/sci/ - Science & Math » Thread #13300096

7KiB, 301x300, images.jpg

View Same Google iqdb SauceNAO

on rigidbody???

Anonymous Sun 20 Jun 08:41:06 2021 No.13300096 View Reply Original Report

Quoted By: >>13300118 >>13300163 >>13300183 >>13300281 >>13300417 >>13302699 >>13303134

looking on mathemathical models where i can use bunch of coordinates as pcitured and group them into one unit and stops/detects when object is outside it or inside it, what do i do.

Anonymous

Anonymous Sun 20 Jun 2021 09:05:46 No.13300118 Report

Quoted By: >>13300128

>>13300096
Honestly if I understand your question properly the best solution is to write a program in C++ or python. Jupyter notebook is great for this kind of stuff if you want to visualise it.
You just need to write the equation for each plane and then the condition is that your coordinate is under one plane and under another and to the left of one and to the right of another and above another etc.

Anonymous

Anonymous Sun 20 Jun 2021 09:11:44 No.13300128 Report

Quoted By: >>13300166

>>13300118
>jupiter notebook
https://jupyter.org/ this???
>equation
Yes, what equation exactly? how do you write to the left or right of one?

Anonymous

Anonymous Sun 20 Jun 2021 09:29:41 No.13300163 Report

Quoted By: >>13300172 >>13300408

>>13300096
What have you tried?

Anonymous

Anonymous Sun 20 Jun 2021 09:31:25 No.13300166 Report

Quoted By: >>13300172

>>13300128
>https://jupyter.org/ this???
Yes this. Anaconda is great.
>what equation exactly?
The equation of each plane.
>how do you write to the left or right of one?
Well it depends on the plane. If the plane intersects the Z axis at some point then just use above or below it. If it doesn't intersect Z then just write the condition as above or below a line on the XY plane.

Anonymous

Anonymous Sun 20 Jun 2021 09:33:15 No.13300172 Report

Quoted By: >>13300191 >>13300739

>>13300163
google? lol
>serious note
dunno, havent been able to find related links to this. I thought it should be a bunch of arrays and coordinates like inside an fbx but that shit is too vague.

>>13300166
hmmm, what would be the equation exactly. This looks confusing...

Anonymous

Anonymous Sun 20 Jun 2021 09:38:04 No.13300183 Report

Quoted By: >>13300239

>>13300096
Convex hull +collision detection. Come on OP this is literally first year stuff

Anonymous

Anonymous Sun 20 Jun 2021 09:41:22 No.13300191 Report

Quoted By: >>13300239

>>13300172
>what would be the equation exactly. This looks confusing...
The equation of a plane?

Anonymous

Anonymous Sun 20 Jun 2021 09:56:49 No.13300221 Report

Quoted By: >>13300239

Any progress?

Anonymous

Anonymous Sun 20 Jun 2021 10:03:24 No.13300239 Report

Quoted By: >>13300244 >>13300275 >>13300303

>>13300183
our first year spent on dumb shit like codin on unity. pls dont say anymore.
>convex hull
so? do you just put in a bunch coordinates and voila?

>>13300191
>equation of a plane
huh??? like the equation of a circle?
d2=x2+y2???
>>13300221
pretty good. i think i ll drop 3d completely heh

Anonymous

Anonymous Sun 20 Jun 2021 10:06:08 No.13300244 Report

Quoted By: >>13300294

>>13300239
Are you Indian? How can you be this stupid? You have literally no agency to read up on the problem and solve it.

Just give up and go do something like webdev.

Anonymous

Anonymous Sun 20 Jun 2021 10:17:37 No.13300258 Report

Quoted By: >>13300294

Take a point $(x_0, y_0, z_0)$ on one of the faces and let $(a, b, c)$ be a vector perpendicular to the plane. For any point $(x, y, z)$ on the plane, the vector $(x -x_0, y-y_0, z- z_0)$ lies on the plane and is hence perpendicular to $(a, b, c)$ , so it satisfies the relation $a(x - x_0) + c(y - y_0) + c(z - z_0) = 0$ , which is the equation of the plane. This plane partitions the space into two connected components which are described by the inequalities $a(x - x_0) + c(y - y_0) + c(z - z_0) > 0$ (the set of points not on the plane and lying in the half-space pointed to by the vector $(a, b, c)$ and $a(x - x_0) + c(y - y_0) + c(z - z_0) < 0$ (the other half-space). Your region is just the intersection of a collection of such half-spaces, so it would be described by a collection of inequalities of the form $a_i(x - x_{0, i}) + b_i(y - y_{0, i}) + c_i(z - z_{0, i}) < 0$ for i = 1, ..., M, where M is the number of faces.

Anonymous

Anonymous Sun 20 Jun 2021 10:21:53 No.13300263 Report

Quoted By:

please ignore this retard and his threads

Anonymous

View Same Google iqdb SauceNAO exampleWithFourSimplePlanes.png, 196KiB, 953x819

Anonymous Sun 20 Jun 2021 10:26:40 No.13300275 Report

Quoted By: >>13300290 >>13300294 >>13300297 >>13300326

>>13300239
>>equation of a plane
>huh??? like the equation of a circle?
Uhhh yeah dude. Like the equation of a circle. Or the equation of a sphere. Like a fucking equation wtf.
Anyway, I made you an example, but maybe you are thinking on a higher level here, and aren't really interested in the basic stuff.

Anonymous

Anonymous Sun 20 Jun 2021 10:29:52 No.13300281 Report

Quoted By: >>13300294

>>13300096
the vector to the closest centroid to the point points below the plane.

Anonymous

Anonymous Sun 20 Jun 2021 10:33:12 No.13300290 Report

Quoted By: >>13300326

>>13300275
Anyway, in case you are at all interested, here there are 50000 points created in the rectangle, but only the ones that are inside the shape defined by 4 planes are drawn.
I think the code is pretty self-explanatory.
The planes are deliberately simple, but in general you can usually think of a plane as z=ax+by+c, or you can always define it as ax+by+cz+d =0. Like the equation of a circle
Good luck.

Anonymous

Anonymous Sun 20 Jun 2021 10:34:56 No.13300294 Report

Quoted By: >>13300301 >>13300313 >>13300321

>>13300244
>indian
sort off
>>13300258
ah... so by writing
relation a(x?x0)+c(y?y0)+c(z?z0)=0
anything less or more means its not on the plane huh?
>>13300275
this is very complex...
Idk, i know only equation d2=x2+y2+z2 and sort of it. are they the same? how do you derive a plane from it? following this common convention?

>>13300281
what?

Anonymous

Anonymous Sun 20 Jun 2021 10:35:42 No.13300297 Report

Quoted By: >>13300326 >>13300328

>>13300275
Pretty terrible as a general solution. But anyway unity has both convex hull and collission detection wrappers. So does scipy if you want to keep it pure Python.

Anonymous

View Same Google iqdb SauceNAO kek.jpg, 19KiB, 413x395

Anonymous Sun 20 Jun 2021 10:36:59 No.13300301 Report

Quoted By:

>>13300294
>sort off

Anonymous

Anonymous Sun 20 Jun 2021 10:37:34 No.13300303 Report

Quoted By: >>13300323 >>13300326

>>13300239
>i think i ll drop 3d completely
Please do. You're a huge faggot who can't read up on a subject by himself, you are clearly incapable of understanding even basic stuff, you keep spamming this board and you're most likely underage. Nobody wants you here and you should just try to get a job in a call center.

Anonymous

Anonymous Sun 20 Jun 2021 10:39:38 No.13300313 Report

Quoted By: >>13300335

>>13300294
>relation a(x?x0)+c(y?y0)+c(z?z0)=0
>anything less or more means its not on the plane huh?
Yes, a(x?x0)+c(y?y0)+c(z?z0)=0 describes exactly the points on the plane, so if a point is not in this plane you must have either a(x?x0)+c(y?y0)+c(z?z0) < 0 or a(x?x0)+c(y?y0)+c(z?z0) > 0, which are the inequalities describing the two half-spaces. For more information, you should look into elementary coordinate geometry.

Anonymous

Anonymous Sun 20 Jun 2021 10:41:44 No.13300321 Report

Quoted By: >>13300335

>>13300294
>what?
consider the OP, every triangle represents a surface with its own normal, a plane. every one has a centroid and a normal to that centroid.
a point will always be closet to at least one centroid.
at a point, the vector from the centroid to that point will either be above the surface or below it.
There are a few ways to calculate that.

Anonymous

Anonymous Sun 20 Jun 2021 10:42:19 No.13300323 Report

Quoted By:

>>13300303
>spamming
I would agree with you but the other threads on the board are terrible too

Anonymous

Anonymous Sun 20 Jun 2021 10:43:18 No.13300326 Report

Quoted By: >>13300330 >>13300333

>>13300275
>>13300297
actually im rrally looking for something simple like...pure math like, involving only additions/negation(?) and multiplications/divition operations between xyz coordinate i guess
so my data can only involve x, y , z... and i dont even understand w in xyzw... i hope to make a solid decent 3d game from this somehow.

>>13300290
i see... then naturally i need only one coordinates or given my data.
>z=ax+by+c
ok does this by plane works in rotated too? or does it have to face the floor that is 0,0,0
>>13300303
i am working at call center alr lel

Anonymous

Anonymous Sun 20 Jun 2021 10:44:17 No.13300328 Report

Quoted By:

>>13300297
Yeah it is but I enjoyed making a little shape.
Also OP doesn't have a concept of the equation of a plane so maybe it's a good starting point I dunno.

Anonymous

Anonymous Sun 20 Jun 2021 10:45:19 No.13300330 Report

Quoted By: >>13300343

>>13300326
>ok does this by plane works in rotated too?
What?

Anonymous

Anonymous Sun 20 Jun 2021 10:46:19 No.13300333 Report

Quoted By: >>13300343 >>13300361

>>13300326
Wait are you the one who keeps asking stupid questions about 3d projection and why do we need matrices?

Anonymous

Anonymous Sun 20 Jun 2021 10:46:33 No.13300335 Report

Quoted By: >>13300345

>>13300313
im pretty sure we didnt get that at elementary
>x-x0
so does this work for say 4 coordinate? like a square?

>>13300321
oh i see...
I ll keep that in mind. it might be too advanced for my use.

Anonymous

View Same Google iqdb SauceNAO images (5).png, 13KiB, 510x601

Anonymous Sun 20 Jun 2021 10:49:00 No.13300343 Report

Quoted By: >>13300356

>>13300330
yes maybe like picture.
what are the coordinates of the plane or is this located in the model space of sort?

>>13300333
dunno. you are the smart one. u tell me

Anonymous

Anonymous Sun 20 Jun 2021 10:49:30 No.13300345 Report

Quoted By: >>13300363

>>13300335
>so does this work for say 4 coordinate? like a square?
Yes, assuming I'm understanding your question correctly.
>we didnt get that at elementary
Just look for textbooks/notes/lectures on the topic, you'll find plenty.

Anonymous

Anonymous Sun 20 Jun 2021 10:55:38 No.13300356 Report

Quoted By:

>>13300343
Good luck.

Anonymous

Anonymous Sun 20 Jun 2021 10:56:49 No.13300361 Report

Quoted By: >>13300366

>>13300333
He is, he's been at it for days, and you fucks keep posting in his threads without saging

Anonymous

View Same Google iqdb SauceNAO Screenshot_2021-06-20-17-53-58-26.jpg, 312KiB, 720x1141

Anonymous Sun 20 Jun 2021 10:57:09 No.13300363 Report

Quoted By: >>13300368 >>13300372

>>13300345
>coordinate geometry
google gave me this somehow.

>four coordinates
is this provable? does (0,0,1) stands above (0,0,0) with that equation?

Anonymous

Anonymous Sun 20 Jun 2021 10:58:12 No.13300366 Report

Quoted By:

>>13300361
this is not about matrices isnt it?
pls dont confuse me

Anonymous

Anonymous Sun 20 Jun 2021 10:59:23 No.13300368 Report

Quoted By: >>13300372

>>13300363
>does (0,0,1) stands above (0,0,0) with that equation?
It makes no sense to say that a point is above some other point

Anonymous

Anonymous Sun 20 Jun 2021 11:00:48 No.13300372 Report

Quoted By: >>13300407

>>13300363
>>13300368
I mean, to talk about such relations between points, you'll also have to refer to a plane and an orientation of that plane.

Anonymous

Anonymous Sun 20 Jun 2021 11:18:01 No.13300407 Report

Quoted By:

>>13300372
how do i acquire the orientation of plane? it s like normal right?

Anonymous

View Same Google iqdb SauceNAO 1623084594018.jpg, 399KiB, 1835x1428

Anonymous Sun 20 Jun 2021 11:18:54 No.13300408 Report

Quoted By: >>13300438 >>13300598 >>13302679

>>13300163
>What have you tried?
spamming threads
seriously, this is like the 100th thread over the past month.
OPs MO is to spam 6 threads across several boards at once, then proceed to be a retard
seriously, there is no reason to reply to this thread
it's pissing into the wind

Anonymous

Anonymous Sun 20 Jun 2021 11:23:07 No.13300417 Report

Quoted By:

>>13300096
This is part of what discrete geometry does.
To my knowledge, Matousek from ETH Zurich wrote a textbook on it (and much more topics).
I think that getting familiar with linear programming would also give you the necessary knowledge, but with less effort.
(also, this is not very hard, it's just a system of linear inequalities)

Anonymous

Anonymous Sun 20 Jun 2021 11:35:45 No.13300438 Report

Quoted By:

>>13300408
>no reason to reply to you then its not like theres any good information from you
>also arent you just spamming the same shits about the same thing? should ban you for a year

Anonymous

Anonymous Sun 20 Jun 2021 12:42:31 No.13300598 Report

Quoted By:

>>13300408
snu snu

Anonymous

Anonymous Sun 20 Jun 2021 13:48:59 No.13300739 Report

Quoted By:

>>13300172
>google? lol
But have you actually tried a programming language yet

Anonymous

Anonymous Sun 20 Jun 2021 22:14:05 No.13302679 Report

Quoted By:

>>13300408
roll

Anonymous

View Same Google iqdb SauceNAO 8CD88237-37EE-4EDE-8FC4-349E78CA (...).gif, 1MiB, 225x326

Anonymous Sun 20 Jun 2021 22:19:02 No.13302699 Report

Quoted By:

>>13300096
Are you the guy that wanted to do 3D projection but refused to learn how matrices work?

Anonymous

Anonymous Mon 21 Jun 2021 01:02:15 No.13303134 Report

Quoted By:

>>13300096
not sure what you want to do? you want to detect clusters?

Capcode	All Only User Posts Only Moderator Posts Only Admin Posts Only Developer Posts
Show Posts	All Only With Images Only Without Images
Deleted Posts	All Only Deleted Posts Only Non-Deleted Posts
Ghost Posts	All Only Ghost Posts Only Non-Ghost Posts
Post Type	All Only Sticky Threads Only Opening Posts Only Reply Posts
Results	All Grouped By Threads
Order	Latest Posts First Oldest Posts First

Your latest searches