hello , i have a question about camera in openGL why the vecto r of direction of camera is in reverse ?  what is the reason behind it ?

d8a60p6w.bmp

I have no idea what is rendering those images or what the "Direction" image is supposed to be representing.  But if you mean the solid purple vector, it looks like it's just the camera transform's z basis vector.  So the camera world facing vector would be the negative of that.

Not sure what you're doing either but keep in mind there is a left handed and a right handed coordinate system, so if you are doing say a cross-product, the resulting vector may be the opposite of what you think it should be.  I don't work in OpenGL but I think it's right handed while Direct X is left handed by default. Someone correct me if I'm wrong on this.

51 minutes ago, 0r0d said:

But if you mean the solid purple vector, it looks like it's just the camera transform's z basis vector

thanks i got what you say it solved the problem i had in my mind