Forum: Carrara

Subject: Background Question

Eagle2358 opened this issue on Jun 06, 2004 ยท 4 posts

Eagle2358 posted Sun, 06 June 2004 at 1:13 PM

The top image is one of the HDRI maps included with Carrara 3; the bottom is a sky map I made in PS for the purpose of a background in Carrara to work as a reflection. It is tileable to the sides, but I am running into a problem with the top and bottom. When it reflects on a sphere, the texture map comes to a point at the top and it is very noticeable. I was wondering if anyone knows how to stretch the top and bottom to the sides to compensate for this effect (I hope you know what I am talking about...I could include some more pictures). Notice how the top and bottom of the HDRI map stretch out so that the map correctly fills the large sphere it is mapped onto with "background." Any help would be appreciated, thanks!

kaom posted Sun, 06 June 2004 at 2:39 PM

I think you need to use HDRShop, I shoot pictures of gazing balls and convert them in HDRShop to longintude/latitiude maps... I don't know if you can use a regular tileable image and have it work right.. HDRI images are a whole other ball game than regulat tilaeable stuff... 2 different worlds..

falconperigot posted Mon, 07 June 2004 at 5:19 AM

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

As kaom says, you can use HDRShop for this. It's a good program for manipulating Low Dynamic Range (LDR) images as well as HDR - and is free (but is only for Windows unfortunately). 1.Start HDRShop and open your sky map (this must be 2 x height = width). Use the default settings for gamma etc. 2.Choose Image>Panorama>Panoramic Transformations. For the source image format on the left choose Latitude/Longitude. For the destination image choose Mirrored Ball. Change the pixel dimensions of the destination image to half width+height of your original. This should avoid too much interpolation. Click OK and then save the result as a LDR file. It should look something like there top image above. 3. Load your new image into Photoshop and use the clone tool to get rid of the two distorted areas. 4. Reverse the process in HDRShop. Load your new image, choose Panoramic Transformations. Choose Mirrored Ball for the source image and Latitude/Longitude for the destination image (same pixel dimensions as your original). Save the result as a LDR image, load into Carrara as a Background and enjoy! HTH Mark

Eagle2358 posted Tue, 08 June 2004 at 12:48 AM

Hey thanks that works great.