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How to make a shadow in front of the object, not behind

Sep 10, 2014, 08:24
Post: #1
How to make a shadow in front of the object, not behind
Hello y'all Smile

The photo attached shows (blue) two shadows cast by the bike from two different angles: 161 and 23. Setting the shadow angle between the two values would place the shadow somewhere in between the two existing ones.
Okay... but neither of these correspond with the direction of the sunlight, instead the shadow should be cast in front of the bike (marked in red).
How can this be done? (it's not the matter o the angle, but of the direction of the shadow)
   
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Sep 10, 2014, 09:44
Post: #2
RE: How to make a shadow in front of the object, not behind
Thanks man! ...so basically it's a "no can do"
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Sep 10, 2014, 10:40 (This post was last modified: Sep 10, 2014 10:50 by rich2005.)
Post: #3
RE: How to make a shadow in front of the object, not behind
Practise making a shadow manually.
Most often used with text but for your bicycle layer.

duplicate the layer
desaturate the layer
flip the layer vertically
resize vertically to squash
rotate and move to fit the original
shear to match the direction of the light.
apply a strong gausion blur
Adjust the opacity to suit.

Looks more complicated than it is.
but as Ofnuts pointed out because of the orientation of the bicycle the shadow tends to be long and thin.

as this http://i.imgur.com/clYvdcY.jpg

Instead of giving up why not think of ways around the problem. A simple way would be to flip the bicycle layer horizontally so it presents broadside to the sun.
then the procedure to make a shadow is the same as above.
http://i.imgur.com/ZLQMTPQ.jpg

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Sep 10, 2014, 11:54 (This post was last modified: Sep 10, 2014 11:58 by ianp5a.)
Post: #4
RE: How to make a shadow in front of the object, not behind
I would do it with manual painting on a new layer.
Either imagine what the shape would look like. Or:
Take a real bike out in the sun and position it in the same way, and take a photo. (Use moonlight if you are a vampire)
It is probably quicker to copy the shadow from the photo by eye, and not try and use the actual photo.
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Sep 18, 2014, 11:56
Post: #5
RE: How to make a shadow in front of the object, not behind
Hey Folks, thanks for the advice, but what I did was just to:

- cast a perspective shadow in the correct direction, right - in this instance (adjusting the opacity and the blur radius to my fancy)
- use the combination of: Perspective (most of all), Move, Rotate and Scale tools to place the cast shadow in the correct place

it worked pretty well Wink
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Sep 20, 2014, 01:36
Post: #6
RE: How to make a shadow in front of the object, not behind
(Sep 18, 2014 12:43)ofnuts Wrote:  
(Sep 18, 2014 11:56)adamail Wrote:  Hey Folks, thanks for the advice, but what I did was just to:

- cast a perspective shadow in the correct direction, right - in this instance (adjusting the opacity and the blur radius to my fancy)
- use the combination of: Perspective (most of all), Move, Rotate and Scale tools to place the cast shadow in the correct place

it worked pretty well Wink

... it looks pretty well until someone looks closely at the shadow Smile

Well in this case, don't look too close xD

I found an interesting way to get maybe an accurate direction of the shadow.
On the left picture, I first flipped the shadow vertically, then horizontally, then rotated it to match the angle of the wheels.

- with rotate tool(Rotate), if you drag the middle cross-hair , you can pivot the rotation to wherever point you put it.
- First, use the move tool to line up the back wheel shadow with the bike's back wheel.
- Then, with the rotate tool, drag the pivot cross-hair to the back wheel, and then rotate the shadow so the front wheel is under the bike's front wheel

Last, I perspective warped (Perspective) the shadow *BUT HERE'S THE COOL PART!*
I made a parallelogram, parallel to the angle of the sun rays & ground angle.

[Image: 6cPmdSHl.jpg]
*Click for important perspective shape details


This may work for all the angles you can see on a sundial
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