HDRI with vray, dome area

Author: Simone Manna

Often I read of several lighting techniques for the exterior with vray, surely one of the most popular along with that of the physical sun and sky is lighting with HDRI with vray, dome area.

Meanwhile a small way, what is HDR? HDR stands for High Dynamic Range (wide dynamic range). It 'an image format (.hdr file) that contains more information than a normal depiction. It consists in photographing the same subject at different exposures so as not to burn the light areas and not darken too dark areas (in short ..). This allows you to have a photograph completely balanced, this type of technique is called just HDR.

In 3D HDR images have the function, if properly associated to sources of light, to illuminate a scene taking into account all the information that this image contains, with lighter areas where the image is clearer and vice versa.

In Vray HDR images should be attached to the dome lights area . I am using the conditional only because I often saw use nell'enviroment of vray, but in my opinion does not have the same quality of light area in the shadows.

Let us see how to activate it through a few steps:
The image that I will use is a free download from hdrmill.com

In the scene, we put first and foremost a physical camera * and we set as shown. Let's add a Vray Light. In the panel choose Common Area Light, intensity and 100 * Enable Shadows.

Image Courtesy: simonemanna.it

Image Courtesy: simonemanna.it

Panel Area Light choose from the menu Dome.
spuntiamo Spherical Dome and Use Texture , then we load the textures .hdr into the appropriate field. Basically the HDR so is set. At this point everything is refined, starting with the subdivisions of the shadows Light area default is 8, bringing to a minimum of 24 to have shadows cleaner without disturbance. It is also possible to adjust the parameters by increasing or decreasing the exposure, and contrast using the dark spot and the white point.

Image Courtesy: simonemanna.it

Image Courtesy: simonemanna.it

By setting in this way the hdr images are obtained with diffuse light, coming from the right image properties, both as regards the lighting that any reflections on objects of the scene.

A quick example is as follows:

Image Courtesy: simonemanna.it

In addition to lighting widespread HDR dome area, you can use a physical sun.

You can do this by adding a light to the scene and, using the tag, set the physical sun (if necessary I wrote a guide long ago that you can find here ), trying to give the same direction in light and shadow following the hdr we use .

Image Courtesy: simonemanna.it

* As usual, the intensity of the lights or the use of phCam depends a lot on what we want and how we are used to working. Without phCam, for example, the value of 100 in the dome is definitely very high, everything must be calibrated always if we use it or not and how we use it in the case:)