I am starting to believe...

[Quick Karl]

... that 3D rendering software companies are all run by George Soros because all any of these programs do is make the company owner, richer.

What is wrong with my ceiling????



SU Pro 2017 Vray 3 (no comments on the interior design please this is just a test render - I downloaded Vray this afternoon (26 April 2017)).

Any ideas to get me pointed in the right direction will be much appreciated.

I've viewed and read all of the Chaosgroup tutorials -- even the tutorials in bad-English -- no luck; I am having the same annoying ceiling result even when I follow every step in VRAY's tutorials. Global Illumination is NOT WORKING.

One would think that by 2017, someone could come up with a rendering add-on that makes rendering an interior, easy.

I'm not trying to do a 3D Art school project that has to look like a photo - it just has to be a reasonably clean illustration and spending days reading Chaosgroup tutorials/instructions from 2012, is beyond frustrating, and I shouldn't have to write and essay on every spec of my system or every setting in VRAY, just to create a simple lighted interior illustration that doesn't look like an 11-year old did it.

OK

So, Started from scratch - created box, cut a hole in the side, added a portal light - changed the intensity from 30, to 5000 to 0, no effect on the interior, whatsoever. And before anyone gets all Einstein-ish - YES the light is enabled.

SO there must be a secret switch somewhere, burried in a place that s NOT obvious, that will get the portal light to actually do something?

Next, for fun, I added a VRAY infinite plane - applied VRAY grass to the infinite plane -- the infinite plane is unusually rectangular (like 1:4) and the grass is stretched and looks obviously wrong through the hole in the box in the render.

If you view the infinite plane in SketchUp, the material looks like it is supposed to.

Must be my computer, huh...

Win7 Pro SU2017, VRAY 3, i7 980, 24G memory, and Nvidia GTX 980...

[andybot_cg]

Try getting some exterior light in from the windows, that may bring up the light levels and help your dark ceiling. You could just ask for pointers instead of getting into a political rant

[Quick Karl]

I tried portal lights - as I said, I followed every step in the tutorials.

If you are referring to some specific setting for getting more exterior light into the room, I am all ears.

[andybot_cg]

It's hard to say without the file. It could be that your glass material is incorrect and not letting in light. It could be that you exterior lighting is not strong enough. You could strip your model of everything but the walls, windows, and lighting and post it here.

[Quick Karl]

Thank you, Andy.

I've figured out the ceiling by adding a huge rectangular plane light 1/2" to the interior of the ceiling, and adjusted the intensity till I liked it.



Now to try and figure out why the exterior light no longer shines through the windows from the exterior when I switch from interactive/progressive rendering to CPU rendering...

[andybot_cg]

Try putting the glass in the windows on a hidden layer, I suspect there may be some issue with your glass material. There are differences in how materials are handled between CPU and GPU.

[Quick Karl]

Good thinkin' !



I wonder what could be wrong with my glass? It is, in fact, VRAY glass.

Also, another interesting phenomena; if I switch to progressive GPU rendering, the plane light that I added to the ceiling, does not work.

[Quick Karl]

Thanks for all your help Andy!

I used VRAY window glass this time, but now I can't drop a background behind the windows in a .PNG?

[andybot_cg]

Great! Glad to see you're making progress. I'm not sure why your windows aren't transparent in the PNG. Which material setup did you end up using? There are still some kinks in this new release of Vray for Sketchup, and there seem to be some issues with material transparencies. Hard to say what's exactly the reason without more details.

[Peter.Chaushev]

Hello, Karl,
To make the glass actually transparent in the rendered Alpha channel, simply select the glass material, open its advanced settings (the right-side panel) and at the bottom of the settings adjust Options > Color > Alpha Contribution to 0.

Kind regards,
Peter Chaushev

[Brett]

Check your portal lights are aimed correctly: I had one set with the *back-face* showing through the window and of course no light came from it. Duh moment when I realized it was trying to light the rest of the universe.

[luisov]

Peter, your suggestion helped me in figuring out how to make a glass material be transparent in the Alpha channel which I've been struggling to figure out for a while. So thank you. However I have other elements behind the glass that disappear in the view altogether since in the Alpha channel the glass is completely black. In the older version of VRay this wasn't an issue and I could still get the transparency but also see the objects behind it. What do you suggest I can do to allow for elements behind the glass with Alpha Contribution set to 0 to still be visible? The ultimate goal for this is to add a scene and sky in post-production. Thank you.

[Peter.Chaushev]

Hello again,
In this case disregard my previous comment, set Alpha contribution back to 1. Then in the Glass material's Refraction section simply set the "Affect channels" to "Color + Alpha".
This will give the glass partial transparency in the alpha channel, based on the refraction value.

Kind regards,
Peter