topic Re: Resolution HDRI in 3ds Max Shading, Lighting and Rendering Forum

Resolution HDRI

Darwin33 — Fri, 10 Aug 2018 06:52:44 GMT

Which resolution do you use in your HDRI images to lighting an scene. What is depending on?

Re: Resolution HDRI

darawork — Fri, 10 Aug 2018 11:10:30 GMT

We use HDRI images at 24000px X 12000px in 32bit format HDR file format.

The important part is the bit depth, 32bit. As this contains the broad spectrum of colours needed for illumination.

The aspect ratio should be 360°x 180° e.g. an equirectangular image. Twice as wide as it is high.

It's no use using anything lower than 32bit, and the file format needs to be HDR or EXR.

JPG, TGA, TIFF, ETC.. are unsuitable for illumination needs.

https://www.ronenbekerman.com/hdr-image-based-lighting-3d-scene-setup/

https://www.ronenbekerman.com/10-free-hdri-spherical-skies-maps/

Regards,

Re: Resolution HDRI

Darwin33 — Thu, 23 Aug 2018 06:47:38 GMT

I have two more questions about HDRI illumination.

1° There is many images HDRI in the web I guess that you must select them in accordance with the landscape and time hour of the day of the scene you want to illuminate. IE, noon in an forest, night in a beach. Can anyone confirm this?

2°If I only want my HDRI image only for lighting purposes ( I mean I don't want the background image on my picture) should I disable the environment tab, or if I disable that tab I won't have all the lighting features of the HDRI image in my scene?

Regards

Re: Resolution HDRI

Anonymous — Thu, 23 Aug 2018 09:40:52 GMT

If you only want the HDRI for lighting you don't need a huge resolution (above 5k) , it won't make any difference and will use plenty of resources.

Keep in mind many HDRI resources in internet are not properly set for accurate HDRI. For example in most of them the sun is too weak etc. Also it depends for what you want the HDRI. Some people prefer a weak sun as they can use the HDRI as ambient and place a manual sun for better control. You can check in photoshop the different exposures of light with the color picker.

You obviously need to choose the "mood" of HDRI that fits betters your needs.

About settings, you are not mentioning the renderer you are using and the setting method you are using.

Re: Resolution HDRI

Darwin33 — Fri, 24 Aug 2018 14:02:12 GMT

I am using Vray and settings by default. Only lighting with HDRI , no sun light object. Does the tab environment any influence in the lighting of the scene or is only for applying the image like background?

And if I want to use a sun like object, wich kind of light do you suggest, dome, sphere ? and distance and intensity to the scene should I set?