Editing Escuelas

From BRL-CAD

Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.

The edit can be undone. Please check the comparison below to verify that this is what you want to do, and then save the changes below to finish undoing the edit.
Latest revision Your text
Line 272: Line 272:
 
* the bullet simulation has the Y axis up, that's the vertical axis bullet considers
 
* the bullet simulation has the Y axis up, that's the vertical axis bullet considers
 
* the simulation can be downloaded from https://github.com/elf11/brlcad/tree/master/BasicDemo
 
* the simulation can be downloaded from https://github.com/elf11/brlcad/tree/master/BasicDemo
 
18th October
 
* finalized the standalone bullet demo, the files can be found here https://github.com/elf11/brlcad/tree/master/BasicDemo, now there are printed the penetration points, the depth and the normals
 
* started replicating bullets behaviour in brl-cad, for the moment more z rays are being shoot. https://github.com/elf11/brlcad/blob/master/simrt.patch
 
  
 
I HAD to remove all the external links from this page otherwise it wouldn't have got updated.
 
I HAD to remove all the external links from this page otherwise it wouldn't have got updated.
 
 
20th October
 
* a grid of ray is being shoot by the simulate command all over the XY plan, at the moment there are 6x6 rays being shot, tried with 10x10 rays but the simulation was taking way too much time a picture of what the grid looks like can be seen here https://github.com/elf11/brlcad/blob/master/grid-ray-6x6.png
 
* the code for the grid is here https://github.com/elf11/brlcad/blob/master/simulate.patch
 
* made a comparison with what bullet returns https://docs.google.com/spreadsheet/ccc?key=0AsmiuNTm7UBZdG92bV9veW1GYk8xRS1zOWpMX0ltNmc#gid=0
 
 
21st October
 
 
* tried to replicate the bullet standalone behaviour in brlcad, for that starting with getting the correct normals, started hardcoding them in the processCollision function from the simulationalgo.cpp file; last time the normals we got were (0,0,-1) we need (0, 0, 1) since the normals are from the ground plane to the cube and we want to replicate the standalone; it didn't work cause after hardcoding them we get only the first contact point, after that first contact point we don't get any more contacts between the 2 bodies which is obv wrong since the cube still falls through the gp
 
* when the first contact is being processed then no more contacts are being added, but the cube is obv falling downwards since the depth grows
 
* then tried to change the normals from the raytracing part, simrt.c file, the traverse_zray_lists() where we set up the sim_manifold strucure; it didn't work for the same reasons as before
 
* the problem is that bullet keeps an array of manifolds and points for those manifolds, the m_manifoldPtr a pointer to this array (processCollision() function in the mged files and in the standalone bullet simulation) it gets cleared and updated every step;
 
* last year student implemented its own structures for manifolds, never using the ones provided by bullet the sim_manifold struct in simulate.h; the difference is that in our processCollision function we work on 2 different structures, the bullet structure and our structure but bullet never gets the info from our structure past the first contact
 
 
TO DO : change all the sim_manifold struct uses with the native bullet manifold structure or find a way for our particular structure to be compatible with bullet's structure
 
 
TO DO : find a way to pick 4 points out of the 36 generated that cover the maximum area of the object
 
  
 
====Expected result====
 
====Expected result====
  
 
The expected result is to allow the user to apply different forces to arbitrary objects and be able to simulate as accurate as possible the real world physics. The forces will be applied using an Archer GUI command and the user will be able to visualize the transformations the object is suffering in real time. Adding these facilities to the BRL-CAD program it will give the user the possibility to simulate a real world physics through the software.
 
The expected result is to allow the user to apply different forces to arbitrary objects and be able to simulate as accurate as possible the real world physics. The forces will be applied using an Archer GUI command and the user will be able to visualize the transformations the object is suffering in real time. Adding these facilities to the BRL-CAD program it will give the user the possibility to simulate a real world physics through the software.

Please note that all contributions to BRL-CAD may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see BRL-CAD:Copyrights for details). Do not submit copyrighted work without permission!

To edit this page, please answer the question that appears below (more info):

Cancel Editing help (opens in new window)