Difference between revisions of "Cutaway panels in GIMP"

From PioneerWiki
Jump to: navigation, search
m (Drawing shadows)
m
Line 17: Line 17:
  
  
Use 'Fuzzy select' (Shift + left click to add to selection) to select a group of components that you imagine should be of the same height. In the 'Paths' dialogue, select 'Selection to Path'. Repeat, until you have a path for each height group.
+
Use 'Fuzzy select' (Shift + left click to add to selection) to select a group of components that you imagine should be of the same height. In the 'Paths' dialogue, select 'Selection to path'. Repeat, until you have a path for each height group.
  
  
 
== Drawing shadows ==
 
== Drawing shadows ==
  
First, set the parameters for the 'Airbrush' tool so it looks like a shadow, something like black at 60 - 80% opacity, with a round brush set at a little over double the size you really want. Create and activate a new transparent layer. Select a height group's path, and choose 'Path to Selection'. Select a path for a higher up height group, and choose 'Paint along the path' -> 'Stroke with a paint tool'. Choose 'Airbrush' and hit 'Stroke'.
+
First, set the parameters for the 'Airbrush' tool so it looks like a shadow, something like black at 60 - 80% opacity, with a round brush set at a little over double the size you really want. Create and activate a new transparent layer. Select a height group's path, and choose 'Path to selection'. Select a path for a higher up height group, and choose 'Paint along the path' -> 'Stroke with a paint tool'. Choose 'Airbrush' and hit 'Stroke'.
  
 
As you can see, you've projected a shadow from one height group onto another. By adjusting opacity and width for different combinations, you can create a consistent, and reasonably convincing illusion of depth.
 
As you can see, you've projected a shadow from one height group onto another. By adjusting opacity and width for different combinations, you can create a consistent, and reasonably convincing illusion of depth.
Line 32: Line 32:
 
=== Angled surfaces ===
 
=== Angled surfaces ===
  
If you have a surface which is supposed to be angled, you'll need to create a separate layer for it's shadow. Draw a shadow on it using the same method. Right click on the layer in the 'Layers' dialogue, and choose 'Add Layer Mask' -> 'White'. Now draw a dark to light gradient across the surface, the dark part being the area of shadow you want to remove. Right click on the layer and choose 'Show Layer Mask' to view it. Play around with the gradient's colours, position, and offset, and the layer's opacity, till it looks right.
+
If you have a surface which is supposed to be angled, you'll need to create a separate layer for it's shadow. Draw a shadow on it using the same method. Right click on the layer in the 'Layers' dialogue, and choose 'Add Layer Mask' -> 'White'. Now draw a dark to light gradient across the surface, the dark part being the area of shadow you want to fade. Right click on the layer and choose 'Show Layer Mask' to view it. Play around with the gradient's intensity, position, and offset, and the layer's opacity, till it looks right.
  
  

Revision as of 14:00, 15 March 2013

The outline

Draw your outline in another program - GIMP isn't really suited to this. LibreCAD is pretty good, Inkscape would also work. You're going to use it for selections, so make sure all the lines meet up. Leave a border - you can trim it off later if you don't want to include it in the final texture.


Cutaway.panels.cad.png


Import the file into GIMP. Duplicate the layer, and erase any stray lines that shouldn't be visible (useful to keep an intact backup, so you can still select the full shape of any component easily).

Once done, if you have a black or white background, turn it transparent with 'Colours' -> 'Colour to alpha'. You might want to create a blank black or white layer to put behind your outline as an editing aid to make the lines stand out.

Defining paths

Cutaway.panels.paths.png


Use 'Fuzzy select' (Shift + left click to add to selection) to select a group of components that you imagine should be of the same height. In the 'Paths' dialogue, select 'Selection to path'. Repeat, until you have a path for each height group.


Drawing shadows

First, set the parameters for the 'Airbrush' tool so it looks like a shadow, something like black at 60 - 80% opacity, with a round brush set at a little over double the size you really want. Create and activate a new transparent layer. Select a height group's path, and choose 'Path to selection'. Select a path for a higher up height group, and choose 'Paint along the path' -> 'Stroke with a paint tool'. Choose 'Airbrush' and hit 'Stroke'.

As you can see, you've projected a shadow from one height group onto another. By adjusting opacity and width for different combinations, you can create a consistent, and reasonably convincing illusion of depth.


Cutaway.panels.shadows.png


Angled surfaces

If you have a surface which is supposed to be angled, you'll need to create a separate layer for it's shadow. Draw a shadow on it using the same method. Right click on the layer in the 'Layers' dialogue, and choose 'Add Layer Mask' -> 'White'. Now draw a dark to light gradient across the surface, the dark part being the area of shadow you want to fade. Right click on the layer and choose 'Show Layer Mask' to view it. Play around with the gradient's intensity, position, and offset, and the layer's opacity, till it looks right.


Cutaway.panels.mask.png

Textures

Add texture layers beneath your shadows, and you're done.


Cutaway.panels.texture.png