This could be a really broad question, but if you can help me with ideas, it would be a great help to me.
I am trying to implement basic path finding algorithm in matlab. I have to create a map where the robot can navigate and also avoid obstacles and reach destination. I have the algorithm fine with me. But am struggling with the gui as I haven't used much of Gui in matlab.
This is the following idea I had.
I created a plot and just defined 4 coods for each obstacle, destination as a circle and a start point. But am stuck when I think how I can detect whether the robot has hit an obstacle or not. One way is to create the equation of line and try to see if the point ever comes to lie on it. But the movement is based ona random generated variable. Thus it is possible for the robot to cross the line and get inside the polygon.
My apologies for bein too elaborate, but can you please tell me the best way to implement this in matlab? It is mandatory to do this in matlab. Please suggest me a better and easy way to program it. Thanks in advance.
If your obstacles are all polygons you could try to use the ray casting algorithm described on the following wikipedia site.
Point in polygon algorithm
With this you should be able to determine if the robot position lies within an obstacle, or you could determine if the next movement will bring the robot into contact with the obstacle.
If you are looking for a simple algorithm that can take care of obstacles inherently i would suggest the potential fields algorithm (can get stuck in certain cases)
Potential Fields
else you can also try the A* algorithm, which is better in my opinion; Good description of A*
Related
I'm trying to make a simplified version of crazy taxi . For the first step i need to make an infinite ground . I'VE searched online but couldn't find any examples .
Can i find any example of how to do this ?
https://www.youtube.com/watch?v=rhTPxrJICVg&list=PLLH3mUGkfFCXQcNBz_FZDpqJfQlupTznd
N3K makes an infinite runner in Subway Surfers style, meaning ground coming from the back and going towards the camera.
The above link is to his tutorial series.
This is a very broad question I try to give a very simplified answer to get you going.
To create endless road you need some sort of procedural function that generates corners for your track. If you do not need to backtrack you can cook something up yourself like (in X distance turn X degrees to the right). If you do need to backtrack you need something like perlin/simplex noise that always generates the same value based on 1 or more other values. You could use total distance to get the curve in the road.
You simply keep generating the world on the fly and unload pieces of the world you don't need any more. If the player can alter the world like destroying street furniture or leaving skitmarks you need to implement a chunk system. When you backtrack and generate a cerain part of the world with your procedural function you can have permanent changes the player made in that specific part by saving and loading to the chunk. Much like Minecraft does it actually.
i am a newbie here.. please excuse me for asking a straight forward question as i did not have the right information to do so.
for my question above, can anyone help me to create various shape in matlab?
i know how to make a simple triangle, rectangle in matlab.
what i am looking for is how to create animal patterns in matlab. all i need is the boundary layer (outer layer).
like from a bird / butterfly. something like the picture below.
butterfly wing:
can anyone give me tips / links to help me.
and yes, i also did not have the coding. i am totally lost on how to make the pattern in matlab.
my real purpose was to add mesh pattern into the wings. i have the code for the mesh. all i need is the code on how to make the wing shape.
If you already have the image created by another program, you can import it to matlab using imread. If you then want to get a binary boundary, you can use im2bw.
threshold = 0.7; % you can play with this to get what you want
binary_img = im2bw(imread('PATH\TO\IMAGE.jpg'), threshold);
In matlab versions starting at 2016a there is another function called imbinarize you might want to have a look at.
As for creating patterns from scratch, as already mentioned in the comments, matlab should not be your choice. Unless, of course, you have a well defined mathematical equation or a problem solution to which becomes the boundary. For this you can look into fimplicit, fplot etc..
I am making a game in Unity that involves creatures whose animations are determined by physics. For example, to move a limb of a creature, I can apply forces to the rigidbody it's associated with. I know how to apply forces programmatically through a script to create movements, but I'd like to create more complex and organic movements and thought that I might be able to use a neural network to do this.
I'd like each of the creatures to have a distinct way of moving in the world. I'd like to first puppeteer the creatures manually using my hand (with a Leap Motion controller), and have a neural network generate new movements based on the training I did with my hand.
More concretely, my manual puppeteering setup will apply forces to the rigidbodies of the creature as I move my hand. So if I lift my finger up, the system would apply a series of upward forces to the limb that is mapped to my finger. As I am puppeteering the creature, the NN receives Vector3 forces for each of the rigidbodies. In a way this is the same task as generating a new text based on a corpus of texts, but in this case my input is forces rather than strings.
Based on that training set, is it possible for the NN to generate movements for the characters (forces to be applied to the limbs) to mimic the movements I did with my hand?
I don't have that much experience with neural networks, but am eager to learn, specifically for this project. It would be great to know about similar projects that were done in Unity, or relevant libraries I could use that would simplify the implementation. Also, please let me know if there is anything I can clarify!
Not really an answer but would not fit for comments
I'm not sure the strategy you want to apply to train your model is the right one.
I would go for reinforcement learning methods (you can check this question for more infos about it) using, for example, the distance traveled by the center of mass of the creature on the x-axis as a fitness. If this leads to weird behaviours (like this well known robot) you could, for example, think of strategies like penalizing your individuals given the distance traveled on y and z axis (still by the CoM) to try having guys that keep there CoM on the same plane.
Without knowing exactly what you want to achieve this is hard to give you more advices. Although, if you are not looking only for neural network based techniques, there is this really great paper you might want to have a look at (here is the video of their results).
I want to ask about jelly physics ( http://www.youtube.com/watch?v=I74rJFB_W1k ), where I can find some good place to start making things like that ? I want to make simulation of cars crash and I want use this jelly physics, but I can't find a lot about them. I don't want use existing physics engine, I want write my own :)
Something like what you see in the video you linked to could be accomplished with a mass-spring system. However, as you vary the number of masses and springs, keeping your spring constants the same, you will get wildly varying results. In short, mass-spring systems are not good approximations of a continuum of matter.
Typically, these sorts of animations are created using what is called the Finite Element Method (FEM). The FEM does converge to a continuum, which is nice. And although it does require a bit more know-how than a mass-spring system, it really isn't too bad. The basic idea, derived from the study of continuum mechanics, can be put this way:
Break the volume of your object up into many small pieces (elements), usually tetrahedra. Let's call the entire collection of these elements the mesh. You'll actually want to make two copies of this mesh. Label one the "rest" mesh, and the other the "world" mesh. I'll tell you why next.
For each tetrahedron in your world mesh, measure how deformed it is relative to its corresponding rest tetrahedron. The measure of how deformed it is is called "strain". This is typically accomplished by first measuring what is known as the deformation gradient (often denoted F). There are several good papers that describe how to do this. Once you have F, one very typical way to define the strain (e) is:
e = 1/2(F^T * F) - I. This is known as Green's strain. It is invariant to rotations, which makes it very convenient.
Using the properties of the material you are trying to simulate (gelatin, rubber, steel, etc.), and using the strain you measured in the step above, derive the "stress" of each tetrahdron.
For each tetrahedron, visit each node (vertex, corner, point (these all mean the same thing)) and average the area-weighted normal vectors (in the rest shape) of the three triangular faces that share that node. Multiply the tetrahedron's stress by that averaged vector, and there's the elastic force acting on that node due to the stress of that tetrahedron. Of course, each node could potentially belong to multiple tetrahedra, so you'll want to be able to sum up these forces.
Integrate! There are easy ways to do this, and hard ways. Either way, you'll want to loop over every node in your world mesh and divide its forces by its mass to determine its acceleration. The easy way to proceed from here is to:
Multiply its acceleration by some small time value dt. This gives you a change in velocity, dv.
Add dv to the node's current velocity to get a new total velocity.
Multiply that velocity by dt to get a change in position, dx.
Add dx to the node's current position to get a new position.
This approach is known as explicit forward Euler integration. You will have to use very small values of dt to get it to work without blowing up, but it is so easy to implement that it works well as a starting point.
Repeat steps 2 through 5 for as long as you want.
I've left out a lot of details and fancy extras, but hopefully you can infer a lot of what I've left out. Here is a link to some instructions I used the first time I did this. The webpage contains some useful pseudocode, as well as links to some relevant material.
http://sealab.cs.utah.edu/Courses/CS6967-F08/Project-2/
The following link is also very useful:
http://sealab.cs.utah.edu/Courses/CS6967-F08/FE-notes.pdf
This is a really fun topic, and I wish you the best of luck! If you get stuck, just drop me a comment.
That rolling jelly cube video was made with Blender, which uses the Bullet physics engine for soft body simulation. The bullet documentation in general is very sparse and for soft body dynamics almost nonexistent. You're best bet would be to read the source code.
Then write your own version ;)
Here is a page with some pretty good tutorials on it. The one you are looking for is probably in the (inverse) Kinematics and Mass & Spring Models sections.
Hint: A jelly can be seen as a 3 dimensional cloth ;-)
Also, try having a look at the search results for spring pressure soft body model - they might get you going in the right direction :-)
See this guy's page Maciej Matyka, topic of soft body
Unfortunately 2d only but might be something to start with is JellyPhysics and JellyCar
After some sample projects, I have started with my first game in cocos 2d and box 2d where objects fall from a parachute and you kill them using slingshot. Now i'm stuck # couple of things for a while:
Collision Issue:
Using Box 2d i have made collision with objects. However when i add a counter to get a count of my collision i doesn't work. Counter increases even though the percentile is moved out of the screen.Don't know how to get rid of this.
I'm trying to get random rotation to my sprites which fall from above, Like a parachute experience. Now all of then rotate # a same angle.
Lastly i need to get rid of the surrounding sprites when collision happens. Ex: When the percentile collides with a falling object, in a radius of 2.5 cms the other sprites should also disappear.
I Badly need help and suggestions, hence all the 3 questions # once :-). I have provided the link for my project so that you can look # the source code. Desperately looking for your help guys!!!
Download Source Code:
http://jumbofiles.com/6fn5mmpnq1q8/Karthik.zip.html
Budding Developer,
Karthik
You have a pretty good tutorial here: http://www.raywenderlich.com/475/how-to-create-a-simple-breakout-game-with-box2d-and-cocos2d-tutorial-part-12
I think that one can solve your problems :)
You can get the best tutorial for the particular requirement you have described over here.....
The link for that is as follows
http://www.raywenderlich.com/606/how-to-use-box2d-for-just-collision-detection-with-cocos2d-iphone
The tutorial is of 2 parts and describes the code briefly.. The code of that is described and you can get good amount of help from there.
ques 1 + 3: you need read link which share by Mikael and Marine
ques 2: in cocos2d, if you want get random value, you can use support function (such as: rand(), random(), CCRANDOM_0_1() ....)... i think, you need set rotation value for object. i dont know your problem, you need explain it (link is "File Not Found or Deleted / Disabled due to inactivity or DMCA")