how to create a laser beam

Hi guys,
i want to create something like laser beam, whose spot size is decreasing the more distant the hit object is. my aim is to create something like a distance measuring simulation. Depending on the beam spot size the distance to an object should be calculated. can me help someone to get a with distance decreasing laser beam spot.

thanks in advance

You can measure the distance with c_trace and create a beam with a particle that got its BEAM flag set. You then need done additional particle at the end of the beam and increase its size with growing distance.

is there any piece of code that throws a spot (like a spot of a laser) on hit surface?. this spot radius should decrease with the increasing distance of the hit area. like a spot of a torch, that is big if it hits a close wall and gets smaller if the wall is more distant. somehow i dont know how to start.

any help will be approciated
thanks in advance

It will automatically get smaller because of perspective, but you can do it manually, too (however, this would be unrealistic).
Uhrwerk already told you how to achieve it, check the manual for c_trace(), vec_rotate(), hit.x/ "target" and effect() or ent_decal().

thanks for replies guys.
finaly i managed to plot a white circle (png sprite) on the c_trace hitted place. the thing now is, that this circle is alleays round. i want to stretch it in one axis according to the angle the beam hits the wall (to make it look more realistic). so now i have to get the angle with which the c_race is hitting the wall.
can someone give me an idea how to get this angle.

thanks in advance

Use the normal vector

so the normalvector seems to be a step in the right direction, but i still dont get the right angle with which the c_trace hits the wall. the code below delivers only angles in 90° steps (90,180 and 270) and not the real angle.

var winkel=my.pan;
vec_to_angle(winkel, normal);

any ideas how to solve it?

thanks for any help

You will need to use a (sprite) entity or ent_decal (where the latter is probably the better choice), particles do not support angles.

You cannot use a fixed skalar where an angle is expected. The functions signature is vec_to_angle(ANGLE* ang, VECTOR* dir).

lol, Change the vel_x, y, z...