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Member Since 21 Jun 2012
Offline Last Active Jul 03 2012 01:30 AM

Posts I've Made

In Topic: Light sources lighting volumic matter?

01 July 2012 - 01:38 PM

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)

In Topic: Light sources lighting volumic matter?

29 June 2012 - 02:11 AM

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 ..?

In Topic: View-frustum culling VS azimuth/elevation for objects inactivation/activation

24 June 2012 - 01:24 AM

I understood all the point :)
maybe it means I'm not that a beginnerPosted Image

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 Posted Image

In Topic: Quaternion rotation VS Euler angles based rotation

23 June 2012 - 10:37 AM

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 :P http://cycling74.com/forums/topic.php?id=40633&replies=12#post-197452 )

In Topic: Quaternion rotation VS Euler angles based rotation

23 June 2012 - 06:16 AM

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:

he main point you should take note (in the while loop) is

  • 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.

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.

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 ?!