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ewoutz
06-28-2007, 04:58 PM
Hello,

I am trying to render a short movie with our new logo in it. I have placed a directional light in front of the logo to create a shadow . this light is not rotated at all.

for some reason the shadows are based on the camera center of interest , As you can see from the render below .

http://www.dpstat.com/index_files/tmp/final_logo_640x480_360.gif

Is there anyway to fix this issue without switching to a spotlight ?

With kind regards

demdike
06-28-2007, 07:08 PM
I hope I got this right...

Assuming you got a plane behind that logo on which the shadow's cast, it of course becomes smaller, the farther it's positioned from the logo.

The first two images show the plane the logo's shadow is cast on far away and closer.
You might wanna try Ambient Occlusion, as shown in the last image, but I don't know if this is what you're after.

ewoutz
06-28-2007, 08:15 PM
demdike,

Thank you for taking the time to reply and also attach some images . I will give the other shadow a try .

still , i dont know why the shadows are rendered like this , i dont see the point , normally a directional light is to simulate the sun for example , why are the shadows based on the position of the camera in stead of the angle of the directional light ?

tfritzsche
06-29-2007, 01:09 PM
ewoutz
if you have the default light on (render globals common tab), this can be the cause. The default light is parented to your camera, so it always points to the camera's center of interest. Turn off the default light and make sure your directional light has shadows turned on. I do not know if you are trying to solve the small floating shadow "issue", but that can be solved many ways depending on what you are looking for: demdike's occlusion shadow, or a "drop shadow", or your floating shadow, etc.. . I am assuming this is the look you want, but having the shadow come from your light.

hope this helps
thomas

demdike
06-29-2007, 02:16 PM
tfritzsche's hint is pretty good, be sure to have the default light checked off.

On the other hand, what kind of shadow are you looking for? A soft contact shadow, surrounding the logo or a hard sunlighttype-kind of shadow?

victor
06-29-2007, 02:59 PM
demdike,
...why are the shadows based on the position of the camera in stead of the angle of the directional light ?You haven't actually given us any reason to think they are based on the camera. You say the light is in front of the logo? And it's not rotated? Is it pointing in the same direction as the camera (towards the logo)?

If so, this image looks right. What are you trying to achieve?

bwheels02
06-29-2007, 06:45 PM
Think about what you are saying... The light and shadow are doing exactly what they are supposed to do in 3D space (persp view). If you want your shadows to line up with the text then use an orthographic view and rotate the light a slight angle. If you still want the 3d text then shift the behind faces in the direction you want. Think like After Effects.

This should give you what you want if I understand what you are looking for. :)

ewoutz
07-01-2007, 12:16 PM
Think about what you are saying... The light and shadow are doing exactly what they are supposed to do in 3D space (persp view). If you want your shadows to line up with the text then use an orthographic view and rotate the light a slight angle. If you still want the 3d text then shift the behind faces in the direction you want. Think like After Effects.

This should give you what you want if I understand what you are looking for. :)


Please see the following example , i expect to get the shadow like on the word "good" , but currently it renders as the word "wrong"


http://www.dpstat.com/index_files/tmp/example1.gif

The default lightning is off and the one directional light that is configured for shadows has an angle of 0 procent , in that case i expect to see no shadows at all if the camera has the same angle aiming at the front of the logo.

This is whole point , i am rendering a short logo animation so at the end the camera should not see any shadows. i could fix this by keyframing the shadow options but i want to know why it can/cannot be done on the normal way.

jeremybirn
07-03-2007, 12:28 AM
The default lightning is off and the one directional light that is configured for shadows has an angle of 0 procent , in that case i expect to see no shadows at all if the camera has the same angle aiming at the front of the logo.

That would be true if the shadow were the same distance from the camera as the text, or if you used an orthagonal instead of a perspective view.

Right now, the shadow is like a same-size copy of the text, directly behind the text. You are viewing the text and its shadow at two different distances in space with a perspective camera, looking through the text to see parts of the (more distant) shadow.

-jeremy

ewoutz
07-03-2007, 12:56 AM
That would be true if the shadow were the same distance from the camera as the text, or if you used an orthagonal instead of a perspective view.

Right now, the shadow is like a same-size copy of the text, directly behind the text. You are viewing the text and its shadow at two different distances in space with a perspective camera, looking through the text to see parts of the (more distant) shadow.

-jeremy

Jeremy and others,

Thank you for all the input in this thread. After all the explanations etc it feels OK to use the shadows as they are now.

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