Hi all, I am wondering if it is possible to create Virtual Probelight images, similar to the handful of such images that come with P6 ? I tried doing this with the HDRShop (Image/Panorama/Panoramic Transformations) using a standard image as input (Cubic, vertical cross I think) and a mirrored ball as output. It created something but didn't really look right. Thanks in advance. regards, Andrew

Please correct me if I'm wrong but the lightprobe images in P6 are Low Dynamic Range jpegs. They don't appear to be HDRShop processed because you can still see the photographer in them and P6 does not directly support *.HDR files. Lately I've been using a sphere with mirror material in Vue 5 Infinite, building an environment around it, HDRShop + Lightgen plug-in, loading resultant image as P6 IBL adn pleasantly pleased with the result.

"Please correct me if I'm wrong but the lightprobe images in P6 are Low Dynamic Range jpegs." You're correct. "They don't appear to be HDRShop processed because you can still see the photographer in them" There's tons of lightprobe images out there that have been run through HDRshop that still have the camera in the image. It just means the creator didn't take the time to clone out that part, it has nothing to do with it being processed in HDRshop or not. I'm not even sure HDRshop can do it if you wanted to. I think you have to use an image editor to clone it out. :-)

Thanks, guys. I'm not really interested in whether you can see the photographer in them or whether its HDR or LDR. I just want to know how you can create them, starting off with a flat image.

Attached Link: http://www.debevec.org/HDRShop/tutorial/tutorial4.html

to maxxxmodelz: I'm not even sure HDRshop can do it if you wanted to. Actually, the HDRShop tutorials contains a section with your two images at 90 degrees apart and painting a photoshop mask to combine the two images together. Haven't tried it yet. Argh, x-post. To mathman: I'm no expert but all the images (in the url)appear to have spherical distortion, an artifact of photographing the mirrored ball. Have you tried to create an IBL and point it to your flat image? At work now so I can't try it :)

Thanks for the link, replicand. I'm trying to work out how to go the other way, i.e. create a mirrored ball from a flat image. If you start off with some arbitrary flat image with no symmetry e.g. a landscape created in Bryce or Terragen, how do you convert it to a mirrored ball ? What do you mean when you say "Have you tried to create an IBL and point it to your flat image?" ?

"How do you convert flat image to mirrored ball?" Someone else may have to field this one because I'm not sure if it's possible. Maybe lots of photoshop-ping but that seems like a lot of work. As a Vue5I user, I can't comment on Bryce / Terragen capabilites. I wanted to use image based lighting in Poser but create my own lightprobes. I don't have a camera so I decided to create them virtually, using techniques from face_off's website I create an environment in Vue. Create mirrored ball. Render (what will become in Poser) the background as a jpeg image (mirror ball hidden). Unhide mirror ball and render it as hdr. Load it in HDRShop + Lightgen plugin and reduce it to jpeg to be used in Poser. Open pose, pose figure, /Material Room wacro/ create IBL will open a dialog box asking for (in your case, flat) image. Render. Off topic, there is a post in the Vue forum where someone used Vue's IBL feature to light a poser figure using just a plain white bitmap. It looked really good in Vue but didn't try it in Poser (too busy with environment lightprobes). Long winded but I hope it helps.

I think panoramic renders in Vue 5 are the same as Longitude/Latitude images in HDRShop so you can: 1) render in Vue a Panoramic view (360) (in Render settings); 2) load the render in HDRShop and transform it (in Image>Panorama>Panoramic Transformation) from Latitude/Longitude to Light Probe; 3) use the Light Probe in a Poser 6 IBL. Yes, Poser 6 use LDR images only, not HDR, but you can apply the above transformation in HDRShop to LDR images too: it involves the geometry of image, not its lighting informations

Thanks, marco and replicand. Only problem for me is that I don't have Vue.

"I'm trying to work out how to go the other way, i.e. create a mirrored ball from a flat image" It really doesn't have to actually look like a mirrored ball in order for P6 to use it as an IBL, just so long as your flat image matches the IBL coordinates fairly well, then it will light the scene just fine. IBL data is distributed to a scene via specific coordinates in the IBL image. It has nothing to do with it looking like a sphere or ball really (it has more to do with what is inside the circular area of the probe image). Do a search for IBL here, and if you're lucky, you'll find some nice 'blueprints' of how the IBL maps work (ie.; what parts of the image used actually lights what parts of the scene). I think Mec4d and Nerd have made pretty accurate diagrams that lay out the specific areas (top, bottom, sides, back, etc.) of how P6 reads a "probe" image.
Message edited on: 07/28/2005 06:40

You could use a "light gel" a texture applied to a light to simulate IBL, the picture would probably need to be made blurry but it should work and would work in poser 5 as well as 6.

"You could use a "light gel" a texture applied to a light to simulate IBL, the picture would probably need to be made blurry but it should work and would work in poser 5 as well as 6." The problem with a gel light is that it's still "directional", and will not light the entire scene 360-degrees like IBL.

You could use four (or more) lights with the same texture applied to light the scene from all directions.

"You could use four (or more) lights with the same texture applied to light the scene from all directions." I see what you're saying, and while that may provide an interesting effect, it's not anything like IBL. Reason being, if you use the same texture map as a gel on lots of lights in the scene, then you're going to end up with the same colors all over the scene in a "grid-like" fashion, depending on the locations of your lights. It will light the back of the scene exactly the same as the sides, and the front, which isn't going to be as realistic, especially if you're trying to match a background image. A diffuse IBL light, uses zones (top, sides, back, front, bottom) in it's template to administer the light in a single image evenly to the entire scene according to the colors that are present in it's zones. For instance, if the bottom of your IBL image is green, then the scene gets lit green from the bottom, and so forth with all the zones in the IBL. One way to fake this is to use Stewer's "Poor Man's HDRI" script and HDRshop with the lightgen plugin to create an array of spots for Poser that correspond exactly with the colors in an image. It will output a file that's readable by a Python scipt to automatically create the lights to the proper intensity and colors. This works, but is only partially efficient, since there's going to have to be at least 40 lights in the scene to get a smooth result. Rendertime will obviously take a hit. A diffuse IBL light will render VERY quickly by comparison, since it's really only one light. It will slow down, however, once you enable ambient occlusion, which has to be raytraced.

I understand that, but you can place the lights selectively so that some parts of the scene are not lit that way. For poser 5 users it is the only way they can try this effect.