LIghting question - Bal A Versailles

ibr_remote aka infinity10

I am using iRay to render , and I have added emissive shaders to the light bulbs, plus assigned clear glass shaders to the glass parts.  I used a noon-time HDRI image mapped to the skydome of the backgrond.  I stil cannot get an adequately bright scene to render.  Apart from the extra time to render, extra samples, blah blah, any further suggestions, please ?

 

 

 

Fishtales

Adjust the camera settings in Tone Mapping to allow more light into the lens, as you would for a real camera.

Patroklos

When rendering there are 2 elements of lighting to consider. First is lighting the scene brightly, even if the final result you want is subdued lighting. This is because IRAY works fastest and best on a brightly lit scene. Once you have your brightly lit scene, you then subdue the appearent lighting (what you will see in the render) by using the camera controls.

 

1. To keep the time required to render down to reasonable levels you must keep the number of lights down to the minimum required to get the effect you require. This is because IRAY has to calculate what each invidual light will add to the scene. More lights = more calculations = more time. So adding unecessary lights will slow you down. I am careful about this as my machine does not have an Nvidia card, so rendering is slow.

2. you can increase the light level of the HDR - go to Render Settings / Environment / Environment lighting resolution. A Setting of 10 (which is pretty high) will give you plenty of light which keeps render time down.

3. Once you have done the above you may well find that the picture is very bright - that is good - lower render times. To make the picture/render look right, go to camera, make sure the headlamp is OFF, Then go to camera and use the shutter speed, f stop and so on to make the render look as you wish.

It really is like you would do in a pyotography studio, light the scene well and then adjust your camera to get the shot as you like it. The difference with rendering on IRAY is you can control the outdoor light level in the same way, by cranking up the HDR Environment lighting resolution as mentioned above.

chris-2599934

Patroklos said:

To keep the time required to render down to reasonable levels you must keep the number of lights down to the minimum required to get the effect you require. This is because IRAY has to calculate what each invidual light will add to the scene. More lights = more calculations = more time.

Whilst that's certainly the case in 3Delight, I've found it not always to be true in Iray. What an Iray render seems to really hate is areas of shadow - if adding a light eliminates a shadow, it can make the render faster, not slower.