VRAY for SU HDRI lighting

[ntavian]

hello all,
hopefully somebody here can help me on this one.
I am having trouble with VRAY for SU using HDRI files in both the GI (skylight) and the Reflection/refraction (background) slots
I seem to be getting these weird lighting artifacts
anyone have an idea on what is causing them?
switching HDRI files doesn't seem to help

also should the UVW mapping type be set to spherical or spherical (VRAY)

please help

[caecarvalho@hotmail.com]

If you're using V-Ray for SU 2.0 you should use a dome light and load your HDRI on it. Remember to turn of the GI to see only the HDRI lighting (and not the sun light togheter). The way you are doing used to be the old method when there wasn't the dome light. You can find video tutorials of both methods in the Chaos Group site. First you have to login. Then go to services - support - tutorials -v-ray for sketchup.

Caetano

[ntavian]

thanks for the reply, ill give it a try

[simoniii]

Domelight with Sketchup Sun

Hi I am having related issues. I am using a HDRI image on the vray Skydome light, I have turned off everything in the Environment tab, the renders look ok (see screengrabs attached). I was wondering about the use with this settup of the Sketchup Sun? I move it around with the Sketchup Shadows tab, is this the best way to move shadows? Would they be more "correct" if I rotated the Skydome texture? I have been through all the relevant Chaos group etc tutorials, this one https://www.youtube.com/watch?v=IOINU47TWx8 mentions that the vray domelight turns the brightest spot in the sky to a spotlight, and uses that as the sun, but then to move the sketchup sun independently of the sky wouldn't be the best thing to do? Also how do i turn off the sketchup sun, i have tried ticking and un ticking within SKP the "use sun for shading", no effect..
The attached image is ok, but is there any way to make the sun seem brighter? ie more sun on the sunlit facade..it all looks like weak hazy sunshine...I have messed with the domelight texture gamma and intensity...but the sky just gets bleached and the shadows lighten too much. Would be great if vray had 4 standard HDRI Domelights with corresponding standard settings.

[simoniii]

Hi, sorry to muddy the waters with another question but it is related. I saved the file (in last post) with the nice render settings, when I opend it again and renderd I got the very dark result attached.....any simple solutions? I have checked the environment tab, and domelight settings, they are all the same as before...

[tedvitale]

Hi Simoniii,

Can I ask, where are you getting your HDRI skis from? Not all HDRI's are created equally. If the exposure bracketing on them doesn't have enough range you end up with a very soft shadow. It looks like you had your sky light turned on initially, and then it was turned off along the way? Would you be willing to share the scene? I'd be happy to take a look at it and give you a specific answer as to whats going on in the scene. To share a model go to Extensions> V-Ray> Pack scene and send it via a link from your preferred file sharing service if its too large to post here.

[simoniii]

Thanks for that Ted, yes you are right the Skylight was turned on accidentally, I have some other issues with the domelight, I will upload the simplified scene shortly. I would be grateful if you could take a quick look at it. Also I have sourced a better HDRI image.

[peerman]

For stronger shadows you can lower the gamma in the bitmap slot of your hdri texture. Try setting it to 0.8 and render. You probably need to lower the burn value in the Reinhard settings (or one of the other options).
I usually use the RT Vray to quickly see the effect of the sun (and direction of it). I make a simple plane with a cube so it renders quicker. When I'm satisfied I delete or hide these objects before final render.
If you want to use the bright spots of the hdri as a sun make sure you have a big enough image (10,000px wide or more).
Hope this helps a bit!

Regards,

[simoniii]

Thanks Ted and Peerman..I am still getting problem with a large, bought (From VIZPARK) HDRI skydome. Image just looks cold and aneamic (see attached). Any comments/suggestions would be appreciated you can download scene at https://www.dropbox.com/s/l7xujp6dd8...house.zip?dl=0 I have adjsted the gamma on the image rotated the skydome texture, changed the light colour , no improvement, just looks cold. I have asked the supplier as well, but his comments may or may not resolve the issue.

[peerman]

Hi thanks for the scene. I also get the blueish tone. But I think that also has to do with the hdri. I usually use a hdri that is in the afternoon where the sun is set a little lower. The light is more yellow then. You can maybe try Skydome 11 from vizpark which seems to have a lower sun. Also there is Photoshop where you can change the tone of your image to your likings!
Hope this helps a bit?

Regards,

[simoniii]

Thanks for that peerman, have downloaded and used the Skydome 11 hdri with default settings, see attached, its still quite blue, also attached how I have adjusted in in photoshop, ok its a bit better. Ideally I would like a sky HDRI that doesn't render blue, ideally like the "warm_sun" image attached. Can you recommend where I could get such an HDRI from, high quality, please? Thanks for your help.