Image behind window with sun lights

Hi guys,

I’m new to this forum, but I’ve read quite a few posts before deciding to post. I’m using and testing Sketchup 2017 (with vray 3.6). I have one issue and I can’t find any good solution, maybe you can advice.

I’m trying make interior render scene from house and put image behind window/glass (like trees). I’m building small wall and put texture there - but this block sun lights at scene. Is there any way to make this wall/texture transparent for sun lights?

I’ve found few posts with similar question - but there is no answer. Also I’ve tried use hdri dome/spherical photo, but this is not good enough for me. I need put texture close to window.

I’m not interesting to do this in post-production. I have lot of scenes and looking for simple solution.

Thanks in advance,

Is the texture image transparent or opaque ?

First I would highly recommend re exploring quality HDRI environments first as that’s the best solution here, in my opinion.

If you still insist on placing a picture on a wall outside the windows, to fake the outside, just make sure VRAY knows you don’t want it to receive or cast any shadows. This isn’t so much a sketchup thing as it is a vray thing in the end.

Best of luck.

It might help to make the outside face of the window transparent - and if you’ve drawn the window with thickness for a pane, both the outside faces of the window.

Not sure it that lets sunlight through, but I know it lets you ‘look in’ from the outside, while if you leave the inside translucent or opaque, you can see any texture or tint inside.

Origingally found this some years ago in a post about letting you see inside a small model - by making one or more of the outside faces transparent, but when you orbit around the model, they go opaque from the opposite side, when the inside face is what you are looking at, through another wall, say.

There are many solutions for this, but to keep you where you are now, the trick might be to make that wall bigger and move it further away from the window which might allow the sun to get in the window ( assuming it’s not a sunset moment) over the top of the wall…perhaps that could work. You will also need to light the wall or make it emit light so its bright like the sky. However HDRI is a better solution and it can light the scene too. Lots of free ones here

Thanks guys for all this. I’ll try once again with hdri. I think this is best option. I’ve tried already before - but there is always problem with hdri scale. My object - house is small and hdri area is so big, that I need enlarge my house and than all dimensions/scenes etc are wrong. I also tried find scale option in hdri, but as I remember from documentation there is no such thing like scale in hdri.

But I’ll try and maybe make my own hdri area. Other options including wall far away from window is ok - I’m doing this right now - but images from interior looks unnaturally sometimes - thats why I’m looking for better solution.

Please do not misunderstand concepts.
A hdri is thought to illuminate and you are talking about the background.
If you want to place your background directly in Sketchup with an image, without affecting your illumination, as you first asked…you can set the material of the image to not cast shadows in the vray material editor.
In case you imported the image as a picture, you need to explode it to get that as a material.
Of course, there are many other ways to place the background, for example in post production with help of the alpha channel, etc…
Btw. for interior renderings in vray (until the version next), you could use portals in the windows (rectangle light with the portal option enabled) to improve the performance.

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Thank you for information. I’m always using portal inside and rectangle light at outside (turned inside) and wall/image as background.

I’m aware about post-production, but I don’t have time for this. If I’m rendering 10 scenes at one project is easier for me put image behind window than edit each scene at post-production.

Also tried put models behind window (trees/garden/flowers/sky/etc) but this is to heavy, to big and all this is to slow. (My projects are already huge ~500mb each without outside “garden” models).

Thank for all information, all this is very helpful and I’l try use all this soon.