HDRI Problems

[Terry Reeves]

I have been running 3ds Max for several years now but have just started using V-Ray about 6 months ago. I really do like it, but am having tons of problems with getting HDRI's to work for me. Maybe I am trying to do something with them that they were never intended for. My understanding is that they are mainly used for lighting and reflections...and maybe a back plate? Anyway, I have an industrial building with a footprint of about 150' x 100' with fairly reflective windows. What I would like to do is have an HDRI in for lighting (and later put in a V-Ray sun for stronger shadows maybe). I want the HDRI to show up in my window reflections, the way they would look in the real world. Problem is, every single time I try this the HDRI shows up in the reflections it seems WAY zoomed in, sometimes so much in fact that the quality suffers horrible. I have tried several differnet HDRI's ranging in quality. I have also tried with and without the use of the V-Ray dome light, with and without using environment overrides, with and without using the Max environment slot. I have watched countless tuts and am at my wits end! No matter what I try I seem to get the same crappy end result. I do NOT want to model an entire environment. I dont know if I have missed something or if what I am trying to accomplish just isnt possible with an HDRI. It seems simple enough, but apparently not. Any insight would be greatly appreciated. If anyone knows of a GOOD tut somewhere that would be great as well. I am using 3ds Max Design 2015 with V-Ray 3.20. Thanks in advance. Another thought I had was to possibly just use the HDRI for the lighting and then put in a V-Ray sun and align and lock it to the HDRI sun. Then cylindrical map a panoramic image to a large cylinder with flipped normals etc. and use that for the actual reflections? I am hoping there is an easier better way than to actually model hills/trees/brush etc. That idea seems a bit on the crazy side.

Edited June 4, 2016 by terryreeves

[Nicolai Bongard]

This depends on the hdri you use. If it was shot with the trees a couple of meters away from the camera, the trees will obviously seem way too zoomed in for your large building. If however the hdri was shot somewhere with trees that were so far away that you could have placed your building on the empty area, it would look like a better fit.

[Terry Reeves]

Thanks for your reply. Your reply does make sense. I desperately need to buy some quality HDRI's. ALL of my HDRI's are freebies that I have found in various places on the web. They range in resolution from about 4k to 10k. I havent really gotten any of them to give me what I want. There seems to a bit of a gray area in what type of HDRI I should actually look into purchasing. I am starting to wonder if I should mainly be looking at sky HDRI's. It seems a lot of people like to use these in combination with a V-Ray sun to acheive the realistic looking lighting/shadows/reflections. If I mainly do architectural work (and currently that is what I do) should I just look at sky HDRi's or how do I determine what type to actually get? Does anyone have any advice? ANy advice on reputable companies that sell good quality HDRI's. I must have a dozen websites bookmarked here that sell them, but I dont know if any of them actually sell quality stuff or not. Most dont give a real good preview of what they are. A couple do have an interactive preview where you can pan it around to see all of it. Thank you in advance for any advice.

[christosviskadourakis]

If you look for HDRI then look no further than Peter Guthrie

[cadmonkey33]

vizpark.com also have a nice selection of hdri skies.

Generally speaking you want to use hdri's without any buildings or trees in them or you'll get weird scaling issues, though this means you'll sometimes need to model some kind of environment around your scene to hide the harsh cutoff of the horizon. Placing a few well positioned trees or a few simple boxes with building textures on them is enough, or grab some low poly buildings from sketchup warehouse. You only need to place them where the horizon is showing in your reflections.

As long as you are using a good quality hdri you shouldn't need to use a vraysun. Make sure you use a vray dome light and place your hdri in that, then you can control the relative strength of the sun vs the sky by lowering the gamma of the hdri (if you need to, which you usually don't).

Edited June 8, 2016 by cadmonkey33

[Nic H]

the CGskies one are my favourites at the moment, high res and great quality. no weird horizons

[Chris MacDonald]

CG Source & HDRI locations