Shadows?


(Dion Moult) #1

I dont know why, but when i first started modelling the lab for my animation (view The Next Gen Technology in WIP), there were shadows. i suppose it is default. but recently during renders (i have changed a lot) i have realized that there are no more shadows!

can you list all the things that make shadows work? because i really need those shadows.


(Marty_D) #2

Did you turn ray tracing off? You might want to post your blend for dissetion if the problem is more complicated than that. What kind of lights / lighting are you using?


(Dion Moult) #3

no my raytracing is still on.

im just using lamps.
here are my lamp settings:
http://e2-productions.com/resources/misc/uploads/33.PNG


(nico) #4

Your settings show that RayShadows are disabled for your lamp, so just click on that button.

I still recommend to use buffer spot lamps, as they can give soft shadows are calculated much faster.


(Marty_D) #5

Two things. Firstly the button that says Ray Shadow in the “Shadow and Spot” panel. For standard lamps to cast shadows you’ll need to turn that button on. And then secondly the Sphere button. When enabled sphere limits the distance that shadows are caluculated so you may want to leave sphere disabled initially and then when you have shadows working re-enable the limiter in order to achieve distance fall-off simulations. Does that help?


(Dion Moult) #6

yeah but the problem is: my light sources are candles.

so if i change that it ruins the candle effect… :frowning:

help?


(nico) #7

What do you mean by candle effect?

I don’t understand who any of the tips would ruin anything, unless you talk about sharp shadows.


(Marty_D) #8

Man, nico types fast. :slight_smile:

For a decent candle effect you could use the standard lamp with shadows turned on and set the intensity to 25% of the total brightness you’re aiming for. Then, clone the lamps, ALT-D, 3 times and offset the lamps just a little. This will give you a quasi soft shadow.

The area light uses the same technique; that is it merely adds more lights to the calculation.

The more lights you add the higher the quality of the shadows. And also the higher the amount of time it will take to calculate and render the scene. :slight_smile:

Spotlights are also slow if they are raytraced, and they are raytraced if raytracing is turned on in the scene, because they have soft shadows. But they are directional. For a candle a point of light is desireable. There are tradeoffs for everything.


(Dion Moult) #9

The more lights you add the higher the quality of the shadows. And also the higher the amount of time it will take to calculate and render the scene

well. yeah after testing it out yes your right it doesn’t spoil the “candle effect” (see my intuition sucks).

yeah i have four candles and 8 lamps in the scene. and it just took about 3 minutes to render.

can i make it any shorter? (because im using this scene in an animation and i dont want it to take too long.)


(Marty_D) #10

For simple scenes Yafray tends to render at about twice the speed as blender internal on my machine. Again though more tradeoffs. Try Yafray with no global illumination. Very fast.

For the fastest render possible, turn raytracing off and use two shadow mapped spotlights pointing in opposite directions with an angle of about 110 degrees or so. Any wider than that and the shadows tend to be lost altogether. You’ll still be missing light at the edges of the two cones so you want to offset a little to cover the middle ground. Not accurate and no reflections.

Also hardware acceleration helps quite a bit. Build your own from source, or try AN][ARES Intel build . . .


(nico) #11

I made the following candle effect with just one area light:

http://www.nicohagen.com/candle2.jpg

But it’s probably not what you’re after. I wasn’t even good enough for the blender gallery… :slight_smile:


(Marty_D) #12

ooh, ooh, sub surface sampling. Get the Make Human SSSS script and apply to the wax!! (as above?) (very fast)


(Dion Moult) #13

nice scene.

i dont have yafray :frowning:

thanks for the advice i dont think i need much more help now.

you guys are fast replyers.


(nico) #14

No SSS/Yafray in the above picture. A blend texture mapped to emit. Even faster :slight_smile: