I’m using composite composure to green screen in real time. The problem is I cannot get shadow for foreground object (see the box has no shadow on the floor). Does anyone know how to fix this?
Also, how do I capture the real life person’s shadow to key it in unreal environment?
If you’re capturing live-action you’ll need green under the object/person if you want their shadows.
In VFX they sometimes do an approximate CG character to match the basic placement and motion.
Adjust or split the shadow to control it independent of live-action.
This is the set up I have. The whole stage is green screen. Is it a problem with not enough light to get real shadow?
It’s tricky since you typically want even lighting on the entire green screen.
If you want true shadows you have to let some of them show on the ground (don’t fill in with light)
Same issue with your actors. They’re evenly lit so you wouldn’t expect many shadows anyway (assuming overcast area)
Other options are to take the matte you extract from the greenscreen map it onto the floor (as if it was on a card, imagine Photoshop corner pinning) You can then lengthen, shorten, soften and adjust darkness.
You can do the same thing by just use a gradation so it’s only showing their feet and lower legs. Blur that out to use a a simple contact shadow on the ground even for overcast shots.
Hi from Greece!
The subject of shadows and their integration might be tricky (or delicate if you prefer) depending on the situation. This is why, especially in your situation with an ‘over’ lit studio shot it would be easier to soften the lighting avoiding any key lights and blending with an HDRI or backdrop with equivalent - overcast lighting - which would ‘explain’ the lack of shadows.
If you wished to add shadows to blend the two anyway you need;
i.to add an equivalent key light to the one assumed by the set (in you jpg this would be from top/back and to the right/ try
ii.to add equivalent green geometry to the shot as that shown by the virtual space so your shadows fall as and where they should (this is especially difficult in your case unless you add a real pavement and railings to the left of your and ‘ingest’ them with photogrametry and place in the right of the shot.
I have not found a detailed resource on the sequence of thought for handling shadows on live shots. If someone has found one please shoot here. Maybe we should look into this
I would separate this problem into two areas;
Hope i added a little to your thinking - gotta go.
Unreal1ty Greece
