Using HDRI in V-Ray for SketchUp

Using HDRI in V-Ray for SketchUp by Nomerdona

HDRI stands for High Dynamic Range Imaging. It is a technique that allows a larger span or range of luminance between the light and dark areas of an image. You can use Photoshop or Photomatix to create HDRI. For this tutorial I will not talk about how to create them but rather how to use them in V-Ray for SketchUp. I love DOSCH HDRI but if you want some free excellent HDRI you can visit my favorite site hdrlabs.com . Please don’t forget to acknowledge them.

Let me begin this tutorial by using this simple SketchUp setup composing of different types of glass urns using the follow me tool. Since I already rendered the scene before writing this tutorial, the V-Ray glass materials were already added. You might want to see my separate V-Ray Glass Tutorial here.

In V-Ray for SketchUp you can actually use the HDRI both as a background and an IBL (Image Based Lighting). If you want to use the HDRI as background, all you have to do is to load it in the Environment Rollout/Background. If you want to use it as an IBL, then you have to load this HDRI in the GI (Skylight). This will become a light source then to
illuminate the scene. Alternatively, you can use the sun and HDRI together by using a Blend Map, but I won’t tackle this one here. The image below explains this clearly.

To load the HDRI, all you need to do is click the small “m” highlighted at (1) and then click type “Bitmap”, then on the Bitmap File highlighted at (2). Next  browse the location of the HDRI file in your computer (3).

You should select Environment UVW either cylindrical, spherical or box type (depends on the HDRI map type you have). In my case I have chosen spherical map, since I am using a spherical HDRI map. My setting is basically basic except for two things my physical camera and the Irradiance setting which has a little higher hsph subdivision.

Alternatively, do not even bother to use the physical camera since the HDRI will override the SUN which is a big Omni light. You will find that you don’t have to worry about balancing the Physical Camera setting and the multiplier of your HDRI. The only problem really is just syncing the V-Ray camera with the SketchUp camera. This is the reason why I used the Physical Camera. By using thomthom’s V-Ray Toys plugin. I was able to  sync the V-Ray camera and SketchUp camera. The image below is the render. The render is a bit dark, but you can see the reflection on the
environment. You can also see the rendering time is quick.

To lighten the image, I just increase the gamma of my HDRI both in the background and skylight. Saving Irradiance and increasing the HDRI Gamma to 1.2

Alternatively instead of raising the Gamma, you can also adjust the multiplier of the map or create an extra Omni light to lighten the scene. Again this thing is up to you. Finally, here are some more renders using different HDRI’s.

Cheers! I hope this tutorial is useful to you and look forward to sharing my next!

Nomeradona