<div dir="ltr">Light Falloff node attenuates light energy according to the ray length. What you need instead in order to have laser effect is to attenuate light energy to zero if projection of shading point onto the light source falls outside of the emitting geometry.</div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Sep 2, 2015 at 1:26 PM, Mohamed Sakr <span dir="ltr"><<a href="mailto:3dsakr@gmail.com" target="_blank">3dsakr@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">well I guess the best is: the light got a node already "Light Falloff node" , which can represent strength by a texture for objects, here you can also add 1 more input for the cone angle "and it should be used within sampling, instead of the full hemisphere sampling, I expect you would use the spot light cone sampling function here" , this will be totally dynamic with all infinite capabilities.<br><br></div><div class="HOEnZb"><div class="h5"><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Sep 2, 2015 at 10:18 AM, Sergey Sharybin <span dir="ltr"><<a href="mailto:sergey.vfx@gmail.com" target="_blank">sergey.vfx@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">I'm not sure what exactly spread angle means in this context, you already have it for spot lights and adding spread angle to spot and sun lights is somewhat malformed.<div><br></div><div>What we can do instead is either of:</div><div><br></div><div>- Modify energy function of area light, so it only contributes light inside of a beam defined by it's area. Should be quite quick hack, but would require some tweaks to PDF to make MIS working correct. Also circular lasers can not be supported by this. This seems exactly what Lux does (maybe internally they actually switching from rectangle to circle tho).</div><div>- Make spot light's source non-zero. Effectively making it to shoot cylinder instead of a cone. </div><div><br></div><div>We can also go totally crazy ans support Laser option for any object, so even meshes with emission shader can be acting as lasers, making it possible to use laser beam of arbitrary shape.</div></div><div class="gmail_extra"><div><div><br><div class="gmail_quote">On Wed, Sep 2, 2015 at 12:56 PM, Mohamed Sakr <span dir="ltr"><<a href="mailto:3dsakr@gmail.com" target="_blank">3dsakr@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hey Sergey,<br><br>I guess we can add a spread angle parameter to lights? "hemisphere cone"</div><div><div><div class="gmail_extra"><br><div class="gmail_quote">On Tue, Sep 1, 2015 at 5:03 PM, Constantin Rahn <span dir="ltr"><<a href="mailto:conz@vrchannel.de" target="_blank">conz@vrchannel.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br>
It's not possible with cycles, but it's available in Luxrender 1.4+ and<br>
an area light with "laser on".<br>
<a href="http://www.luxrender.net/forum/viewtopic.php?f=16&t=11572" rel="noreferrer" target="_blank">http://www.luxrender.net/forum/viewtopic.php?f=16&t=11572</a><br>
<br>
<a href="http://www.luxrender.net/forum/viewtopic.php?f=12&t=11533" rel="noreferrer" target="_blank">http://www.luxrender.net/forum/viewtopic.php?f=12&t=11533</a><br>
"- add constantinfinite, laser lights"<br>
<br>
Sorry for pointing to other FOS software in the cycles ML. ;)<br>
<span><br>
<br>
Am 01.09.2015 um 16:51 schrieb Zauber Paracelsus:<br>
> The problem with that, however, is that the laser would be visible when<br>
> it is not passing through the mist as well.<br>
><br>
><br>
><br>
> On 09/01/2015 10:48 AM, Mohamed Sakr wrote:<br>
>> actually this is not possible with lights, your only solution is a<br>
>> cylinder object "acting as your laser light" , and put an emission<br>
>> node in the volume output "leave surface empty"<br>
>><br>
>> On Tue, Sep 1, 2015 at 4:42 PM, Zauber Paracelsus <<a href="mailto:zauber@gridmail.org" target="_blank">zauber@gridmail.org</a><br>
</span><span>>> <mailto:<a href="mailto:zauber@gridmail.org" target="_blank">zauber@gridmail.org</a>>> wrote:<br>
>><br>
>> Would it be possible to change the minimum angle width of a spotlight<br>
>> from one degree to zero? I was tinkering with a scene filled with<br>
>> mist,<br>
>> and wanted to create the effect of laser lights transmitting through<br>
>> mist, which would scatter their light and make the beam visible. The<br>
>> closest light I could think of that would produce the effect was a<br>
>> spotlight, but due to its minimum angle width of 1 degree, I am<br>
>> not sure<br>
>> if I can accomplish the effect.<br>
>> _______________________________________________<br>
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>><br>
>><br>
>><br>
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<br></blockquote></div><br><br clear="all"><div><br></div></div></div><span><font color="#888888">-- <br><div><div><span style="color:rgb(102,102,102)">With best regards, Sergey Sharybin</span></div></div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature"><div><span style="color:rgb(102,102,102)">With best regards, Sergey Sharybin</span></div></div>
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