Weird light on facade (don't think it is sunlight!)

[proseduction]

At this moment i am trying to make a nice render of this flat/appartment building, but i got some weird light spots on the second and fourth level. Is this just because the angle with the sun? or is this because something else? i really would like to have an image from this side so how can i solve this issue?

With the second image it is visible that it is not just the angle of the sun i think! i exploded the whole model so everything must be visible and I only use 4 materials. And i made the glass myself with some refraction and some reflection. So is this maybe the cause? the refraction layer?




An update: I just tried to deactivate the refraction layer of the glass and then i noticed that the glass was see through, but the "light" was gone.

[TqM]

Re: Weird light on facade (don't think it is sunlight!)

screenshot or saved render image please.

[TqM]

Re: Weird light on facade (don't think it is sunlight!)

That is quite strange. It is most definitely a refraction problem, I suggest if using the default refraction settings, and then just playing around with the 'filter' render, and take the other setting step by step. I would say it is an IOR issue but i think it would be a little bit more wide spread if that was the issue.

[aimer32]

Re: Weird light on facade (don't think it is sunlight!)

Right now i am within my exam period so i am not able to play around at this moment! I will try to do so this week. The weird things is when i take a render from another corner the light is on a different place and sometimes more brighter! But i will post my results here! Thanks for the help.

[Jackson_cg]

Re: Weird light on facade (don't think it is sunlight!)

First off, if that glass is a single face then you should either remove the refraction layer or change refraction IoR to 1. You can't use refraction with single faces as they doesn't exist in reality so the refraction calculation (which relies on light entering and exiting a transparent solid) gets screwed up causing all sorts of problems. The same goes for any render engine. If you want realistic refractions you will have to model glass with realistic thickness, i.e. two faces with normals facing outwards.

Secondly, it's hard to make out from that image, but if the Highlight Glossiness of your architectural glass is set to anything but 1, change it back to 1. As Highlight Glossiness is a "cheat" (it simulates highlights as though there were spotlights in the scene even if there aren't any) it can cause bright spots when viewed from certain angles. I almost never tough the Highlight Glossiness parameter for arch work, only for product/studio stuff, besides, regular non-frosted arch glass should have a glossiness of 1 in any case.

If that's not the cause then I'm stumped.