glLight/spot light

[Nicky Peter Hollyoake]

without making the squares smaller and making more is there any way, or what would be the best way to make the light smoother? I'm hoping it's possible, or I have to modify most of my game to deal with this.

'// spot light test //
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)
glEnable(GL_DEPTH_TEST)
glShadeModel(GL_SMOOTH)
glLightfv(GL_LIGHT0, GL_DIFFUSE, Vec4(1, 1, 1, 1))
glLightfv(GL_LIGHT0, GL_AMBIENT, Vec4(0.1, 0.1, 0.1, 1))
glLightfv(GL_LIGHT0, GL_SPECULAR, Vec4(0.9, 0.9, 0.9, 1))
glLightfv(GL_LIGHT0, GL_POSITION, Vec4(0, 0, 5, 1))
glLightf(GL_LIGHT0, GL_SPOT_EXPONENT, 2)
glMaterialfv(GL_FRONT, GL_DIFFUSE, vec4(1, 1, 1, 1))
glMaterialfv(GL_FRONT, GL_AMBIENT, vec4(1, 0, 0, 1))

dim x, y
dim mx#, my#, s#=5

while true
   glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT)
   
   mx# = mouse_x() * 2
   my# =-mouse_y() * 2
   s# = s# + mouse_wheel()
   
   glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, vec3(-1+mx#, 1+my#, -1))
   glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, s#)

   for y = 0 to 19
       for x = 0 to 19
           glPushMatrix()
               glTranslatef(x-10, y-10, -30)
               glBegin(GL_QUADS)
                   glVertex2f(-1,-1)
                   glVertex2f(-1, 1)
                   glVertex2f( 1, 1)
                   glVertex2f( 1,-1)
               glEnd()
           glPopMatrix()
       next
   next            
   
   swapbuffers()
wend

- Nicky

[matthew]

Don't you have to use glNormals when you want to light something correctly, or aren't they relevant here?

[Nicky Peter Hollyoake]

No, glNormal isn't relevant here. My problem is the lighting is being effected per face, can you change it to per vertex/pixel? If not I have to make 10s/100s of little squares to pull off a nice effect. I heard of something called OpenGL projected texture? Anyone know anything that can direct me with more information about that? Done some searches but nothing that helps much. It's for a torch I'm making in 2D (Birds view).

- Nicky

EDIT: Here's closer to what I want but you can still see the faces...

'// spot light test //
glEnable(GL_LIGHTING)
glEnable(GL_LIGHT0)
glEnable(GL_DEPTH_TEST)
glShadeModel(GL_SMOOTH)
glLightfv(GL_LIGHT0, GL_DIFFUSE, Vec4(1, 1, 1, 1))
glLightfv(GL_LIGHT0, GL_AMBIENT, Vec4(0.1, 0.1, 0.1, 1))
glLightfv(GL_LIGHT0, GL_SPECULAR, Vec4(0.9, 0.9, 0.9, 1))
glLightfv(GL_LIGHT0, GL_POSITION, Vec4(0, 0, 5, 1))
glLightf(GL_LIGHT0, GL_SPOT_EXPONENT, 100)
glMaterialfv(GL_FRONT, GL_DIFFUSE, vec4(1, 1, 1, 1))
glMaterialfv(GL_FRONT, GL_AMBIENT, vec4(1, 0, 0, 1))

dim x, y
dim mx#, my#, s#=15

while true
   glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT)
   
   mx# = mouse_x() * 2
   my# =-mouse_y() * 2
   s# = s# + mouse_wheel()
   
   glLightfv(GL_LIGHT0, GL_SPOT_DIRECTION, vec3(-1+mx#, 1+my#, -1))
   glLightf(GL_LIGHT0, GL_SPOT_CUTOFF, s#)
   
   for y = 0 to 19
       for x = 0 to 19
           glPushMatrix()
               glTranslatef(x-10, y-10, -30)
               glBegin(GL_QUADS)
                   glVertex2f(-1,-1)
                   glVertex2f(-1, 1)
                   glVertex2f( 1, 1)
                   glVertex2f( 1,-1)
               glEnd()
           glPopMatrix()
       next
   next
   
   swapbuffers()
wend

[matthew]

There's an example of using torch-light in a 2d game here. However the designer has created a texture and just blended it to achieve the lighting effect, rather than use OpenGL lighting.

As for lighting per vertex. Well you've already discovered that if you divide the quad into smaller quads you're just creating more vertexes which is why the lighting looks better. :-)

[DJLinux]

Normaly per pixel light neet a OpenGL shader
or you can try this basic4gl.proboards.com/thread/3412/light-lights

DJ.