View Full Version : What info do I need to match CG and reality?

10 October 2004, 01:31 PM

I am currently working an a cg-animation that will be combined with a stopmotion-video.
So I need to get certain information from the stop-motion set.
I thought about the following list:
1. A gradient from white to black printed on a piece of paper and photographed on-set, for capturing the lightcolor.
2. a white paper with a grid of black lines, to match the orientation of the floor.
3. A cube ( should it be white? ) on a white paper to catch the shadows.
4. a floorplan, that show all lightsources, the camera, the props , and the set.
5. All data that there is to know about the camera.

Some questions :
Do I need a lightintensity meter? ( like those used by photographers?)
Did I miss anything that could make life easier? ( for composing the scene)
Thx in advance

10 October 2004, 06:43 AM
Have a look at there are some great intervies with vfx supervisors about tips and techniques.

Things I generally take to set with me :

The 'old' grey ball...some like white ! = for light direction and colour
NB if you have one a maquette or model of your 3d objects is even better !!

a chrome refelctive sphere : for capturing reflections

a tape measure : measure every thing and draw diagrams to help you later.

an inclinometer : measures the incline angle of the camera. If you don't have one you cinematographer or focus puller might!

a macbeth colour chart : a standardised chart of colours shot at the start of a roll of film to ensure colour consistancy in film.

a digital camera: for panorama's bg plates and to take photos of lighting and camera setups.
shoot whatever you can in between takes !!

a black grid chart: to check for lens ditortions

felt markers in a few colours : you never know when these will come in handy
a notepad with all relavent paper work.

you won't need a light intensity meter. you should eb able to get this data from your cinematographer.

if you need tracking markers here are the two designs that I generally use that I find work best !

10 October 2004, 06:14 PM
Hey Aneks, those are some great tips!

-- why is the + marker "tilted"?? I'm sure it's intentional and that it has a benefit, I just have no clue why...

- Jonas

10 October 2004, 12:45 AM
Normal "+" trakers can work fine in most circumstances. But I have started using these for 2 reason:

-i've found that many optical trackers can introduce a slipping error when tracking from a conventional cross. That is they can confuse the straight horrizontal line or vertical line and shift along this instead of focusing on where the two points converge. This is aggravated by extreme motion blur !

- second if the tracker is partially obscured when using the typical cross tracker, then you could be left with an "L" shape or some variation of... This design gives more options for a unique pattern for a tracker to lock onto !

10 October 2004, 07:28 PM
Excellent information. Bravo.

11 November 2004, 11:10 AM
Hey thanks for the awesome tip/
my otherquestion would be.. how do i make the reflection map through the chrome ball ? Does it have to be HDRI ? I'm a newbie and is trying to do one assignment on that.
As far as measurement is concernt. What should i meeasure ?


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