View Full Version : I do not want the HDRI reflected in windows!

02-08-2016, 07:08 AM
Is there any way NOT to have the HDRI refelected in my buildings windows when using hdri? Im happy with the lighting set up from it but i want a totally different image reflected in my windows but the HDRI isnt allowing this... The HDRI image im using is a beach scene and the model im building is 'supposed' to be in a victorian street... So the sea is reflected in the windows!
Is there anyway to set up a seperate image to reflect whilst still using the existing HDRI? Or even a plugin?

02-08-2016, 08:16 AM
Assuming the HDRI is in the background as an ImageWorld or Textured Environment, you could always map the sky you would like as a physical, inverted spherical object, 100% luminosity and 0% diffuse (smoothing on obviously), and have that in your scene as a huge sphere that encompasses the scene. Turn off Self Shadow, Cast Shadow and Receive Shadow for the sphere (I call mine a SkyGlobe), and turn on Unseen by Radiosity in the object's render panel, as well as Unaffected by Fog. As long as Unseen by Rays is left un-ticked, it'll show up in your windows if their reflections are set to Raytrace & Background. If you don't want to see the sky in the renders themselves, just the reflections, then tick Unseen by Camera.

Hope that helps.

02-08-2016, 08:27 AM
What about to change reflection options for your windows glass surface ? In surface editor/environment tab, change Raytracing + Backdrop to Spherical Map then attach there desired reflection image.

02-08-2016, 09:09 AM
Cheers guys!
both worked a treat.. though the spherical map option was a lot less messing around

02-09-2016, 04:43 AM
The method I always used to use was a 10x10 red png (132325 enclosed). I set it as the backdrop image and because it was red I could edit it in Image Editor to reduce sat to make it black or white or change hue to make it any colour I wanted. If you set it as backdrop, it covers up Image World but still allows that to shine through. In 2015, you don't need it because you can set a single backdrop colour.

PS. It doesn't matter that it's so small. It's a single colour and will get sized to your render resolution.

02-09-2016, 01:09 PM
The beauty of the spherical mapped option is you can change your image easily and it will affect everything, without having to change the individual reflective surfaces' properties. So when you next reuse an item in another scene, you don't have a sky reflecting in the glass that looks out of sorts with the rest of the scene, forcing you to alter them all. I've been there and done that, and go for the spherical sky option most times now :)

02-09-2016, 01:16 PM
Two other options I use is to either blur the image or use relflection bur or both. For some things this can give a desirable look.