I'm coming from photography. So: I made a champaign bottle in 2.78 with a fine shader, now I need those light's reflections in the glass to become nice and soft.

I set up 2 "strip lights" (emitting planes) to bring out the shape, but the reflection is rather harsh and unpleasant.

In photography, I'd place a strong diffusor right in front of the lights to avoid those razor sharp reflections. But how can I achieve that in Cycles?

Of course, I would not alter the glass material. So either there is a way to modify the light source, light path or the light itself.

Should I bounce the light off of a less reflective material onto the bottle? Like a reflector in photography. Or should I place some kind of material in between lights and subject?

I've found a blur node, but I haven't used the compositor yet enough to know my way around. There is also supposed to be an "Integrator" according to the online documentation, but I have failed to find it in the software.

Please help, dear Blenderers 😊

  • 3
    $\begingroup$ Could you add some pictures? What you have got by now and what you want. $\endgroup$
    – cgslav
    Jan 23 '17 at 11:32
  • $\begingroup$ goo.gl/images/CpHIqm I've got the right side, but I'm striving more like something in between of both. The reflections need to look blurry, soft. $\endgroup$ Jan 23 '17 at 12:47



You can make your light source (Plane with Emission) 'diffused' as you want.

I've created this:


Then applied it as a Mix Factor between Emission and Transparent shader:


With this method you can create any light diffusion you want.

  • $\begingroup$ Wow. That looks pretty much like what I'm going for. So it's, basically, a cheat? But a good one! $\endgroup$ Jan 23 '17 at 14:59
  • $\begingroup$ I don't think it's a cheat. Not in a way as Gleb Alexandrov is cheating lightning in Blender (this is amazing btw). You just create your own lamp as you like. You can use for this Addon Images as Plane to speed this process up. And don't forget to set Transparent Shader to pure white. I'm photographer too so I dig lighting in Blender a lot ;) $\endgroup$
    – cgslav
    Jan 23 '17 at 15:03
  • $\begingroup$ Just so I know I'm getting this, sorry, bit old, bit slow: I apply this as a texture to my lighting plane? I can follow the nodes, yes 😀 $\endgroup$ Jan 23 '17 at 15:07
  • $\begingroup$ Super cool! Sorry, just read your last comment ☺ $\endgroup$ Jan 23 '17 at 15:08
  • $\begingroup$ It's not texture as is. It's just mix factor. And Non-Color Data in Image Texture Node is important as well. If you like the result, don't forget to upvote/accept my answer ;) $\endgroup$
    – cgslav
    Jan 23 '17 at 15:09

There is no real diffusion ability currently modeled in Cycles. I discussed this with Brecht years ago, but interest seemed low. One could potentially add an SSS plane to simulate it.

The only method to achieve soft and diffuse sources is to modify the size component of certain lights. If you come from a photographic background, I would suggest you might find area lights or mesh lights set to emission shaders as a tool of choice, as you have tried.

A key component of diffusion sources is that they typically end up closer than the lamp in question, increasing their size. If you found your area / mesh lamps too specular, try increasing their dimensions significantly.

On the upside, in addition to the lamps themselves, you can place gobos and cutters in your frame to control the spill, and simply turn their visibility to camera off.

  • $\begingroup$ Thank you, that seems like a plan(e) ☺ I have light emitting meshes atm, but I'll try area lights instead, but first the SSS plane. Any pointers to a tutorial or suggested settings? I'm still struggling a bit with cycles, the glass alone took 5 attempts at "realistic glass" of which only one was halfway realistic, so I'm just trying to save man hours here 😀 $\endgroup$ Jan 23 '17 at 13:07
  • $\begingroup$ I would start by suggesting you adjust the view transform to be more akin to what we expect on a photographic response, then see if you require further diffusion on sources. Much of the "harshness" is due to the view transform. blender.stackexchange.com/questions/46825/… There are a good numbers of samples out there now, and even the glass shader, with its energy losing formula, can end up looking quite solid. $\endgroup$
    – troy_s
    Jan 23 '17 at 13:10
  • $\begingroup$ All right, I'll try that first then! I'll be back when I managed to apply your solutions. Thanks a bunch ☺ $\endgroup$ Jan 23 '17 at 13:16
  • $\begingroup$ The view transform... could you please point me to a resource? I can't make heads or tails out of it. I just find resources on vector transform. I checked the other topic you posted concerning the issue, but it's far too advanced for my current state of sucking at this ^^ At first, I thought my camera was transformed into a to small size, just to give you an idea about the little monkey you're talking to. Most of my half forgotten knowledge stems from pre-2.5... $\endgroup$ Jan 24 '17 at 10:39
  • $\begingroup$ @MarkusSchlögl It might be a stretch for you just getting back into it. There is a small "installation" process. Feel free to ask at chat.stackexchange.com/rooms/34814/the-rabbit-hole $\endgroup$
    – troy_s
    Jan 24 '17 at 13:02

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