----------------------------------- Saad Tue Jun 17, 2008 12:13 pm Prysx, Grade 12 Final Project ----------------------------------- For my summative project, I made Prysx, which is a particle and rigid body physics engine put together. This is a demo I put together. The graphics engine uses OpenGL, and for window management SDL was used. CONTROLS: If your drawing a polygon Right click stops the drawing of polygon Left click to set the starting point and left click to set the final radius at your targeted radius If point is on a polygon Middle click breaks apart the polygon Or else Left click spawns particles Right click pulls the particles towards the mouse Middle clicks blows them away from the mouse Enjoy Edit: Use ----------------------------------- Aziz Tue Jun 17, 2008 12:32 pm RE:Prysx, Grade 12 Final Project ----------------------------------- Is sweet. You know my views about it, I'll post the gist of suggestions for others: - Colors - Option to take of side boundaries - Force of attraction/unattraction proportional to distance I'm having fun with it (great distraction at work!) ----------------------------------- Euphoracle Tue Jun 17, 2008 3:52 pm RE:Prysx, Grade 12 Final Project ----------------------------------- Ooo, pretty and fun. I like it. Too bad my school doesn't let us do anything cool like this to show off a bit for our projects ): ----------------------------------- apomb Tue Jun 17, 2008 3:59 pm RE:Prysx, Grade 12 Final Project ----------------------------------- Congrats on getting all the bugs worked out. Its very nice. ----------------------------------- Dan Tue Jun 17, 2008 5:19 pm RE:Prysx, Grade 12 Final Project ----------------------------------- Very nice and for the linux fans out there, the exe seems to run fine threw WINE if you don't want to complie it. ----------------------------------- Euphoracle Tue Jun 17, 2008 6:47 pm RE:Prysx, Grade 12 Final Project ----------------------------------- Saad is more pro at cross compatibility than most commercial identities, so it seems (: ----------------------------------- CodeMonkey2000 Tue Jun 17, 2008 7:09 pm RE:Prysx, Grade 12 Final Project ----------------------------------- Saad, what's your secret to blurring? ----------------------------------- zylum Tue Jun 17, 2008 7:11 pm RE:Prysx, Grade 12 Final Project ----------------------------------- Pretty nice! I see you only used convex polygons so I'm assuming you used the separating line theorem for collision detection? If not, can you briefly describe your method? I'm writing a physics engine as well but with arbitrary polygons so I'm using a different method (SLT doesn't work with concave polys). ----------------------------------- Saad Tue Jun 17, 2008 7:16 pm Re: RE:Prysx, Grade 12 Final Project ----------------------------------- Saad, what's your secret to blurring? No secret, basically drawing random lines over the current graphics. (Its in Main.cpp should you want to look around). Pretty nice! I see you only used convex polygons so I'm assuming you used the separating line theorem for collision detection? If not, can you briefly describe your method? I'm writing a physics engine as well but with arbitrary polygons so I'm using a different method (SLT doesn't work with concave polys). I did use convex polygons and separating axis theorem. However should you want to use concave and separating axis theorm, I recommend splitting the polygons into convex polygons. You can achieve this by triangulating the polygons and joining up those triangles that that create convex polygons to create smaller convex polygons. Now you test each of those smaller polygons for collision (Should any collide then you have a collision). I also think you could test it by using intersections of each line its up to you Edit: Just to say one thing about the collision. It is not perfect right now and the collision doesn't work with polygons that have the same axis (polygons with even number edges, a square has 2 of the same axis). This is why if you noticed the polygon sides was always odd ;). Perhaps some input? ----------------------------------- Reality Check Tue Jun 17, 2008 8:52 pm Re: Prysx, Grade 12 Final Project ----------------------------------- Awesome dude. It's great that you guys did C++ in grade 12 though! ----------------------------------- zylum Wed Jun 18, 2008 1:10 am RE:Prysx, Grade 12 Final Project ----------------------------------- I was wondering which method would be faster as they are both O(n*m). Also they both have very simple loops with few calculations. Though SAT quits when it finds that two polygons aren't intersecting and line intersections quits when it does find an intersection. Typically, it is more likely that two polygons are not intersecting but how much complexity would be added for concave polygons? ----------------------------------- md Wed Jun 18, 2008 10:34 am RE:Prysx, Grade 12 Final Project ----------------------------------- This is pretty cool! ----------------------------------- Saad Wed Jun 18, 2008 10:53 am Re: RE:Prysx, Grade 12 Final Project ----------------------------------- I was wondering which method would be faster as they are both O(n*m). Also they both have very simple loops with few calculations. Though SAT quits when it finds that two polygons aren't intersecting and line intersections quits when it does find an intersection. Typically, it is more likely that two polygons are not intersecting but how much complexity would be added for concave polygons? For concave polygons you will be testing for which of the convex polygons, but I would go with SAT since it wouldn't check some edges that have no need to be checked. Also SAT would let you project your edges with velocities which makes it much easier find if they'll collide in a frame or not aswell as give you collision normals and translation vectors so that they don't collide. And thanks all for the great comments :) ----------------------------------- corriep Sun Jan 25, 2009 9:21 pm RE:Prysx, Grade 12 Final Project ----------------------------------- The link doesn't work for me :( ----------------------------------- saltpro15 Sun Jan 25, 2009 9:23 pm RE:Prysx, Grade 12 Final Project ----------------------------------- bad necro paul! ----------------------------------- Saad Sun Jan 25, 2009 9:34 pm Re: RE:Prysx, Grade 12 Final Project ----------------------------------- The link doesn't work for me :( Ah sorry, I renamed the file before and forgot to change my post. Link works now, enjoy :) ----------------------------------- Homer_simpson Mon Jan 26, 2009 2:02 am Re: Prysx, Grade 12 Final Project ----------------------------------- very nice! nice motion blur btw :D question: how does the polygon break ----------------------------------- saltpro15 Mon Jan 26, 2009 10:37 am RE:Prysx, Grade 12 Final Project ----------------------------------- question : why does the command prompt open when I run it? awesome game btw ----------------------------------- ecookman Mon Jan 26, 2009 1:41 pm RE:Prysx, Grade 12 Final Project ----------------------------------- coolest.thing.ever ----------------------------------- Saad Mon Jan 26, 2009 2:44 pm Re: Prysx, Grade 12 Final Project ----------------------------------- very nice! nice motion blur btw :D question: how does the polygon break All of the polygons are composed of triangles, and so when they are created they are triangulated (via the ear clipping algorithm). When I want to break a polygon, each of the triangles become a separate polygon, and those get recursively subdivided into smaller triangles until an arbitrary depth is reached, which was just 1 for this demo, but if you want you can have it it subdivide much deeper and get a lot more triangles. question why does the command prompt open when I run it? awesome game btw I used the command prompt to output debugging information but SDL didn't output directly to the console, and so I recompiled SDL so that it output to the console. Unfortunately I didn't have the time to recompile the source for Prysx with the original library and so the console shows.