How does one position an object whose shape is changed in space? For example, a ball is stretched and flattened; how do we know at which points in space it is stretched, and at which points it's flattened?
aravmisra
That's a great question and I suspect (but don't know) that it has to do with the direction of motion, and the material properties? For example, with the bouncing ball, the ball is moving such that it is bouncing up and down and to the right, as well as has material properties such that it compresses as it interacts with the ground. THere's perhaps more information needed, but it seems like those two components are basic building blocks! Anyone else feel free to weigh in.
RishSharma7
I also agree that it must be extremely difficult to understand how to accurately depict an object being changed in space, especially after it makes contact with something else. So, I did a bit of digging and found a research paper that goes really in-depth about Squash and Stretch Stylization, how it works, the formulas involved with it, and algorithms for utilizing it. You may need your Calnet ID to access it via IEEE. I'll link the PDF directly, and the site you can use to access it if that doesn't work.
I also found a video for blender that does a super simple rig for squash and stretch: https://www.youtube.com/watch?v=6nDlF4lkGFg (pay close attention to what dimension(s) are being manipulated as he squashes/stretches the object)
This other video, https://www.youtube.com/watch?v=r17Csq0V6ok, also goes over the basics of squash and stretch as well as animating it in 3D if you prefer to watch something. Much like 2d animation, 3d animation is taken frame by frame by manipulating your object relevant to its environment (like when the ball hits the ground it has a visible impact, same with the lamp it has to "brace")
jamespear
When I took an animation class in high school, I remember this video being particularly helpful in understanding the fundamentals of animation https://m.youtube.com/watch?v=uDqjIdI4bF4&pp=ygUXUHJpbmNpcGx3cyBvZiBhbmltYXRpb24%3D. I am excited to see how we see animation from a computer graphics perspective!
maxwelljin
I also agree that it’s dependent on the material properties. I think we can define the original shape and apply transformations, like scaling, translation, and rotation. The combination of these transformations will result in the final deformed shape of the object. We can apply different scale factors to different parts of the object.
I’ve also found a YouTube video: https://www.youtube.com/watch?v=F_LtpgpTHA8
The video discusses how to create a squash and stretch effect in Unity with code.
SKwon1220
Adding on to the ongoing discussion, could we possibly define which points in space are stretched or flattened using some sort of mapping between different spaces like we did for world and screen spaces for textures?
antony-zhao
One example of this I've seen fairly often is in Overwatch, where a lot of the animations are stretched (especially in like highlight intros). Still, it's almost impossible to notice unless you slow it down/go frame by frame. https://youtu.be/Lk4coGVVfVU
Admittedly, they are quite funny when played frame by frame, but it's interesting just how imperceptible they are when played in real-time.
OnceLim
Stretching and squashing is very prevalent in fight/action-heavy animations. I believe this is very important to show the range of motion, but sometimes its overused and too heavily distorted that it almost looks sloppy and funny. An example can be seen in a fight scene in Naruto when Naruto verses Pain in https://www.youtube.com/watch?v=mxjL6X4vZHk&ab_channel=Nintaigen.
Squash and Stretch is essential in animation but we shouldn't overuse it as seen in the example.
anavmehta12
The reason we apply squash and stretch is to show the mass of an object, the more an object squashes indicates a softer, lighter object like a balloon while an object that doesn't stretch at all could be a bowling ball or a rock.
AlsonC
I also have the question about the position of an object. Is this determined based on the center of the object, and is that by extension based on a physics equation?
grafour
pixar lamp! sorry i love this animation so much as a kid.https://www.youtube.com/watch?v=PGKmexNTHNE
How does one position an object whose shape is changed in space? For example, a ball is stretched and flattened; how do we know at which points in space it is stretched, and at which points it's flattened?
That's a great question and I suspect (but don't know) that it has to do with the direction of motion, and the material properties? For example, with the bouncing ball, the ball is moving such that it is bouncing up and down and to the right, as well as has material properties such that it compresses as it interacts with the ground. THere's perhaps more information needed, but it seems like those two components are basic building blocks! Anyone else feel free to weigh in.
I also agree that it must be extremely difficult to understand how to accurately depict an object being changed in space, especially after it makes contact with something else. So, I did a bit of digging and found a research paper that goes really in-depth about Squash and Stretch Stylization, how it works, the formulas involved with it, and algorithms for utilizing it. You may need your Calnet ID to access it via IEEE. I'll link the PDF directly, and the site you can use to access it if that doesn't work.
PDF: https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=5728801
Site: https://ieeexplore.ieee.org/document/5728801
I also found a video for blender that does a super simple rig for squash and stretch: https://www.youtube.com/watch?v=6nDlF4lkGFg (pay close attention to what dimension(s) are being manipulated as he squashes/stretches the object)
This other video, https://www.youtube.com/watch?v=r17Csq0V6ok, also goes over the basics of squash and stretch as well as animating it in 3D if you prefer to watch something. Much like 2d animation, 3d animation is taken frame by frame by manipulating your object relevant to its environment (like when the ball hits the ground it has a visible impact, same with the lamp it has to "brace")
When I took an animation class in high school, I remember this video being particularly helpful in understanding the fundamentals of animation https://m.youtube.com/watch?v=uDqjIdI4bF4&pp=ygUXUHJpbmNpcGx3cyBvZiBhbmltYXRpb24%3D. I am excited to see how we see animation from a computer graphics perspective!
I also agree that it’s dependent on the material properties. I think we can define the original shape and apply transformations, like scaling, translation, and rotation. The combination of these transformations will result in the final deformed shape of the object. We can apply different scale factors to different parts of the object.
I’ve also found a YouTube video: https://www.youtube.com/watch?v=F_LtpgpTHA8
The video discusses how to create a squash and stretch effect in Unity with code.
Adding on to the ongoing discussion, could we possibly define which points in space are stretched or flattened using some sort of mapping between different spaces like we did for world and screen spaces for textures?
One example of this I've seen fairly often is in Overwatch, where a lot of the animations are stretched (especially in like highlight intros). Still, it's almost impossible to notice unless you slow it down/go frame by frame. https://youtu.be/Lk4coGVVfVU
Admittedly, they are quite funny when played frame by frame, but it's interesting just how imperceptible they are when played in real-time.
Stretching and squashing is very prevalent in fight/action-heavy animations. I believe this is very important to show the range of motion, but sometimes its overused and too heavily distorted that it almost looks sloppy and funny. An example can be seen in a fight scene in Naruto when Naruto verses Pain in https://www.youtube.com/watch?v=mxjL6X4vZHk&ab_channel=Nintaigen.
Squash and Stretch is essential in animation but we shouldn't overuse it as seen in the example.
The reason we apply squash and stretch is to show the mass of an object, the more an object squashes indicates a softer, lighter object like a balloon while an object that doesn't stretch at all could be a bowling ball or a rock.
I also have the question about the position of an object. Is this determined based on the center of the object, and is that by extension based on a physics equation?
pixar lamp! sorry i love this animation so much as a kid.https://www.youtube.com/watch?v=PGKmexNTHNE