Starting HDRI, well where to start?

[Morne]

Hi All

There seems to be a lot of hype lately regarding this issue and it seems there are a lot of information out there on the subject. So here is my stupid question of the day: where do I start with HDRI? Is it mainly for exteriors or can I use it for an interior also (with no windows or openings)? Any pointers to some HDRI starting off tuts for VRay? Can you still use HDRI with methods susch as LWF and Bernhard's RWF or is HDRI a "workflow" all on its own?

Kind Regards,
Morne

[instinct]

HDRI alone doesnt have anything to do with interiors, exteriors LWF or alike. HDRI - High Dynamic Range Image....and that's what it is...an image...be it rendered or a source file for rendering...it's an image...

Regards,
Thorsten

[Morne]

I was thinking in the lines of people using HDRI images to light their scenes. Or do I now totally have the wrong end of the stick?

[MikeHampton]

No you can use HDRI images to light your scene and/or be the reflection map for the scene.

I haven't done this very much other than with just some quick experments with it. Mostly I see it used to illuminate an exterior, or just to illuminate an object (matching it to the illumination of a live action shot), or as the exterior light comming through the windows to illuminate an interior. I have not seen anyone use an HDRI image to actually illuminate an interior inviroment (other than just the light comming through the windows). I think because all the objects in your scene (starting from the floors/walls and ceilings) are going to block your illumination comming from the HDRI map.

So not saying it's not impossible to illuminate an interior environment.. just that I don't think I have seen it done, so if it can be done.. it's probably much more difficult to set up.

I'm sure someone who has more experience in doing this can add to this. But basically you just put the HDRI map into the Vray GI enviroment override slot. If you want to see the HDRI map in the background of the rendering.. you need to also put the map in the max enviroment map slot.

If you load the HDRI map into any material slot you will see a HDRI load settings dialog box. You can use this to set the absolute black point and the absolute white point values for the map. What number you get in the linear box of the white point value you can put this into the RGB level in the Output of that map. Copy this map and instance it to the Vray override slot. Experiment with the multiplier value to get the level of illumination you want.

That's all it takes for the HDRI image to illuminate your scene/object.

That's all I've done with it so far. I'm sure others can add it more info.

[instinct]

It's a matter of what you do i guess. It's fine for interiors when you have to put something in a photograph of an interior for example. It's a vast field. And the possibilities HDRIs give you in post when rendering them is just as big as the use to light a scene i'd say. For reflections they are a must if you are using a reflection map :P

Regards,
Thorsten

[Morne]

Thanks for the info guys!