soulslicer
Tank
- Joined
- Mar 16, 2007
- Messages
- 4,623
- Reaction score
- 12
I DONT UNDERSTAND THE BOLDED PART PLEASE HELP ME!!
"
REATING YOUR OWN HIGH DYNAMIC RANGE IMAGE
We can't explain High Dynamic Range Imaging any better than Wikipedia, so why try?
We're going to make our Half-Life 2 model reflect the colors and lights in our scene by lighting him with an HDR image of our scene. After the model is rendered, we can paste him into a picture of our scene and he should look like he belongs because his lighting and coloration will match the image's environment.
If you want to create your own HDRI file, you'll need a camera that can be set to different exposure times. Most digital cameras will do this. You'll also have to use a tripod because each image needs to be of the same thing and the camera can't move when taking long exposure images. You also need a ball with a mirrored finish. The mirrored ball is what you're going to be taking fourteen pictures of because it reflects all the colors and lights in your image. You can use a silver christmas ornament or get a garden ornament called a "gazing ball." We picked one up for about $10. The ball needs to reflect everything in the room or outdoor environment perfectly, so make sure it's round and has a metallic, mirrored finish.
We took seven pictures of the front of the ball and then moved our tripod to the side (90 degrees from our starting point) of the ball and took seven more pictures from approximately the same distance. Each picture was taken with a different exposure setting (each picture about 1 stop apart). Exposure is the length of time that the shutter stays open. You'll hear the shutter response take longer as you increase the exposure time. Your images should gradually get brighter and brigher as you increase the exposure time. The first image should be dark, but not so dark that you can't still see the brightest object in the image. Your last image should be bright, but not so bright that the entire image is washed out. We set our f-stop to 5.6 and did not change the camera's f-stop during this process.
NOTE: We took a few pictures of our scene without the ball in it so that we'd have some images to put our models into.
HDR SHOP
Next, follow these tutorials on the HDR Shop site to create your own HDR image:
* HDR Image Assembly
* Creating a Light Probe Image
For HDR Shop, we followed the tutorials pretty closely. However, after loading in our images, instead of calibrating our camera response curve, we left "Gamma" at the default value of 2.2. Being the trusting souls we are, we allowed HDR Shop to "calculate scale increments" by pressing the calculate button. We did not press any of those f-stop buttons on the right side of the dialogue.
For the second HDR Shop tutorial, we were perfectionists and decided to assemble our HDR image using two different views of our globe. However, we're pretty sure we could have just used one view of our reflective globe and called it a day. It would not have been perfect, but we're pretty sure it still would have worked and would have saved us an hour of our lives that we will never ever get back.
We found that our final HDR image was a little dark. To correct this, we opened our HDR file and used our keyboard's plus key to brighten it up. When it looked about right, we selected IMAGE>PIXELS>SCALE TO CURRENT EXPOSURE and resaved our HDR file.
"
REATING YOUR OWN HIGH DYNAMIC RANGE IMAGE
We can't explain High Dynamic Range Imaging any better than Wikipedia, so why try?
We're going to make our Half-Life 2 model reflect the colors and lights in our scene by lighting him with an HDR image of our scene. After the model is rendered, we can paste him into a picture of our scene and he should look like he belongs because his lighting and coloration will match the image's environment.
If you want to create your own HDRI file, you'll need a camera that can be set to different exposure times. Most digital cameras will do this. You'll also have to use a tripod because each image needs to be of the same thing and the camera can't move when taking long exposure images. You also need a ball with a mirrored finish. The mirrored ball is what you're going to be taking fourteen pictures of because it reflects all the colors and lights in your image. You can use a silver christmas ornament or get a garden ornament called a "gazing ball." We picked one up for about $10. The ball needs to reflect everything in the room or outdoor environment perfectly, so make sure it's round and has a metallic, mirrored finish.
We took seven pictures of the front of the ball and then moved our tripod to the side (90 degrees from our starting point) of the ball and took seven more pictures from approximately the same distance. Each picture was taken with a different exposure setting (each picture about 1 stop apart). Exposure is the length of time that the shutter stays open. You'll hear the shutter response take longer as you increase the exposure time. Your images should gradually get brighter and brigher as you increase the exposure time. The first image should be dark, but not so dark that you can't still see the brightest object in the image. Your last image should be bright, but not so bright that the entire image is washed out. We set our f-stop to 5.6 and did not change the camera's f-stop during this process.
NOTE: We took a few pictures of our scene without the ball in it so that we'd have some images to put our models into.
HDR SHOP
Next, follow these tutorials on the HDR Shop site to create your own HDR image:
* HDR Image Assembly
* Creating a Light Probe Image
For HDR Shop, we followed the tutorials pretty closely. However, after loading in our images, instead of calibrating our camera response curve, we left "Gamma" at the default value of 2.2. Being the trusting souls we are, we allowed HDR Shop to "calculate scale increments" by pressing the calculate button. We did not press any of those f-stop buttons on the right side of the dialogue.
For the second HDR Shop tutorial, we were perfectionists and decided to assemble our HDR image using two different views of our globe. However, we're pretty sure we could have just used one view of our reflective globe and called it a day. It would not have been perfect, but we're pretty sure it still would have worked and would have saved us an hour of our lives that we will never ever get back.
We found that our final HDR image was a little dark. To correct this, we opened our HDR file and used our keyboard's plus key to brighten it up. When it looked about right, we selected IMAGE>PIXELS>SCALE TO CURRENT EXPOSURE and resaved our HDR file.
