Ok. As promised, later than expected, here’s all the math and logic that goes into making these extensions! The reason for this is so you guys can get a better understanding of how to use the extensions at their fullest, and I hope all this in general is useful to some of you!
Softbodies
This extension is used for primarily 1-demensional rope physics.
The main creation block makes an array from an already existing sprite, meaning it duplicates that sprite. that’s why when you create a new rope, the source sprite is still left behind.
In this extension there are two different types of rendering:
- Fill rendering
- Takes the width of each segment image and connects all the edges to make a unified outline-fill.
- Line Rendering
- Simply draws lines between each segment
Both rendering styles can be used on sprite’s image or standalone image. Using the block that renders on a sprite’s image is useful because maybe there’s camera movement involved and we want the canvas to the given softbody to move with it.
The math I use for keeping the segments together is Verlet Integration, Hooke’s Law springs, and simple constrain projection. I have 4 blocks for changing the spring forces currently maybe to add more in the future:
- Set Max Stretch
- Changes how far apart each segment is allowed to be from each other
- Set Segment Max Velocity
- Changes how fast segments are allowed to travel
- Set Spring Stiffness
- Changes how aggressive position error is corrected
- Set Damping
- Changes how fast the velocity is reduced
There are also a few blocks on query that make finding segments/softbodies easier.
And that’s it for this extension!
Inverse Kinematics
The type of integration I use for this extension is FABRIC (Forward And Backward Reaching Inverse Kinematics).
That link is a video, and I think it explains it pretty well.
Like the video said, the physics is iterative, meaning the position of each of the joints is calculated by the other joints’ positions, so no velocity here.
I’m planning on adding blocks for angle clamping.
I made this extension a while back and haven’t really touched it sense. I’m up to suggestions about this extension, what might be cool add-ons, what could be changed?
That’s it for this extension!
Ragdoll Physics
This extension is better if you want to get down to the structure of your softbody.
It’s like the softbody extension, it has similar math, but in this extension you make your own connections from sprites.
This is better for making 2-dimensional softbodies.
This extension is fairly new. I haven’t done really anything with it besides create the core idea.
In the near future, I will add blocks similar to that of the softbody extension (for changing the physics)
Although it’s like the softbody extension, there’s no way right now to define all the sprites that are connected to a given sprite; there’s no array’s involved as your making the single connections yourself.
That’s it!
Line Canvas
This extension basically makes a new image that stays in-between two sprites and draws a line between them.
What’s happening is a new canvas sprite is created and its width and height change based on the x and y differences between the two sprites you chose. Its width and height change every frame.
I might add more to this extension, but for right now it’s just a nice little function if you don’t want to do all the math for drawing a line from two points!
I meant to put this in my first post, but here’s the topic this extension really got out:
Link
Continuous Rotation
This extension is great for procedural animation in the image processing sense, because there’s no physics involved. This extension is for rotating images.
The reason I created this extension is because I wanted to animate a spinning effect on one of my sprites so that it would face another sprite. I was trying to make a game where you put skeletal bones together to make a creature of some kind. Although I didn’t end up finishing that game, I came up with a cool idea that had many applications.
I used this extension in one of my games for this topic, where I set each of the segments in a softbody to rotate continuously towards one another (which is totally doable!)
Along with being able to keep a sprite rotating towards another sprite, this extension can simply be used to rotate a standalone image towards a point.
That is it for this extension!
Thank you everybody for participating and I hope this post is of some use!
Also, I would love some suggestions to the IK extension and Ragdoll extension because they need some work! Any suggestions or thoughts are welcome as always.