Forum: Carrara

Subject: Lighting Question

Parkie opened this issue on Jan 28, 2004 ยท 13 posts

Parkie posted Wed, 28 January 2004 at 2:02 AM

Hi, I have been playing and it ended up with this image (So far). The scene has an atmosphere and one bulb. It is the bulb causing the problem. You will note that there appears to be light shining down the pipe yet the bulb is behind the opening. If I remove the bulb the light disapears. I have checked the texture and it has no transparency. The pipe work was created in the spline editor. The over head insert shows the pipe work and the bulb. Any ideas on what I could be missing so I can get rid of the light in the pipe work and still have the fill light. It is not reflection from the terrain as I have deleted that and still the light is in the pipe. thanks Neil

Nicholas86 posted Wed, 28 January 2004 at 10:31 AM

The pipe is a single piece? I assume you are rendering raytrace and not GI? I did a quick test and didn't have a problem. Not sure what could be causing it, unless your sections of pipe are not sealed together, and light is passing through. Brian

mateo_sancarlos posted Wed, 28 January 2004 at 2:03 PM

Maybe this is another glitch caused by interpolation.

beetle-car posted Wed, 28 January 2004 at 2:24 PM

Possibly your bulb light is set to not cast shadows. Make sure the bulb is set up to cast shadows and see if that gets rid of the light inside the pipe.

rendererer posted Wed, 28 January 2004 at 4:22 PM

Yes, shadows is probably the answer. If the bulb doesn't cast shadows, then it will illuminate any surface that's facing it - even if that surface is inside a pipe.

sfdex posted Thu, 29 January 2004 at 12:35 AM

Are you using C3? C2 has a problem with the soft shadows -- that might well be the problem, too.

Parkie posted Thu, 29 January 2004 at 1:09 AM

I knew someone would have an answer. It was the shadow option on the bulb. I had it turned off. Turning it back on has solved the lighting problem Thanks Beetle-car and Rendererer. Now I wonder why turning off "Casts shadows" will illuminate a surface that is hidden from the light source. Hi sfdex - thanks for the reply. I Am using C3 and the shadows thing fixed the problem. Have fun Neil

ShawnDriscoll posted Thu, 29 January 2004 at 1:17 AM

Carrara calculates lighting first. Shadows are placed during rendering. If shadows are turned off, rendering doesn't include them in the scene.

www.youtube.com/user/ShawnDriscollCG

rendererer posted Thu, 29 January 2004 at 12:20 PM

Parkie, You answered your own question - if a surface is hidden from a light source, that means it's in the shadow of something else. In this case, the inner floor of the pipe was supposed to be in the shadow of inner ceiling of the pipe, and therefore dark. But if you turn off shadows, these natural laws are ignored, and the interior of the pipe is "seen" by the light. It's confusing because it contradicts reality, where there's no such thing as not casting shadows.

GabrielK posted Thu, 29 January 2004 at 3:44 PM

Was this one of the fixes mentioned in the update? I thought I remembered it being listed but I'm not sure. I haven't actually gotten around to installing the update myself.

Parkie posted Fri, 30 January 2004 at 12:37 AM

Thanks, now it is explained, I can see why it happens. Gabrie1k, I'm not sure what was fixed in the update but I have the "03" update installed. So much to learn in a new program. :) have fun Neil

ShawnDriscoll posted Fri, 30 January 2004 at 12:24 PM

It was never a bug. It was an object property that Parkie had disabled. I've done it too, not knowing its meaning at first.

www.youtube.com/user/ShawnDriscollCG

Animoottori posted Mon, 02 February 2004 at 2:49 AM

Turning of shadows speeds up the rendering. If the viewing angle is chosen correctly there is no need for cast shadows. Surfaces that aren't facing the light source aren't illuminated and they seem to be in shadow. For some reasons, bumpmaps appear to react better on non-shadowcasting lights. At least in this test scene.