prevent breaking and how to prevent toppling.

Â So first one is robustness analysis.

Â So if analyze bend force of joints.

Â And also in prevent toppling we put,

Â analyze force, contact force at the ground.

Â So let me explain one by one.

Â 6:57

So okay let's ask how to, let me just clarify how to prevent breaking.

Â So, suppose we have this kind of configuration, three planks and two nails.

Â And then we try to find the region where the nail is placed.

Â 7:12

And then in,

Â to do this we consider a space spanned by, nail joint bending forces.

Â So we compute bending force at this nail 1 on nail 2,

Â and then we put designs, in the space spanned by these forces,

Â applied bending force up right to these sets.

Â For example, in this configuration, it is located here.

Â You know there's no, if there's no bending force,

Â lambda 2 equal zero and lambda 1 is somewhere here.

Â So this is the best thing, so compute bending force and

Â then you put current design in this space and after that we have bodied range.

Â Right, if the bending force is too light, too large, it's not durable.

Â So bending force should be smaller than a specific threshold.

Â And it is end up with a kind of box region.

Â So if design is inside of this region it's durable, it's safe, it's okay.

Â But if it's outside it's not durable it's not okay.

Â So system needs to the suggest going back to this region.

Â 8:20

So yeah, so value to design is somewhere here.

Â So the task is moving from here to there.

Â So that's the starting point and then what we do is something like this.

Â So for our given current, no spin, non durable design

Â we gradually change a parameter and then we check the project tree.

Â You know, gradually change design and then you rotate in this fourth space.

Â And then, you see a trajectory.

Â So if you change one thing, you get this trajectory,

Â if you change another thing, you will get another trajectory.

Â So in the system, we test various trajectories, you know?

Â One point we try to change the angle here, in somewhere else,

Â you try to position something else.

Â We try many different variety or operations on the check trajectory.

Â And then, after checking trajectory,

Â we pick the one just going with the safe region and then show it, as a result.

Â So internally, systems learns a lot of physical simulation and we do not

Â explain data here, but internally we are giving you the same sensitivity analysis.

Â So it is a linear approximation.

Â So instead of computing individual one, we are approximating so

Â these linear single line then you can arithmetically compute collision,

Â safe collision faster and so that's what's going on.

Â 10:03

And the action force comes from floor to the furniture.

Â If the force is under the pointed side,

Â then it means that the for the floor and it means that there is a problem.

Â So in the force space diagram looks like this, so if.

Â So contact force should be always positive.

Â You know? Contact force needs,

Â needs to be positive, if negative, it means that the contact becomes fall

Â apart; which means the furniture topples over, stumbles.

Â So in, the task is to move the design back into this valid region.

Â So again, the same thing.

Â You compute the trajectory by checking many variations and

Â then to identify and find the good one.

Â 10:51

Ok, so little bit, maybe too fast but that's a brief summary.

Â So, we presented furniture design with durability, and stability analysis.

Â So system continously checks whether current design stable or durable.

Â And in addition to that,

Â system actively guide the user to go back to the valid region.

Â So to do so, internally, we apply joint force analysis in the force space.

Â So in the case of durability we compute bending force and the force of stability

Â we compute the contact force and then we try to move back into the safe region.

Â 11:38

And the physically valid design of objects is popular for

Â topic in this entry, and a couple of interesting works appear in this entry.

Â And one is Make it stand: Balancing shapes for 3D fabrication.

Â So this technique takes single 3D object and then tries to adjust the shapes so

Â that it actually stands, not topple.

Â So this is automatic optimization and the another is,

Â Stress relief: Improving structural strength of 3D printable objects.

Â So this one takes 3D object and print it.

Â However it also analyzes weakest bottle neck for example, this neck

Â can easily break, so system identifies it, and then make it more stronger.

Â So this kind of condition is heavily explored.

Â Our work is different because we try to guide the user through the modeling phase.

Â That's it, thank you.

Â