topic Re: Lighting with hdri in 3ds Max Shading, Lighting and Rendering Forum

Lighting with hdri

Darwin33 — Sat, 11 Aug 2018 19:53:14 GMT

I know how to set up an HDRI image to light the scene, but normally the intesity of the light is not accurate, or too low or too bright. I understand that there is two ways to set up the lighting,

1 in the editor material adjusting the overall multiplier or the render multiplier.

2 Also in the material editor adjusting the output amount

3 In the dome light adjusting the intensity.

Which one is the best I should use.

Re: Lighting with hdri

miledrizk — Sat, 11 Aug 2018 20:50:07 GMT

Hi,

You can choose anyone of these settings, i personally use the Dome intensity because it's quicker to

Reach. But one parameter i like to adjust almost all the time is the Inverse Gamma. It's in the VRayHDRI material in

The material editor, Color Space rollout. I like to set it below 1.0, generally around 0.75 or 0.8, you can experiment,

But remember not to decrease it too much because it will give bad results. Lowering this value a little will

Add some contrast to the HDRI texture which in return will enhance the lighting and will give more vibrancy.

Re: Lighting with hdri

Francisco_Penaloza — Mon, 13 Aug 2018 22:51:35 GMT

Well actually, each value will affect the way the image in a different way.

overall the results are 'similar' but depending on the image these would be very different.

I am guessing you are talking about loading an HDRI on V-Ray HDR shader.

In that case, the overall multiplier will make the image more or less bright on your viewport and when rendering, V-Ray give you the option to separate these if you like.

If you go to default 3D Max bitmap controls, the RGB value will increase the colors values, this will make the image 'brighter' by saturating the colors. This can create excessive color bleed or color splotches.

If you use the output value this is the mix between the bitmap and the default material color.

Overal I would recommend using the Light intensity first. This will increase the lighting and project the colors of your HDRI on the scene.

If you move any other value the effects you'll get will depend on the quality of your HDRI and here is where it gets tricky, as mentioned by @miledrizk the common quick fix of low dynamic range images is using the inverse gamma value, this create more contrast in the image, producing more saturated colors and 'shaper' shadows. Having said that, if your HDRI is high quality (not the size but actual amount of lighting information) you don't need to do this inverse gamma fix.

The latest Guthrie or HDRI heaven or Hyperfocal are samples of High quality, well developed HDRI to be used as background and also lighting.

Free ones you'll find online quality will vary.