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Julien Bayle

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Everything posted by Julien Bayle

  1. Hi there, I'd like to understand how this light diffusion effect is done Each light seems to influence the "space" It seems there is a kind of diffusion. I firstly thought about a kind of open-cubes based grid with transparent faces but which would reflect or distort those lights or whatever. Not sure. Thought about fog too. Would someone have some leads to dig this ? Any kind of leads would be appreciate.
  2. Julien Bayle

    Light sources lighting volumic matter?

    I got the thing to avoid sudden change But I'm still suprised by the strange light effect in the video linked finally, maybe it is a bit more complex (for me)
  3. Julien Bayle

    Little Hello

    Hi there, I'm new here. i'm basically a digital artist & technology evangelist. You can find my website here I'm currently designing a visual & sounds performance & composition system using Max6 framework. Because it uses basically openGL, i'm here to discuss about cpu strategies & view frustum culling & how to make glowing objects diffusing a nice light "around" them and other strangeness I have in mind for my system I hope we'll discuss soon, I'll begin to post in few hours. Best, Julien
  4. Julien Bayle

    Light sources lighting volumic matter?

    Hello dpadam450, sorry for the late reply. Thanks for your answer. I got you about that. About the influence of space, I cannot understand how it works. Indeed, these 2D textures are "only" 2D and if I pass through with the camera, how should it behave ? Wouldn't it be only like if you passed through a wall ..?
  5. Hi there, I tried a little presentation of myself here: http://www.gamedev.n...1-little-hello/ I wanted to describe a bit my project before posting some questions. myUniverse is a 3d visual & sound environment for composition and performance. It is all based on Max6 framework. The basic idea is to explore relationship between space & time, between visuals & sounds. I can instantiate objects in this 3d space. Each object have sounds & visuals properties. The camera visit the space and experience sounds & visuals during the travel. A core made using JAVA instantiated inside Max6 is the centralize way to store/load my maps (a map is a set of objects and their properties, plus some global context stuff like fog presence or not etc) I'm at the point when I need to : - consolidate the engine (view frustum culling based on azimuth/elevation/distance, improvement of azimuth, elevation & distance calculations..) - finish the small gui which helps me to compose (= create, move objects, change their properties etc) - design my set of objects Beginning to post here, because it seems the appropriate place for me. Feel free to tell me I should post elsewhere. Best
  6. [color=#000000][font=Arial,]I have a camera quaternion (a,b,c,d) and a cam position (camX, camY, camZ) I have an object with 3d coordinates (x,y,z)[/font] [color=#000000][font=Arial,]I need to calculate azimuth, elevation of objects relatively to the cam view direction & plane.[/font] [color=#000000][font=Arial,]First question If I keep the object in center of my view (I mean, if I aim at it with my cam), even If I rotate the cam, translate it keeping the object in the center, I should have the same azimuth value, right ?? I don't have that.[/font] [color=#000000][font=Arial,]Second question, the calculation. I'm doing (object coordinates - cam position), in order to translate the object to the cam. I'm taking the resulting coordinates and make the sandwich product with the quaternion and its conjugate. (I followed this for the pseudo code :http://fr.wikipedia....ns_l'espace)[/font] [color=#000000][font=Arial,]Then, I have a vector result and I take X & Z component and calculate the atan2.[/font] [color=#000000][font=Arial,]Does it seem right ?[/font] [color=#000000][font=Arial,]any leads or explanation would help me a lot in my struggle[/font]
  7. I understood all the point maybe it means I'm not that a beginner ok for the 2 model per object. I also got it. I also got the pure culling concept you developed. I'm already making azimuth/elevation calculation for all objects because I need these values for sound panning purpose. Does it make sense to cull or not according to these values instead of detecting intersections between objects & view planes ? Indeed, I feel it like more efficient to use these already available values in my system... My objects would/will be almost only primitives like spheres, glowing lines, very light grid of small spheres.. but glowing, lighting, flashing. many thanks for your answer. I'll implement that as soon as I'll be totally ok with that : http://www.gamedev.net/topic/626839-quaternion-rotation-vs-euler-angles-based-rotation/ This also shows you I'm a beginner
  8. [color=#3C3C3C][font=proxima-nova-1, proxima-nova-2, arial, sans-serif] hi there, I have been pointed to view-frustum culling as a nice strategy of objects activation/inactivation. Indeed, each object outside the view-frustum can be inactivated, cooling the cpu ... I worked a lot about that,more because it was unfamiliar to me than because it is really hard, and at 80% of the walk, I had doubts about the benefits of this technique considering: - I have glowing objects which HAVE to ... glow everywhere around my cam even if not directly visible. - I need a far far-clip (not 1000000, but I mean, more than the usual 200) - I already calculating azimuth / elevation of my objects relatively to my cam for sound purposes The first statement would drive me to consider a culling angle smaller than (360° - lens Angle) and even ... maybe, if an object would be behind, it would have to light the stuff in front of the cam... How would you handle this ? Does my discourse make sense ? The second one is also a cons arguments considering the view frustum culling technique. I read a lot that far far-clip of course decrease the ratio benefits/cost. The third could drive me to use those value to make almost the same thing than view frustum technique, considering all my objects that have to be culled are spherical (homogeneous dimension I mean) Indeed, I need that for sounds, so EACH objects know about its azimuth/elevation relatively to the cam. I can easily use them to inactive objects in a particular space quadrant of the cam local space for instance.. I'd like to have your opinions, maybe some leads around all of that. Best regards, Julien[/font]
  9. still multiplying quaternions and vectors... #poetry
  10. Julien Bayle

    Quaternion rotation VS Euler angles based rotation

    Alvaro, I got it. and this is directly related to my mistake! I'm using Max6 and I have to implement that. I guess all objects required already exist but I'm a bit confuse with these incremental rotations (reference post to Max6 forum in order to excite search engines a bit http://cycling74.com/forums/topic.php?id=40633&replies=12#post-197452 )
  11. Hi there, If I use quaternion to rotate an object in my 3d space, I won't have any gimbal lock right? I know about the efficiency around calculation (multiplications only and no trigo, less memory for storage etc) but wanted to be sure about the lock. Especially, I'm calculating azimuth and elevation using the coordinates X & Z of the resulting vector of translation+rotation to camera space. The atan2 have singularities and I wanted to know if I used quaternion I would "override" these singularities. My maths seem rusty.. Any help would be appreciate
  12. Julien Bayle

    Quaternion rotation VS Euler angles based rotation

    Hi Radikalizm, I understood it like that too. It is the way to avoid it.. I read this : http://www.gamedev.net/page/resources/_/technical/math-and-physics/quaternion-powers-r1095 In the Demo Avoiding Gimbal Lock section, I read this: [color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif]he main point you should take note (in the while loop) is [/font] The orientation of the camera is a quaternion. There are 3 angles corresponding to the keypress. Note the angles are meant to be an on/off switch (not accumulative). I reset them inside the while loop. Of course this is not the best way to do it but as I said, it is a quick job. I convert the 3 angles to a temporary quaternion. I multiply the temporary quaternion to the camera quaternion to obtain the combined orientation. Note the order of multiplication. The camera rotation is then converted to the Axis Angle representation for transforming the final matrix. [color=#282828][font=helvetica, arial, verdana, tahoma, sans-serif]When a key is pressed, I generate a temporary quaternion corresponding to the key for a small rotation in that particular axis. I then multiply the temporary quaternion into the camera quaternion. This concatenation of rotations in 4D space will avoid gimbal lock. Try it and see for yourself. [/font][/quote] In my system (based on OpenGL in Max6 framework), I'm grabbing the cam quaternion and this is that one I convert to matrix and I apply it to all my objects coordinates. This is that resulting vector I'm taking for my atan2 based azimuth calculation. I don't use the temporary vector at all. Maybe my problem comes from here. I don't use it because my system provides me directly the quaternion from the cam. still stuck ?!
  13. Hi there, I'd like to understand how this light diffusion effect is done Each light seems to influence the "space" It seems there is a kind of diffusion. I firstly thought about a kind of open-cubes based grid with transparent faces but which would reflect or distort those lights or whatever. Not sure. Thought about fog too. Would someone have some leads to dig this ? Any kind of leads would be appreciate.
  14. Julien Bayle

    What is this kind of matter ... fog ?

    Maybe I made a mistake by posting it here instead of openGL category :-/ I don't want to double post btw..
  15. Julien Bayle

    Making glowing objects

    dpadam450, I especially posted about the influence of those lights in a new specific thread there: http://www.gamedev.net/topic/626795-what-is-this-kind-of-matter-fog If you'd have any leads, I'd be happy to dig them
  16. Hi there, I'd need tips to make glowing objects. I really liked those visible around 0:25 s in http://www.youtube.com/watch?feature=player_embedded&v=o5z1wEj3tHk I like their glowingness but also the influence they have over the space. Maybe there is fog ? volumic matter ? (sorry for my newbie terms) ANY tips would be really appreciate. fyi, I'm developing in Max6/Jitter, but it is plainly openGL so, any stuff can be transposed to that, no prob. best,
  17. Hi jefferytitan. Many thanks for your answer which is very complete. About culling. Because of calculations constraints in my actual way, I'm already making azimuth/elevation/distance calculations for each object. Can I use these values for culling ? I mean, the usual/classic culling works with the 6 planes intersection detection and a list of object to activate/inactivate. Implementing that in my system would be a cost more, knowing I alread have all A/E/D for all objects. What do you think about the fact I can inactivate/activate about A/E/D ? It would also provide something precious, not all objects would be culled on the same way as you suggest... glowing lighten object could be cull only considering distance, and the others considering distance and position relative to cam. I have to know how to glow like in this video: http://www.youtube.com/watch?feature=player_embedded&v=o5z1wEj3tHk it seems there is like a "matter in the space" (sorry for my newbie words) this would forbid me to cull objects even if they are behind the cam, if I want to have that kind of glowing no? About LOD. I read http://blog.wolfire.com/2010/10/Imposters about that Thanks a lot to have pointed me there. It is an interesting technique, probably classic but totally new for me. I'll dig that for my system, but my system is really much simpler than complex objects to visualize. Those objects would "only" be primitives like spheres, cubes etc. Btw, I'll try to test it. About PVS. god.. 10h I'm here and you already taught me a lot I got it too. in my case, there wouldn't be a predefined path, which means the cam can go everywhere without predictable path. It means it would be hard to use that BUT ... it gives me another idea related to the first answer I had here by BCullis. I could use a global sphere around the cam (I already have it with my distances calculations) (partial) Conclusion if I can cull considering A/E/D, I guess i would already optimize A LOT ! I'll dig LOD for sure.
  18. Julien Bayle

    Little Hello

    Got it. Thanks for your answer and tips Hi there, I'm sure I'll find it VERY helpful. Curiously, I thought it would be only for game developers, but in my huge visual & sound project, I'm flirting closely with this world and it is very interesting. And it gives me ideas for my own CMS because http://designthemedia.com uses it too ( I mean IPS Board) Thanks for your "welcome"
  19. Julien Bayle

    Making glowing objects

    Hi dpadam450, thank for your answer. ok, I got it. glow textures + alpha edges for objects. Apologize about my newbie language in the following part. we can feel like matter in the space, like fog (I'm quite sure it isn't fog) lightens by the light sources (which are objects) the fx is visually pleasant are there some artificial objects not visible but reflecting lights giving the feeling of volumic matter or something like that ? any leads would be appreciate a lot.
  20. Julien Bayle

    Little Hello

    Thanks a lot for your recommendations. I'll do my best for that. Let me know the thread I put in the wrong place, I'll remove it and recreate it in the good one. Ttyl
  21. Hi BCullis, thanks a lot for your answer. Yes I got the strategy you are talking about. This test wouldn't be hardcore in my case, I already maintain a global matrice with all objects' coordinates and I'm calculating their position relatively to cam in order to make some sound processing according to azimuth/elevation/distance (a/e/d) ; so it means I'd add a test about a (big) box around my cam , everything outside AND not in my cam view could be cull ! About the "pure" view-frustum culling part (à la lighthouse3d.com), because I'm already calculating a/e/d for each object, wouldn't be smarter to use this calculation to cull objects and light instead of 6 planes determination, etc etc ? with azimuth & elevation (and obviously, global properties near clip & far clip), I already know which object is in the frustum and outside. right?
  22. this #amazing travel inside #quaternions & #multiplane #matrices is a pure pleasure of #pain #myUniverse #struggle
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