HDRi background

Hi, when we convert a background to HDRi do we have to use it as HDRi, backgroung image or both?

Regards,

Replies to This Discussion

Permalink Reply by Render Plus on March 17, 2011 at 12:03pm

It can be used as an KDRi Planar background, or as an HDRi sky.

However, the images itself may need to be different. An HDRi sky is assumed to be a complete 360 panorama. It can beused for visible sky, lighting and reflectios.

An HDRi Planar Background is assumed to be a flat image. It is not used for lighting or reflections. One of its values is that it works better than just a background image, and that you can adjust its intensity using Lighting Channels.

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Permalink Reply by Alain Bonnefoy on March 17, 2011 at 12:07pm

So when the background image is set to "visible", do we see the HDRi image or the background?

Is it possible to use HDRi image for light only and the background as visible landscape?

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Permalink Reply by Render Plus on March 17, 2011 at 12:09pm

You can use an HDRi sky for light , with a different background.

An HDRi Planar background is not used for light or reflection.

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Permalink Reply by Alain Bonnefoy on March 17, 2011 at 12:17pm

ok, so why to convert it to HDRi?

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Permalink Reply by Render Plus on March 17, 2011 at 12:34pm

The Planar HDRi can be used to brighten or darken the background using Lighting Channels.

Because it is an HDRi image, and not just a normal image, when you darken it, it will not darken uniformly (as it would it a paint program). Instead, the lighter places - which are expected to be lights - will darken more slowly.

I am working on a sample image showing how to adjust the Lighting Channels for an evening sky for the other thread: http://irendernxt.com/forum/topics/evening-sky

I will post an example there when it is done.

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Permalink Reply by Alain Bonnefoy on March 17, 2011 at 12:36pm

ok, very good.

thks

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Permalink Reply by Boothy on March 17, 2011 at 2:21pm

Hi Al

Can we import HDR files direct into background yet?- I keep trying\testing with no result - Is there a definitive tutorial for HDR backgrounds/ I just cannot get any image to work consistantly and on the few occasions I do get background to convert HDR\work the minute variation in tone in image editor is a completely useless.

Half the time the backgrounds do not appear in renderer - really do not know what I am doing wrong

Any help gratefully received

Boothy