hobogoblin

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About hobogoblin

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  1. Calculating pressure transfer between pipes

    An assumptionb of an incompressible gas is pretty much standard for this sort of thing.
  2. Optimisation of core code

    I've use the profiler in vs a bit, and I've used codexl for opengl debugging, but the only thing I could make from it was"here's where your method is spending the most time" which stops being helpful. Can I look at cache hits or Misses? That's pretty much the only other thing I'm aware I should be optimising for. I'm not too concerned about x platform (although my code does work on mac as well, not tested on Linux) but I'm most familiar with windows as a dev environment, so I'd like to start here. I've come across vtune before but figure it's not gonna tell me anymore than the vs profiler with my current level of knowledge.
  3. I have a 3D physics engine, which has a couple of performance critical sections (broadphAse collision detection, narrowphase detection and collision response). I've pushed them quite far (as far as possible from an algorithmic standpoint) and would like to try and extract just a little more out of all the systems. I would like to start looking at the likes of cache misses and cache hits in the program , in specific sections. Using visual studio (professional) how would I g o about detecting these things, and trying to optimise my methods? Note that I know there are better ways to get performance boosts, however this is a leaning exercise.
  4. codeblock and andoird

    What libraries/frameworks are you using? Are you developing in Java or c++? All code blocks is is an IDE (really a beefy text editor) so you need to set it up to work with whatever language or tools you want.
  5. It comes with a makefile. You need the gnu tools (http://gnuwin32.sourceforge.net/), and just open a command prompt in the same directory as the makefile and type make glew.lib See the instructions (http://glew.sourceforge.net/build.html)   For the headers, either put them in a default search directory, or add the GL folder to your include paths by the -I command with gcc, or by adding them to your project in whatever IDE you're using. For code blocks: Settings -> Compiler & Debugger Settings -> Search Directories. For VS it's C++->General->Additional Include Directories.
  6. Collision detection for two cubes (3D)

    Actually... that's all there is in a physics engine. I assume you mean you have a broadphase method, and are now working on a narrowphase/exact detection, followed by responses. It's tricky to do right, and checking edge-Edge collisions is going to get unwieldy very quickly. I'd strongly suggest you look at either the Seperating Axis Test, or the GJK algorithm. Note that once you get a boolean collision response, you need to know the collision points and penetration depth. Dealing with multiple colliding bodies is another pain, as is friction. You are only scratching the surface of this.
  7. OpenGL Assets for tech demos

      Well, currently, I think it's more important for me to demonstrate what I know. I'm not interested in spending months working on my 3D modelling skills, followed by Photoshop skills so I can spend hours creating assets for demos, etc. I'd much rather specialize in what I'm working in currently, and spend my 10,000 hours working towards stuff that I could use every day, such as ambient occlusion, environment rendering, simulating rain, lens flare effects, and I'm not even going to keep going to be honest. Sure, I need to know these things, but me being a good 3D modeller isn't going to improve how good I am at writing an efficient renderer for it, or implementing dynamic illumination effects.
  8. OpenGL Assets for tech demos

    That last asset is awesome, however I currently have nothing that would go well with him. I guess I could texture my water as lava, and try find a dark skybox, but I'd like a nice backdrop for him, he would make a cool scene.    As an aside, is there anywhere I can download animations that I can import into max for a rigged biped character?
  9. OpenGL Assets for tech demos

    Fair enough, thought it was worth asking. I'll stick to what I get on that site so.   Cheers.
  10. OpenGL Assets for tech demos

    They're awesome. I assume I'm free to use them? I can't find any licensing info on the site. I came across tf3dm.com too, but a lot of the models seem to be ripped from games, is it cool to use that stuff? and if it is, do you know how I'd go about extracting some other assets from games I own?
  11. OpenGL Debugging Graphics

    AMD have CodeXL aswell, it's a visual studio addin, lets you debug your OpenGL states as though you are using the VS debugger(almost). Really helpful. Aside from that, I have a checkError function that if I create  a debug build (no optimisations) it will call glGetError and log the results with a timestamp and a little information about where it was called, what the state of the program at that point was. I sprinkle it liberally around problem errors, and run my app for a little while, and parse my logs after. I normally write it to a stringstream and on calling the destructor for the singleton I dump the stringstream to a file, formatted.
  12. Hey all, a question for you; I'm just finished in Uni, and I really enjoyed the classes I took in OpenGL, and have some nice demos of lighting effects, dynamic cubemapping, volumetric shadows, global illumination, deferred rendering, and a few more topics, and I'm currently looking to get employed in this area, however I'm a really crap artist. I'm looking to put together a kind of demo reel where I show what I've done to send out with my CV, but the assets that I'm using in my demos at the minute look awful (most of them are implemented with one crate texture, a brick texture, a rigged human supplied to me by my university, and a checkerboard texture) and to be honest I'm not happy putting together my work like this. I was wondering if anyone here would be able to point me in the direction of some Hi-Quality 3D meshes and textures that I can use for non-commercial purposes? I'd be happiest with some items that I can attribute the author for (Creative commons I think?) as the source code will be shared too, so the authors will receive full credit in all of the readmes and in the video.   I've tried turbosquid, but the stuff just looks like garbage most of the time. I like the idea of taking some assets from games I've been playing, but I'm not sure of the legality of it, or even how I would go about extracting assets from games.   Regarding formats, I have a custom loader for every format under the sun (except .MAX but I can re-export as FBX) so I don't care/   Hope you can help!
  13. Fracture physics

    Would you believe, in 5 years of academia, I've never actually thought of asking an author for advice on it! (Seriously!) I'll give it a try, however the author probably has a vested interest in not having a competing engine existing, as he is actually involved in the DMM engine (the first paper linked) but I'll ask nonetheless Hey, thanks for te input. I'm looking for in engine fractures to be honest, and it's less about the end result , and more about the process of actually doing it myself however I'm a bit stuck. I've actually linked to two papers which cover I in real time, the problem with looking at physics papers is they tend to cover FEA methods, which are offline computations, so I'm really looking at siggraph and theikes for papers. I can find a multitude of papers on the topic, but no examples of it runnin other than DMM.
  14. Fracture physics

    Hi, I've been working on a 3D rigid body engine for the past while as a pet project, and so far I'm happy with how it runs. I've got a world that responds correctly to collisions between convex rigid bodies, using GJK w/EPA and the sequential impulses method.   The next step I would like to take is to implement some fracture simulations into the engine, but I've hit a bit of a brick wall. Research and reading first came up with http://graphics.berkeley.edu/papers/Parker-RTD-2009-08/Parker-RTD-2009-08.pdf which is a paper on how the DMM (Digital Molecular Matter) engine works, which is far more advanced than I'm aiming for currently.   I went down the rabbit hole, and ended up back in 1999 at this paper: http://graphics.berkeley.edu/papers/Obrien-GMA-1999-08/(which it seems is the basis for the DMM engine anyway, with some modifications).   I'm trying to implement this method, however am struggling with it. Has anyone here any experience with this topic, or does anyone know of an implementation of this (or a similar paper) that I could use to get started?