How to create smooth levels using Inkscape

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Revision as of 21:40, 28 August 2006 by Nadenislamarre (talk | contribs) (GNU/Linux)
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Caution: this software is still in early development stage.

It's more a proof of concept for the time.

Please report bugs on the irc

Required softwares

  • Inkscape (>= 0.43)
  • Python (>= 2.4)
  • Svg2lvl converter and inkscape extension (available in xmoto cvs)
$ cvs -z3 -d:pserver:anonymous@xmoto.cvs.sourceforge.net:/cvsroot/xmoto co -P xmoto/tools/svg2lvl/

Pre-requesites

You have to install the svg2lvl inkscape extension.

GNU/Linux

$ cd the_rep_where_you_ve_done_the_cvs_checkout
$ cd xmoto/tools/svg2lvl
$ mkdir -p ~/.inkscape/extensions/svg2lvl
$ cp svg2lvl.inx ~/.inkscape/extensions
$ cp *.py ~/.inkscape/extensions/svg2lvl

Then, you can launch inkscape.

Windows

Go to the share/extensions/ directory inside your inkscape installation. Create a directory called svg2lvl. Copy the .py files inside that new directory. Then copy the .inx file to share/extensions/

Then, launch inkscape.

Draw the level

Open Inkscape.

Inkscape-empty.png


You're ready to draw your level using Inskcape. See Inskcape howto's from the help menu.

Inskcape-drawn.png

Transform all objects into paths

Inskcape deals with its own shapes like stars, circles, ... so you have to convert them to path of vertex.

Disclaimer: don't put objects properties before transforming them to paths ! Else properties will be lost... Inkscape remove them.


First, select the object, Inskcape-obj.png


Then, Shift+Ctrl+C (or use the menu)

Inskcape-obj2path.png


And you got a path of vertex

Inskcape-path.png

Repeat this process for every inskcape shape (rectangle, circle, star, ...)

Level objects properties

Once your level is drawn, you have to put entities, blocks and sprites properties. Select an object, right click on it, then select 'object properties'.

Inskcape-properties.png


Properties are put inside the 'label' box. They are seperate with a '|'. If no properties are set, then the object is put as a block with default texture. You can also fill the 'id' box, it's useful if you write a lua script for the level, because you got the blocks, zones and entities names to use in your script.

WARNING : properties are case sensitive ! Write them with the exact case as show below.

Block properties

  • background
  • dynamic
  • usetexture=texture_name

Examples

A background block (it's a block in the background and the player can't interact with it) using the Dark Dirt texture:

background|usetexture=DarkDirt

A dynamic block using the default texture:

dynamic

A block using the default texture:

(you have nothing to put in, let it blank (or let what inkscape puts in it))

A block using the Dark Dirt texture:

usetexture=DarkDirt

Entity properties

  • typeid=[PlayerStart|EndOfLevel|Strawberry|Wrecker|ParticleSource|Sprite]
  • size=float_number (the entity colision radius)
  • param_name=param_value available params name are (there's more of them):
    • z (for Sprite)
    • name (for Sprite)
    • style (for every entity)
    • type (for ParticleSource)

For example

A particle source throwing smoke:

typeid=ParticleSource|type=Smoke

A strawberry:

typeid=Strawberry

A tree sprite put under foreground blocks

typeid=Sprite|name=Tree1|z=-1

Player start:

typeid=PlayerStart

End of level:

typeid=EndOfLevel

Zone properties

  • typeid=Zone
The only possible value for a zone
typeid=Zone

Generate level file

Inkscape works with bezier curves, but the converter only use vertex, so you have to smooth objects. Press F2 to select the appropriate tool then select an object. It's not having much vertex. Press Ctrl+A to select every vertex. Then press the '+' button (see screenshot)

Inskcape-add.png


Press the '+' button until you got enough vertex for the object to be smooth.

Inskcape-smooth.png

Repeat that for EVERY objects that have to be smooth blocks in the game (no need to do that for objects which'll be entities or zones)

Feel free to add plenty of vertex because the converter will remove unnecessary vertex. For example, here are the remaining vertex in the sample level:

level in the editor


launch the converter

In order to save your level in the .lvl file format, use the menu File -> Save as... (or use Shift-Ctrl-S) and choose the X-Moto Level file extension, put the level file name then press Save.

Save-as.png

A new window pops, you have to put:

  • level width : the level width in xmoto unit. play with it until you find the right value for your level
  • smoothitude : the higher the value, the smoothest the level. But don't add to much vertex, because xmoto doesn't scale very well with big levels made with thousands of vertex... and became quite slow...
  • lua script  : the absolute path to your lua script (leave blank if your level doesn't have a lua script)
  • level id  : the level id (each level got a unique one)

Then your level file will be save in the place you choose in the Save as... window.

Script-params.png


You can also use the command line.

$ python svg2lvl.py --width=100.0 --smooth=95.0 --lua= --name=myLevelId svgfile > levelfile.lvl

Params are:

  • level width in xmoto unit
  • smooth percent (play with it)
  • absolute path to lua script file (optional)
  • level id
  • absolute path to the svg file

Then, put your lvl generated file into your xmoto Levels directory, and you can play it:

Our level in X-Moto

Files used in this howto