1

Sometimes I get these weird white reflections, that don't look real at all. I have a white sunlamp in the scene. Is there something I can do to stop this?

enter image description here

EDIT:

10x smaller sunlamp, added glare (perfect ad for a washing up liquid).

enter image description here

Noidea
  • 1,256
  • 1
  • 11
  • 31
  • Try changing the emit color of the lamp and see if the reflection changes as well. This would help narrow down the problem at lease. – Josh Silveous Oct 07 '16 at 17:37
  • @JoshSilveous yes, when I change it to green they are green. – Noidea Oct 07 '16 at 17:39
  • 1
    Try Selecting the light object, then navigating to the object panel. Under that, find "Ray visibility". Under that, deselect the "Camera" box. In theory, this should cause the light to render but not the light source itself. I would provide images but I am not currently at my workstation. – Josh Silveous Oct 07 '16 at 17:50
  • @JoshSilveous "Camera" ray visibility had no effect. It disappears when I switched off "Glossy" ray, but of course so do all other glossy reflection of this light, e.g. the one in the middle at the bottom of the picture. – Noidea Oct 07 '16 at 18:00
  • The only thing I can think of currently is moving the light source around until it is out of the reflection, but that does have consequences. Another thing you can do, if you are only trying to render a single frame, is maybe use Photoshop to remove the reflection, or have someone do it for you (I'd be willing to try if you wanted to go at it that way) Also, upload your .BLEND file so we can experiment with it. This website provides an easy and permanent way to upload files: http://blend-exchange.giantcowfilms.com/ – Josh Silveous Oct 07 '16 at 18:11
  • @JoshSilveous thanks for the offer! I have an animation. So this is basically a "normal" behaviour? – Noidea Oct 07 '16 at 18:17
  • Which render engine are you using? – Dontwalk Oct 07 '16 at 18:21
  • @Dontwalk I use cycles – Noidea Oct 07 '16 at 18:23
  • @Noidea You might try using the Light Path Node (in the input drop down) and adjusting "is Reflection Length" with your lamp. Sorry I don't have much experience with this node to guide you further. Generally you want some reflections in glass. If you lit your scene with an HDRi instead you would yield much more realistic/flattering results. – Dontwalk Oct 07 '16 at 18:34
  • @Noidea yes it is normal behavior for the engine, though I think it would look better if the white spots were blurred (feathered) rather than sharp. Try increasing the roughness panel on the material you used for the glass. – Josh Silveous Oct 07 '16 at 18:37
  • @Dontwalk, thanks, I will try to do something with it.. I have many reflections of the glass, but this is the area where the sky reflects. – Noidea Oct 07 '16 at 18:38
  • 1
    @Noidea Here is a link to some free "Garage" like HDRi's that might work really well http://www.mrbluesummers.com/category/downloads/downloads-textures-materials and one of many tutorials out there https://www.youtube.com/watch?v=_4IN4V1SM-A – Dontwalk Oct 07 '16 at 19:51
  • Anytime you have highly reflective surfaces like the ones on a car, think of what is going to be reflected on them. The light sources will be reflected on it no matter what, so make them as big and interesting as possible. As a refference read this: http://www.zacuto.com/how-to-light-a-car –  Oct 07 '16 at 20:30

1 Answers1

4

That is the reflection of the sun lamp. The size is related to the size property of the lamp. If you change it to 0, it will disappear. You will also have perfectly crisp shadows.

The sun lamp reflection looks unnatural because cycles produces a perfect reflection, instead of the soft edged sun were used to seeing because of the atmosphere. And there is no bloom that happens in your eyes or in cameras to bright objects. More info

So instead, You can add the bloom as a post process.

Or, use HDR an illumination map instead of a sun lamp.

Or, on the lamp, uncheck the box for "Multiple Importance". If the glossy shaders have no roughness, or set to "Sharp", the glint with disappear...

More info on multiple importance: 1 2

Community
  • 1
JTxt
  • 183
  • 8
  • Thanks, so as far as I see every solution to these problem has its downsides, e.g. unchecking multiple importance leads to noisy render. I'll try the composer. – Noidea Oct 07 '16 at 19:17
  • 1
    Also, your sun reflection seems very large, You may also consider also reducing the size... perhaps from the default .1 to .01. if not lower... as well as adding a bloom. But again, the point is that cycle's sun does not work like the sun we're used to. I'd look into HDRI. – JTxt Oct 07 '16 at 19:34
  • yes, I had 0.1 sun, reduced it and the highlight is much smaller now. HDR is good, but I find it hard to get the sun in the right direction. And I need to show some different background, because rotated HDR looks weird. – Noidea Oct 07 '16 at 19:48