Chrome Ball For Hdri Where To Buy
With your slate captured, next shoot your reference (grey ball, chrome ball and Macbeth chart). Ideally, your reference would be shot from the same position as to where the camera/CG is as this will give you more accurate reference, however, this may not be possible, so just get it as close as possible. Try to get a good mix of light and shadow on the grey ball as this will give the lighting artist more info when tryng to match exposure.
chrome ball for hdri where to buy
For a quick and dirty way to make a HDRI map, you can shoot bracketed shots of a chrome ball - merge the images into a HDRI and then convert it to the lat-long format. Or many software packages support this 'probe' image format, which is a tight crop on just the ball within the shot, so you don't have to convert it to lat-long. But lat-long is my preferred format to work with.
The process is very simple. Place the chrome ball in the center of the location you want to capture. Shoot it from the location where the camera will be placed for the actual shot. You will get the best resolution from the area of the chrome ball facing the camera, and the edges of the ball will produce a far lower quality blurry result.
Cost: You can use your existing camera, as long as it can shoot bracketed sets of images. You can make a chrome ball from a Christmas decoration and other chrome ball items you can find, but there are chrome balls available specifically for this. Here is one for sale here on ebay priced at @155.
HDR Light mapping is a technique used to get accurate lighting results when putting 3d models or characters into a photo or video scene. By taking photos of a chrome ball, you can take the reflection data, do a bit of magic to turn it into lighting data, and apply this to your models, to make them look like they belong in your scene.
As part of my test with the Canon 5d camera i also tried to develop a workflow for Image based lighting, using HDR images from a mirrored chrome ball to obtain photorealistic 3d lighting that match the live conditions. Using that you can insert any 3d object with proper modeling and materials into the scene and they will fit in quite photorealisticly.
After some research people tend to use chromed balls from garden supplies shops quite a lot. I first got one that did not have a perfect surface, but luckily ma uncle is a landscape and garden designer who just got a brand new shipping of those chrome balls in all kinds of sizes and flavors up to mirror balls with almost 80 cm in diameter. I got myself one with 15 cm and another handy one with 10 cm, additionally to the old one i used for the test.
The tricky part in this whole operation is getting the setup right in your 3d software. Im not going too much into the details here, but in 3d Studio max its a combination of Mip rayswitscher, mip camera map, the environment/chromeball shader in the environment map and the matte shadow material in order to get proper shadowing and colors on the surroundings in the video using dummy objects that receive those shadows. All is done using the mental ray rendering engine.The mip Rayswitcher is important to switch between a high resolution chromball image for reflections and a blurred smaller version for the lighting. As for lighting a blurred smaller version is preferrable, because a non blurred version with high details can give you problems, because of sampling issues.
Here are some examples, where i just wanted to check how applicable this is for different light situations using (basic) matchmoving. What i found helpful at times was to paint out the sun itself from the Chrome ball, so that you get the ambient lighting from the environment, which final gather can handle quite well and then use a non physical light as a keylight in order to mimic the light of the sun. Those shots come directly out of the renderer, i did not do any compositing, in production i would have rendered out some passes in order to get further control for shadows, motion blur and the 3d objects themselves.
This video collection will walk you through creating your own high dynamic range images. And not only just getting an HDRI we look at what makes an HDRI more realistic, stylized, and more interesting for your lighting. We begin with the equipment necessary to create an HDRI image. We cover two methods of gathering the initial images. First the chrome probe ball used in gardens everywhere. Next the fish eye lens which can gather 360 degrees of your view. After you create several HDR's you'll be matching the lighting in your video footage or just enhancing your studio lighting in no time. Software required: Photoshop CS5, HDR Shop, Maya 2012.
The next stage for setting up the scene was to create my Image Based Lighting (IBL). An IBL is an ambient lighting system that maps physically accurate environmental imagery onto a sphere that surrounds the scene. Each pixel has a luminance value determined by its colour. These values are projected inwards, producing realistic environmental lighting. This is particularly necessary for highly reflective objects that capture the surrounding environment. The image used for an IBL is a High Dynamic Range Image (HDRI). A HDRI is a series of images taken at different exposures, condensed as a single image. It provides a high range of information as it captures both the light and dark points within an image. A good way to capture the environment in an image is to take a photo of a chrome ball. This highly reflective sphere captures the environmental information which can be remapped onto the IBL.
The last process in photoshop was cropping my HDRI to the boundaries of the chrome ball. When it comes to flattening the image, it is important that the image is perfectly square. Therefore, under the image menu settings I selected image size and unchecked the box for constrain proportions, then changed my width to be the same value as the height. 041b061a72