Again, appologies to the old hands if this is a simple question.

I am playing around with IBL in C6, and I was wondering if my theory about creating IBL for the exact scene I am working on is a possibility.

I havent tried yet as I am lacking all the skills to do the job, but I want to know if I am on the right track.

If I wanted to set up a scene that containes something shiney, lets say a car (I have watched Marks dark arts tute with the IBL) but instead of reflecting random stripes on the car from a photoshop hdri image (like Marks dark arts tute), could I create an image/render using C6 spherical camera placed in the center of my scene to create an image that can then be used so that the reflections actially imitate the scenes surroundings?

I guess the steps would be:

1. Set up the scene and place the regular lights, spots props or whatever.
2. Insert the spherical camera, hide the shiney vehicle (that was in the center of the scene so its doenst show refelctions of itself) and create a render from that camera.
3. Use photoshop or similar to convert that render into hdri image.
4. Use the image in the scene Background-HDRI to ensure the shiney object in the scene has the correct reflections from the scene.
5. Adjust the scene non hdri lights to obtain correct or realistic levels.

Am I talking nonsence or is this an acceptable method to creat scene lighting and realistic scene reflections?

 Hi nobrot,

Very easy to do - except if your scene is inside a room since IBL is created as a giant sphere that is larger than the Carrara workspace - it won't shine through walls. ;)

Build your scene and then place a spherical camera in the middle of it. It takes a little bit more fussing with the camera elevation to get it perfect so put the resulting render in a new scene as a background element with a reflective sphere in it for proofing. If everything looks ok, then do the HDR work and your set. 

HDR/IBL, when used in a scene, is best for scenes that actually have no props. The whole point is to let the map do the work. Creating a scene that has the same props in it as the HDR map will lead to double reflections.

Mark

Thanks for the quick reply Mark. One thing I didnt realize, being the 3d infant I am, is that the shaders actually reflect the scene anyway. This has confused me, as I was thinking that you had to have HDRI map to crate reflections in shiney objects inside a scene.

I have done some testing using reflective objects in scenes that have realistic sky, and all the reflections seem to be reproduced flawlessly.

I need to play around more, as I am confused about the relationship between regular scene lighting, HDRI/IBL and object reflections.

Well I havent had much success here, I am obviously making a fundamental mistake.

Here is what I have done, I would be very gratefull if anyone can help me sort out what I am doing wrong.

Objective is to take a scenes standard lighting and change it to IBL using an HDRI image generated from within the scene itself.

First thing I did was to open a pre-set scene (Dream Islands) and insert three spheres with variouse textures, I then rendered this out and saved the results.

I then inserted a spherical camera in the scene, positioned it a little above the terrain and rendered the image. I then created an HDRI image from this render using HDRShop.

The next thing I did was to change the scen effect Atmosphere from Realistic Sky to None
Select the Scene Background as HDRI and loaded the image I created in HDRShop. I then turned off Light 1 so it wouldnt interfere with the IBL.

The attached image is the resulting render, as you can see the sky is messed up showing what looks like large chunks of the hdri image, and the lighting is a lot softer than the original image.

Thanks again.

 

The scene background (your HDR image) will render as the background of the image. Here is where you might place an HDRI of the sky or other back ground scenery.
Remember to keep the image proportions of your render the same ratio as your background image. Otherwise it warps.