Camera matching and SL.

[Iya Rankin]

Hi all,

I want to create a short film using RL and SL footage.

I'm struggling to figure out how to match my SL camera angle to the camera angle of my RL video footage.

I want to seamlessly cross fade from RL to SL footage as if the room i am standing in suddenly changes from real to animated.

Also, what if camera tracking is involved as opposed to having a locked off shot on a tripod.

Can anyone offer any insight on this subject?

Edited September 4, 2021 by Iya Rankin

[Wulfie Reanimator]

I'm not a huge camera person, but probably the most important aspect of composing two different shots together is focal length, or the field of view.

The RL camera you're using indoors will most likely not match the focal length of the default SL camera. You should be able to press Alt P to bring up Phototools in your viewer to tweak the relevant settings, or adjust your RL camera.

There's a bunch of things beyond that (like lighting, depth of field, the tracking, etc.), but I don't want to get into those right now. Hopefully someone else can.

Edited September 4, 2021 by Wulfie Reanimator

[Jenna Huntsman]

5 hours ago, Iya Rankin said:

Also, what if camera tracking is involved as opposed to having a locked off shot on a tripod.

With a bit of LSL you can take control of the camera and have it interpolate between locations. There's tools available on the MP which allow you to do this if you don't want to get your hands dirty. Alternately, some TPVs have Machinima controls which can be used to do this.

But yeah. What @Wulfie Reanimator said - you need to match your virtual camera to that of your real one. Essentially, you need to match the focal length of your real camera (e.g. 35mm). Some viewers have this pre-programmed (I think Black Dragon has lens presets built in, but I may be wrong).

Lighting! This is important, and something that many get wrong in SL as it's a little hard to wrap your head around. Lighting in SL revolves around 8-bit RGB, and thus you'll see many lights which are just pure white (255,255,255) - but lights in real life are pretty much never pure white, instead they lie somewhere on the Kelvin scale. For example, the traditional filament lamp is in lighting terms, a 'tungsten' source, thus has the colour temperature of 3200k. LEDs can vary wildly, some can be 3200k (often called 'Warm White'), or 6500k ('Cool white').

The colour temperature of daylight is also variable, but generally on a clear day it's around 5300 - 5600k.

To translate all of that into SL terms, you need to convert from Kelvin to RGB. Fortunately, that work has already been done: https://andi-siess.de/rgb-to-color-temperature/

Another thing - think about the types of lights in the room. A regular table lamp will have a lamp shade, and gaps above and below. In SL, that means you have to use projector lights in order to get the same kind of beam pattern on surrounding surfaces as would be the case IRL.

Final thing - remember that also your environment preset also adds it's own light, again, often assuming that sunlight is 'pure white', 'orange' or 'blue'. (The Linden presets fall foul of this, which is why much of the Mainland and Bellisseria looks so washed out). 

All things to think about. Match your camera settings, your movement and your lighting and you'll have most of the work done.

Edited September 4, 2021 by Jenna Huntsman