does anyone know a way to exclude objects/gemheads from lighting?
i tried [emission],[ambient],[specular] and [shinyness] but cant get rid of the shading.

i need to mask a picture with anotherone. so i need to override the mask color with background color. this works, until i turn on the light. then the shading alters the brightness according to the positions of lights and camera.

anybody know how?

Um. Have you thought to put in an off-screen object to block light from striking the objects you want unlit? A barn-door sort of thing.

Ssssssssss

i dont think this is possible, as gem deosnt calculate shadows

You can use low-level/raw OpenGL in Gem with [GEMgl...], so read the OpenGL documentation - it's possible to use glEnable(GL_LIGHTING) and glDisable(GL_LIGHTING), this patch translates that into Pd, I can't attach files for some reason (bug in forum software?), so copy and paste this into a text file and save with a .pd extension:

#N canvas 0 0 396 552 10;
#X obj 8 96 gemwin;
#X msg 28 36 create \, lighting 1 \, 1;
#X msg 30 62 0 \, destroy;
#X obj 95 121 gemhead;
#X obj 95 152 t a a a;
#X obj 206 212 world_light;
#X msg 269 183 1 1 0;
#X obj 269 163 loadbang;
#X obj 205 242 translateXYZ 2 0 0;
#X obj 205 267 colorRGB 0 1 1;
#X obj 27 444 colorRGB 1 0 1;
#X obj 27 269 spigot;
#X obj 176 132 tgl 15 0 empty empty empty 17 7 0 10 -4034 -1 -1 0 1
;
#X obj 150 242 == 1;
#X obj 94 276 spigot;
#X obj 61 246 == 0;
#X obj 133 378 GEMglDisable;
#X obj 202 355 GLdefine GL_LIGHTING;
#X obj 202 332 loadbang;
#X obj 27 468 sphere 1 20;
#X obj 205 291 sphere 1 20;
#X obj 27 419 translateXYZ -4 0 0;
#X obj 94 302 t a a a;
#X obj 94 358 GEMglEnable;
#X obj 67 324 cnv 15 20 80 empty empty empty 20 12 0 14 -4034 -66577
0;
#X obj 332 324 cnv 15 20 80 empty empty empty 20 12 0 14 -4034 -66577
0;
#X text 150 464 [GEMgl*] access low level OpenGL \; OpenGL has glEnable()/glDisable()
\; GL_LIGHTING can be passed in \; [GLdefine] accesses constants by
name \; read the OpenGL Red Book etc;
#X text 72 9 Per-object lighting control in Gem for Pd;
#X obj 181 328 bng 15 250 50 0 empty empty empty 17 7 0 10 -262144
-1 -1;
#X connect 1 0 0 0;
#X connect 2 0 0 0;
#X connect 3 0 4 0;
#X connect 4 0 14 0;
#X connect 4 0 11 0;
#X connect 4 1 8 0;
#X connect 4 2 5 0;
#X connect 6 0 5 1;
#X connect 7 0 6 0;
#X connect 8 0 9 0;
#X connect 9 0 20 0;
#X connect 10 0 19 0;
#X connect 11 0 21 0;
#X connect 12 0 13 0;
#X connect 12 0 15 0;
#X connect 13 0 14 1;
#X connect 14 0 22 0;
#X connect 15 0 11 1;
#X connect 17 0 16 1;
#X connect 17 0 23 1;
#X connect 18 0 17 0;
#X connect 21 0 10 0;
#X connect 22 0 23 0;
#X connect 22 1 21 0;
#X connect 22 2 16 0;
#X connect 28 0 17 0;

thanks a lot!!