I'm using Carrara 2.1, I know it doesn't support .hdr files or true HDRI, but is there anyone who knows a way to mimic the effects of it. I' looked at all the threads in here for it, and I've found some, but they don't fully explain it. I've played around with GI and caustics and converted an HDR image and used it as a background, but the reults were far less than stunning. Any help would be great. thanks kaom

id like to know 2......i really want C3!!! with Transposer!

Here is a quick experiment I did. I don't know if it fits the bill at all, but here is how I got it (mind, the whole thing wants some work, I did it in a couple minutes). First I did a render with the GI and such, that looked nice, but not very crisp. Then I turned the backdrop to black (so it overwrites the background image I was using), and turned all the lights to zero, and removed all ambient light, etcetera. I then rendered it, and got just the reflections of the background, everything else was black. I took this image, and placed it over the first in Corel PP 9, using additive, so that it boosted the reflections, while adding nothing to the rest. As I said, it was a quick thought.

EMC

kaom, Agent Smith in Bryce forum looked into this for Bryce. As you'd be working with texture maps you might be able to convert his ideas here as the modeler shouldn't matter as long as it is capable of mapping a texture map to an object. Bear in mind there's two ways to go: a texture map of your object, or a large "universe globe" with the hdri texture on it . For non commercial use only you could check out hdrishop to create fake hdri textures. Perhaps It's a bit much to expect it to work the same way in Bryce and Carrara, but it would give you some ideas to play with anyway. - TJ

Thanks guys! How big was the image you used as a background on yur sphere,=? Reslolution(Pixels x Pixels - ppi)? Thats=;s kind of what I had in mind. Thanks kaom

And how did you apply the image to just half the sphere?

Attached Link: http://www.debevec.org/HDRShop/

Sorry, I've been dumb which is why I deleted my previous message. There's a much better way, using Environmental lighting: Add a sphere to your scene and make it large (600in in each direction). With the sphere selected choose Edit>Send to Origin. Delete all lights in your scene and set Ambient light to zero. With your Sphere selected switch to the Texture Room and add your image map to the glow channel. Zero out the color and other channels. Switch back to the Assembly Room, make sure your Sphere is still selected, then choose Edit>Environmental Lighting. In the pop-up window switch the Color to Object Glow and click OK. That's it, render with GI and Indirect lighting for best results. My example was rendered in C2. The bigger the better for the map. Mine was 1500 x 1500 pixels. It needs to be a proper latitude/longitude panorama. It's wrapped around the whole sphere (like a Mercator projection). If you get HDRShop (see link) you can convert any HDR file into a jpg or bmp that you can use in C2. Mark

Oops! The image map size should have read 1500 x 3000 pixels.

kaom: As to the size of the image, it was pretty small (maybe 800x800), and is my default GI sky light source image. The reflection in only half the sphere come from the entire lack of light in the scene. With no light, the objects will be reflected as black. This technique basically will only boost the brightness of the sky in reflections. EMC

Great tip, Falcon. So the texture map could be a Mercator projection of the northern (upper) hemisphere, 1500 high by 3000 wide, applied to either the standard assembly room sphere or a less-resolved vertex modeller sphere. Since either sphere is a single-sided surface, the backfaces (facing towards the origin) would project the same texture as the front faces (facing away from the origin).

Thanks for all the help guys. Does anyone know where to find some really good high res "(FREE)" HDRI images. I've found just a few, and they aren't high res. I've scoured with google, but I'm having a hard time finding them, I've found some of the Spherical but not the Long Lat type I need. I reaaly want to figure out a way to make Carrara 2 renders look as real as possible, and get the best wuality out of it. If I had the extra cash I'd get v3, but until then, I want to push v2.1. thanks kaom

Attached Link: http://www.debevec.org/Probes/

Mateo: the texture map is for the whole of the sphere. Actually, it doesn't have to be those proportions; if you look you'll see that the texture map for the preset shader of planet Earth is a square. And yes, you can apply the Environmental Lighting to a sphere of less resolution. That can be useful as the number of Anything Glows lights created for the standard primitive [about 260] can slow down the render time. kaom: HDRShop (which is free) will convert spherical hdrs to latitude/longitude. You can even use the program to make your own. All you need is a digital camera and a silver ball (such as a Christmas ball). One photo of a silver ball will actually give you a 360 degree panorama. There's a little distortion at the edge which HDRShop can get rid of with the help of a second photo but if you're not fussy about that, or the fact that you'll be in the photo, then one photo is enough. Picture number 1 shows a photo of my room reflected in a silver ball. Picture 2 is the Latitude/Longitude coversion done by HDRShop. This was saved as a jpg and then used for the Environmental Lighting in picture 3, rendered in C3. (If you look at the reflection on the sphere you can see the little amount of distortion, just left of centre.) I don't have any links to any really high res HDRs. But you can get away with a low resolution image if your main concern is the lighting and reflections. HDRShop will also covert the cross format to latitude/longitude and there are a whole lot of those at the link. The HDRShop site (link above) also has some in the tutorial section.

Falcon, just 1 more question if I may. Since you can only photograph the half of the mirrored ball facing you (the front hemisphere or top hemisphere), does that mean that, to get a true 360-degree panorama of your scene, you should photograph it from both sides? Then you would get both 360 degrees around the equator and 360 degrees in a great circle thru the poles.

Mateo: no, you only need one photo, because of the way any point on a mirrored ball reflects the whole of its surroundings. In principal though you get some distortion around the edge. If you look at my picture 3 above you'll see this distortion left of centre of the sphere. Compare it to the photo 1 and you will see that you can actually see quite a lot of detail in the render to the left of the window which is around the edge of the ball in the original photo. If you want to create a faultless panorama, and get rid of the photographer, then you do take two photos, but at 90 degrees. HDRShop can put these two together. If you're interested I could send you the photos so you can see how it works.

Maybe the photos will help, although it's hard for me to visualize how the side of the sphere facing the camera can reflect a point that's 180 degrees opposite the camera (in both polar coordinates). I can't use HDRShop (Mac OS), but if you want to IM me, I'll provide my e-mail address. The question of the sphere polygon count brings up two other questions. 1. Using a sphere's glow channel as the environment light source, would it average all the pixels of the region of the texture map associated in any given polygon, or would each polygon produce a variegated light that mimicked the variations in pixel brightness of that region of the texture map? Meaning that a 60-polygon sphere might produce a more uniform light source than a 360-polygon sphere, using the same glow map. 2. Is the HDRI engine in C3 also resolution-limited? Meaning it might average blocks of pixels in the same way as a sphere would, when used as an environment light in C2. One way to test this is to see if a 1500X3000 HDRI causes a render several orders of magnitude slower than a 150X300 HDRI. If not, then the HDRI engine may be limited to a low resolution, perhaps to avoid the slowdown that would be caused by having to calculate the effects of 4.5 million point sources.

Why do you want hdr images if you're going to convert them to a .bmp or jpeg? You're wasting your time converting a high bit depth image to a 24 bit one. Just use a 24 bit image to start with.

Thanks guys, I'm trying to come to grips with this whole thing. Is there aq difference between using a bitmap or jpg and using an actual hdri image? Do the HDRI images have light information? I'm still foggy with all of this.

JPG's and BMP's have three channels (RGB), with values between 0 and 255 (0 being black, and 255 being red, green, or blue). The GI in C2 uses 24bit images only. In a JPG or BMP or PNG, or whatever other 24 bit image type, clouds and the sun wil most likely both be white. The GI is done using the color values of the pixels, so the white clouds will cast as much light as the white sun. In HDRI, instead of a value between 0 and 255, the format supports a value between 0 and a one followed by 38 zeros (someone correct me if I'm wrong as to the actual number, but still, it's basically a really big number). This means that the clouds can look white, and the sun can also, but the suns actual value in the HDRI image can be much greater then that of the clouds, and therefore it will actually cast much more light. The only real difference between JPG's and BMP's is that JPG's have better compression, so that the files are smaller. EMC

Mateo: 1. I'm not sure about this. You can vary the quality of Environment Lighting but I don't understand exactly how this works: you'll have to ask Eric to explain. 2. The HDRI engine in C3 doesn't appear to be resolution dependent. It takes the same amount of time to render a HiRes hdr file as a LowRes. Kaom: The main difference between using an HDRI file and a jpg or bmp is the control you have (apart from any differences there might be in the way Carrara uses the files to light the scene). HDRI files have more information - the shadows and highlights have more definition - but it's not all displayed at once; it depends what intensity setting you use. The idea is to approximate how the human eye sees things (and therefore light scenes in a 'natural' way), within the confines of what a monitor can display.