Hi all, i'm trying to make a realisic blood shader. Don't ask! It needs withstand close inspection as the camera is very close. It also needs to look good when moving as the shot is around 100 frmes long. Any ideas would be great.
JT
Full Version: Blood shader?
Depends on the shot, as usual. Little droplets splattering, Freddy vs Jason gorefest with huge gobs flinging past camera, microscopic realistic documentary showing hemophilia, high/low contrast, backlit…all different challenges. 
Also, whether you want it to “look” like blood, or it's a documentary and it needs to look right to a doctor. In his black and white samurai films, Kurosawa always used chocolate syrup - it came across looking more like blood than coloured opaque water. The fact is, though, blood is incredibly runny like water and isn't thick at all unless it's started to congeal. It's audience perception vs reality - we like to think blood is thicker than water. 
Well, it is of course, but not as much as you might think.
As memory serves blood is quite opaque as long as you have a certain amount of thickness of it and tends to read like water in terms of reflection passes and well, is opaque red otherwise. There would be subsurface scattering tho if backlight.
As far as motion - again…it depends. Dripping down a wall? You might want to look at metaballs animated, converted to polys, then clipped. I've done that before and I needed to hand animate them a lot because particles can drive you nuts, control-wise.
I won' t continue 8) - maybe you can give a little context?
Cheers,
J.C.
Also, whether you want it to “look” like blood, or it's a documentary and it needs to look right to a doctor. In his black and white samurai films, Kurosawa always used chocolate syrup - it came across looking more like blood than coloured opaque water. The fact is, though, blood is incredibly runny like water and isn't thick at all unless it's started to congeal. It's audience perception vs reality - we like to think blood is thicker than water. Well, it is of course, but not as much as you might think.As memory serves blood is quite opaque as long as you have a certain amount of thickness of it and tends to read like water in terms of reflection passes and well, is opaque red otherwise.
There would be subsurface scattering tho if backlight.As far as motion - again…it depends. Dripping down a wall? You might want to look at metaballs animated, converted to polys, then clipped. I've done that before and I needed to hand animate them a lot because particles can drive you nuts, control-wise.
I won' t continue 8) - maybe you can give a little context?
Cheers,
J.C.