This
Tutorial is to show you how to use the inexpensive thing to make the cool job.
This is my first HDRI-Tutorial, I hope it will help you. Sure, the technique explained
in this tutorial is somewhat inexact, that's because we use a very simple and
cheap way to reach the effect we are going for. However, this tutorial can also
how HDRI works in general.
HDRI
is th currently the thing all of CG is talking about. HDRI is the abreviation
for "High-Dynamic Range Image". It allows you to create realistic lighting
for your scenes.
We
all know the world the way we see it through our own eyes. Through the 256x256x256
steps of the RGB-colour setup we lose alot of colour-detail - now we can use HDRI
to intensify the impression of reality in CG-scenes.
Now,
follow me through this article and learn how I use HDRI the cheap way. Also I
will communicate some principle information on HDRI to you, so bear with me and
have fun!
Also
you need a stand for the ball, eg. the stick of a CD-R 100-pack is what
I use here
Now
find the some place you like, I used my work place's table.
Now,
put up camera and metal ball as on the image below. Make sure lens and ball are
on one level! I made that particular mistake many times, it messes up the reulsting
reflections, when camera and mirror ball are not on the same level.
Take
7 pictures from each positon (A and B on the image above); use different exposure
times, if possible. If you (like me) don't own a camera that allows for this,
it's ok to use "Exp.+/-" to achieve different exposure times, that's
not so exact, but it will
do to make your HDRI - so just do it !
Next
we need to open the HDR-Shop (download above)
Select
Create > Assemble HDR from Image Sequence. Loading the images we
took, use the calculate button (ignore the error infomation). Then save the generated
image. (Little Tip: If you find the generated image too dark you can change the
exposure steps using View > Exposure > Stop up + to adjust the images
and use the Pixels > Scale to Current Exposure to lock that steps light
image, this tip can help you to easily get the you want)
Another
little tip: you can use the ACDSee software to check the images detail:
Ok,
we have the DIY's HDRI put together, now you want to make the panoramic image.
You can find detailed tutorials on this on the official
site of HDR Shop.
After
merging the two angled HDRI, we get the panoramic HDRI. Now we can do the lighting
job. We need to open the HDRI maps as enviroment texture maps. Refer to this tutorial
to learn how to set up MEL files with the Lightgen-plugin.
Now
we finish our very cheap HDRI Render, by utilizing the good lighting tools "Lightgen".
Check
out the linked site below, you can download HDR-Shop there, it is a good place
to find more HDRI-Tutorials as well.
