Tutorial help-Why I can't get shadows?

[lj_1999]

http://www.cgarchitect.com/resources/tutorials/smoke3d/tutorial3.asp

 

I am practicing this tutorial and I got stucked. I am on stetp 3.1 now, why I can't get the soft shadow under the chair? why the omni light outside the window doesn't lit the room? please see attached and give me a hand, Thanks a lot.//Lucy

[Guest nazcaLine]

well...

 

1.your ambient light is 1 in multiplier.that's too much. turn it down. 0.5 would be fine to start.

 

2.the omni in the window, the same. turn it down.oh, it has shadows on, turn it off! the window won't let the light get in. in fact, erase the window by now.

 

3. SHAPE your omnis. you can do it with the non uniform scale, shape them in every axis to fit in the room.

 

4. your direct light, well...put white color to the light...shadow map, not area shadows... put hte light slightly below the ceiling...don't use attenuation...shadow density is in -3, put in -1 to start...

 

good luck.

[a_w]

OMNI01

1. The omni light you used for Step 1 of the tutorial should be moved and scaled so that the Far Attentuation's light brown start ring almost touches your walls, ceiling and floor.

Look in your Left viewport and move Omni01 approx. .4m on the Y-axis so the light brown ring fits within your ceiling and floor. Then go into your Top viewport and scale Omni01 on the X-axis until it looks wide enough to fit your east/west walls. You'll have to move this light along its X-axis too, so it's properly centered to those walls. Do the same for your north/south walls (scale and move the omni light).

FDIRECT01

2. Your free direct light from Step 2 doesn't need Inverse Decay. Set the Decay to None. You also don't need Area Shadows, as Shadow Map will work fine plus shorten your rendertime. Before you change the shadows to Shadow Map, uncheck the "Use Global Settings" option located above the dropdown menu where you choose the shadow type.

Now for the soft shadows, go back to your Shadow Parameters and set the Object Shadow Color to a lighter shade of gray. Your shadows will begin to darken. If the edges of your shadows seem too sharp, open the Shadow Map Params and increase the Sample Range.

OMNI02

3. The omni light outside of your room should have Ray Traced shadows if you want for light to get through the glass of your sliding window.

In the tutorial there is no window object, just a cutout in the wall. For the purpose of following the tutorial, you might want to delete the sliding window object. If not, then make sure before you change the shadow type, you uncheck the "Use Global Settings" option for this light too.

If you do delete the window and decide that you still want this light to cast shadows, the tutorial suggests that you use Shadow Map as the shadow type. When/if you change the shadow type to Shadow Map, be sure to go down into the Shadow Params and set the Object Shadow Color back to black and the Density to 1 (or some other low positive number).

I would also consider increasing your Far Attenuation's start and end size, so more light gets into the room; then going back to the top viewport and scaling the omni light on its X-axis, so the attenuation rings don't touch the east/west walls.

I hope this helps. More than that, I hope it made sense.

a_w

[lj_1999]

Eduardo, A_W, Thanks all of you. With your kinkdly help, I am almost there.

 

By the way, if I want the light comes in from the sliding window, what I should do? I have changed the omni outside the window to ray traced shadow after uncheck the "Use Global Settings" .//Lucy

[a_w]

Now that you've changed your shadows to Ray Traced for OMNI02, the light is coming in through the window. You're not seeing much of its effect because of your low Far Attenuation settings. Turn off Far Attenuation for OMNI02 and you'll definitely see the light -- no pun intended . Raise the Far Attenuation's End amount to 4 or 5m, and you'll see the light plus control how far it goes across your room.

When you're working with lights, it's helpful to turn some lights off so you can see/judge the effect of others. If you temporarily turn OMNI01 off, you'll see the effect that OMNI02 is having and you can make changed accordingly.

Before you go too far with changing OMNI02, please make sure you've made the previously mentioned changes to OMNI01. Otherwise your floor will end up way too bright.

Buona fortuna!

a_w

[lj_1999]

Thanks a lot, a_w

 

I was so busy these days, following your steps, i roughly got what I wanted, but to achieve the effect in the tutorial,

still need a lot to learn....

 

Cheers,

Lucy