Gobo lights


  • Poser Ambassadors

    Any suggestions how to create in Cycles /Superfly gobo lights? I can not get my Gobo lights working. Looks like there is a very different workaround like in Firefly.
    Thanks in Advance for any help.



  • Nope. They sort of work, but not. Anything attached as an image to the light gets averaged. I was just using the brick texture set to black and white, but all it did was reduce the intensity of the spot light. I tried it as a real world example as well, attached the brick texture as a trans mask on a square and got the same thing. The light scatter around the edges of the transparency is too great. I needed to have the mask just above the ground to get any sort of defined edges. I suspect that we may need something like a fresnel lens for our spot lights to make this work. I haven't checked, but I think theatre lights that have gobo attachments all use fresnel lenses to focus the light.


  • Poser Ambassadors

    Thank you . Very sad. I like the effect from Gobo lights. But could not find any workaround in Blender also.



  • I might have found something to get you started... material room set up for a spot light:

    alt text

    then to sharpen the image, change the scale of the light itself to 1%...

    alt text

    You'll then need to adjust the position of the image using the location value in the mapping node. This also distorts the image, so not ideal, but may lead to something better. I don't use gobos, but the option of projecting an image (like a slide projector) would be useful knowledge...

    P


  • Poser Ambassadors

    Thank a lot. Will try this out . Looks like a good basis to start :)



  • I should thank you, Ladonna, 'cus you got me to answer a question I hadn't thought to ask myself yet. It sort of answers your initial question about gobos (but still not quite) but it DID show me how to do projected light (movie/slide projectors). I remembered the old days (when I owned a slide projector) and that when there was no slide in position the illuminated area was quite large. That suggested to me that the lens distortion was reduced by only projecting a small section near the centre, about 10% of the total area. I took an image into photoshop, set up a black square and positioned the image in the middle, occupying about 20% of the total space, then attached it to the set up shown above. With a bit of fiddling to get the image into position and a light scale set to 2% (slightly fuzzy) I got this:

    alt text

    Still not perfect, but a definite proof of concept!


  • Poser Ambassadors

    Gobo lights are in many ways usefull. Not only for indoor Blinds . I use them in the past a lot. Gives the images in many times the last wow,



  • Awesome thread! Thanks all. Here's a screen grab of what was gleamed from the video at this link:

    alt text


  • Poser Ambassadors

    Maybe some of you don't know this site. One of the best when it comes to Cycles lights.
    It is for Blender, but it is valid for all renderengines.

    http://www.creativeshrimp.com/lighting-tutorials-my-way-to-write-a-book.html


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