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Djekspek
10-16-2009, 11:07 AM
Hi all, I'm working on a city map that should be some oriental/elfish mixture in a medieval city- layout (not sure if it will work but lets see..). I'm working on the building blocks for houses but have problems getting the shading right. I did some 3d sketch-up meshups to get an idea but I want the shades to reflect structure without having to model every detail in 3d to see the shadow casting). Any help/tips on how to handle this (any fancy Photoshop trick?) is appreciated... ;)

Ascension
10-16-2009, 05:09 PM
No PS tricks that I've ever found. I just draw the shadow out by hand, rotate it, and make a copy of it if it falls upon something else (like a wall or building) and then move it around to represent a faux height and chop off what sticks out.

Tom_Cardin
10-16-2009, 08:31 PM
yeah if you don't want to model everything in 3D then your best bet in photoshop is to draw them in by hand.

When I want a 3D object with a shadow and I don't want to model everything just to have the shadow, as the case of these buildings, I will model the hidden structure with just simple blocks and cylinders. At these kind of scales it creates enough of a realistic shadow that it works for me.
One other thing I do since I don't want to render in the ground for the shadow to appear on because I want to be able to put the item on any kind of ground - In 3DS Max there is a matte/shadow material which I can put on a ground plain. If I render to a file type with alpha channel that will put my object on transparency with a semi transparent shadow. Its the cats meow for work like this.
I have no idea if sketchup has anything similar, but its worth looking into.

Djekspek
10-18-2009, 09:34 PM
Thanks for the tips guys. I tried to export 'alpha shadow' in sketch-up but I don't think it is supported. The 3d layer in PS (I use CS3) also doesn't seem to support shadows. Anyone got experience with CS4? (it claims 'better 3d support' so maybe also shadows...)

At least by making simple models in sketch-up I learn how these nasty shadows behave then copying them in PS as starting point. Hehe, I seems shadowing needs some good ol' fashion handwork :)

Skallagrim
10-26-2009, 09:05 PM
It can make your PSDs a little conveluted, but If you put all 1 story buildings on one layer, all 2 story building on another, etc etc, then you can just use a drop shadows on the buildings, and adjust size and spread to taste till your shadows have the appropriate look...

here's a 30 sec example.

Ascension
10-26-2009, 10:59 PM
The problem with drop shadows is that they overlap if less than 100% opacity and also don't start at building corners. That tends to produce the floating look.

töff
10-26-2009, 11:11 PM
Also, shadows should be sharper near the objects, and fuzzier further away.

But I don't know how to achieve that, except manually.

RobA
10-27-2009, 03:40 PM
Also, shadows should be sharper near the objects, and fuzzier further away.

But I don't know how to achieve that, except manually.

There are focus blur pugins for photoshop and gimp that use a focal depth map... These works, but building the proper map is almost more effort than the actual blurring ;)

-Rob A>

Major LEE
12-12-2009, 05:26 AM
Hep perhaps I find a solution to the problem
control clic on the building layer to load selection
creat new layer under the building one
selct it and fill selection with black
move this layer down and right (about 5 pixel depending on the scale of the map)
copy this layer and move again
repeat the previus step 5 time or more as you want
merge all this shadow layers
apply a gaussian blur to the merged layer
set its tranparency to 50%
http://maltarit.free.fr/ForumLinked2009/shadows_exemple.png

Ascension
12-12-2009, 04:12 PM
Yep, that's the standard method but most folks just starting out find drop shadows easier despite its flaws.

Boethius61
12-14-2009, 07:10 PM
Hmmm . . . Major LEE could you not shorten that up a bit. Instead of copy, move, copy, move, copy, move . . . until the shadow is big enough then merge them all; you can do it all in one step with the brush. (At least in GIMP you can.)

1) start as you start - a new layer underneath with the building shapes all filled in black.
2) ctrl-a, (select all), ctrl-c - (copy). Now the layer is in the clipboard.
3) Using your brush with the clipboard selected as your brush (it will be the first brush in the list) line up the brush with the image click then move in the direction you want your shadow and shift click.
EDIT: 4) blur.

GIMP will use the black houses as a brush and draw in a straight line from the click (under the houses) to the shift click.

I got this in about 30 seconds.
EDIT: I went back and tried it again timing it and doing this was faster than waiting for the drop shadow to run.
19498

Boethius61
12-14-2009, 07:14 PM
here it is with the blur.
19499

Ascension
12-14-2009, 08:25 PM
Something similar can be done in PS as well but the reason for the copy-move-repeat-merge layers is to control the length of the shadow. Just eyeballing and brushing it in can produce some shadows longer than others. Plus with PS you can turn the whole thing into an action that does it all for you with just a click. The other reason is that in PS we often use layer styles and if we put a black outer stroke on the house then the shadow comes out the size of the shape itself without factoring in the stroke, thus the shadow comes out smaller and doesn't line up properly. Lots of ways to do the same thing I guess so thanks for adding this info. :)

Boethius61
12-14-2009, 10:06 PM
Cool. I like things that can automate repetitive stuff.

All my shadows would be the same length, though, I used one house in my example but in a real map I would do them all at once because I selected the whole buildings layer for the clipboard.

As an aside, clipboard to brush, pencil, airbrush is one of my favorite tools. A thousand different uses :)

Ascension
12-14-2009, 10:47 PM
Maybe RobA and his Gimp wizardry can write a script for copy layer, move it down 1 pixel, move it over 1 pixel, repeat 9 times, merge layers and that would function the same way.

RobA
12-15-2009, 05:32 PM
I usually use the motion blur that gimp provides. Threshold transparency (alpha channel) then gauss blur slightly:
19534

The script in gimp would be trivial, however.

@Boethius61 Also, there is a limit in gimp that clipboard brushes are a max of 512x512, this only works when the area you want to work on is smaller than that.

-Rob A>