LFS Editor/Modeller

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Live for Speed Modeller



This is not intended as a complete manual. It's more like an incomplete FAQ and reference document.

To learn the basics of the LFS modeller, please watch the mods tutorial videos.



Background images

You can load background images to help with modelling.

  • Save a square png image (probably 1024x1024 or 2048x2048) in your data\bkg folder
  • Go into a 2D view (R/F/V etc)
  • At the bottom right click "load bkg" to load your image
  • Click "adjust" then use the mouse to adjust the position and size
  • After clicking "adjust" you can also click "bkg scale" to type in the scale
  • Repeat the steps above for any of the other main 2D views
  • Then click "save scm" which saves the whole scheme of adjusted backgrounds so you can easily load it next time
  • The "use opposite" option: for example on the left side it will use the right side image and position, automatically flipped



Customisable colours

You can set colours to be adjustable, when a user enters the garage screen and clicks "New colours".

This is done by giving some of the mappings a special name. Each mapping has a colour, but sometimes you want several mappings to have the same colour. For example the top and side mappings of a car. You can define a "Main" colour and "Copied" colours. So for example you could set top mapping to be a Main colour, then assign the side, front and rear mappings to be Copied colours of the top. Main colours are identified by the letter M followed by a number, while copied colours are identified by the letter C followed by the same number.

Taking the example above, you could name your mappings (colours) like this: 

    M1_top
    C1_side
    C1_front
    C1_rear

As soon as you set the names this way, you will notice the C1 colours aren't adjustable in the modeller. You can adjust the M1 colour and all the C1 colours will take the same value. Also this colour is now adjustable by the user, in the settings block. You can see that in the vehicle editor in the Colours section.

You can allow more than one customisable colour group, as seen on some of the LFS cars. This is done by creating M2 / C2 colours, up to a maximum of 4 customisable colours.

Note 1: You can use copied colours without them being adjustable by users. Use higher values than 4. E.g. M5_original and C5_copy.

Note 2: Customisable colours are also available for subobjects. To use this feature, select the subobject and switch on "use custom colours"

Advanced: You can also create a darker copy of the main colour, by using the prefix 'D' for dark or 'E' for extra dark. This can be useful to fake reduced ambient lighting if you are adding surfaces in a place where there should be less light. For example: 

    M1_main - the user can set this colour
    C1_copy - direct copy of M1_main
    D1_dark - darker copy of M1_main
    E1_extra - extra dark copy of M1_main



Modeller tips

  • The list of colours at the bottom left in 'tri' mode is a different view of the list of mappings in 'map' mode.
  • When you select a triangle, its colour is selected in the bottom left list. If the list is long, click "cols : X" to bring the selected colour onto screen.
  • In 'subob' mode you can select a subobject with CTRL + click while pointing at one of its surfaces.
  • In 'tri' mode, CTRL + click adds or removes triangles from the selection. ALT + click starts a new selection (one triangle).
  • In the special view modes (like groups or mappings) the group select feature (CTRL + SHIFT + click) does a flood select within the group.
  • Press SHIFT+F to temporarily hide the editor buttons.
  • To reduce clutter, use 'hide selected' to temporarily hide points and triangles, then 'unhide all' to show the again.



Light colours: headlights, indicators, etc.

All light mappings have a name with prefix "l_"

The cutouts for all light mappings must share a single texture page.

The special names for light mappings are: 

    l_brk - brake (main mapping of brake light)
    l_sbrk - side brake (e.g. side of a curved brake light)
    l_tbrk - top brake (e.g. top of a curved brake light)
    l_cbrk - centre brake (e.g. brake light in rear window)
    l_head - headlight (main headlights)
    l_side - side light (smaller lights near headlights)
    l_tail - tail light (red rear lights)
    l_stail - side tail light (e.g. side of a curved tail light)
    l_ttail - top tail light (e.g. top of a curved tail light)
    l_rind - rear indicator
    l_find - front indicator
    l_rsind - rear side indicator
    l_fsind - front side indicator
    l_rfog - rear fog light
    l_ffog - front fog light
    l_rev - reversing light



Level of detail (LOD) and Shadow / Physics / Collision meshes

When you first start work on a mod, you can test it in LFS with only a single level of detail. That is the main graphical LOD, known as LOD1. But your mod cannot be uploaded to the website like that. It needs at least a physics or collision mesh, and finished mods should usually have a shadow mesh too.

There are two possible LOD choices for a mod you upload to the website.

Work in progress / test mod - 2 levels of detail

LOD1: The main graphical LOD
LOD2: The low resolution physics / collision mesh

In this case, the collision mesh doubles as the shadow casting mesh. For most models this approximation is too crude, because the collision mesh is very limited in the number of points and triangles. But it's fine for early testing.

Completed mods usually have 3 levels of detail

LOD1: The main graphical LOD
LOD2: The shadow and distance view mesh
LOD3: The low resolution physics / collision mesh

In this case, LOD2 is drawn when the mod is in the middle distance. This saves the graphics card doing a lot of work drawing detail that you can't see and helps with frame rate. This LOD should be a good representation of the shape of your mod, so it looks good in the distance, and casts a good looking shadow. LOD3 is only used as a visual representation when the mod is very far away. Its main purpose is for collisions with other vehicles or when your mod hits a wall or rolls over.

How to add an automatically created physics / collision mesh

  • In the modeller, click the + (plus) button to the right of lod1 (near the top left) to add a new LOD
  • Now select lod2 or lod3 (the newly created, empty LOD)
  • Click "auto-create collision mesh"

The automatically created collision mesh is created based on the size of the existing LOD1 (high detail) mesh. This should provide basic collision physics but you will probably want to improve the shape to make it a better match for your vehicle.



Draw order of materials

You can see a material list in the vehicle editor "Class/Textures" tab. That should represent the draw order of the materials.

To actually change the draw order of the materials, you adjust the draw order of the cutouts in the modeller. The draw order is assigned by the order the materials are first encountered in the cutout list. The material's index is the number on the right of the 'material' column in the list of cutouts.

The idea is to make sure the material for the steel frame appears in the cutout list before the material for the cloth cover. For example if you selected a material with material index '2' and move it to the top of the list, then on reaching the top, it should acquire material index '1'. What was material 1 will become material 2.



Draw order of individual triangles

Within materials, triangles are drawn in the order they appear in the internal list of triangles. LFS doesn't give you direct control over this list, but you can improve the draw order by clicking "magic triangle sort". This function tries to adjust the draw order so that further away triangles are likely to be drawn first. This may be better than randomly ordered triangles, and may help with "Z fight" problems if the nearby surfaces share a material so you can't manually correct the draw order by ordering the materials.



Creating a SKIN texture

A skin is a special texture designed to cover the paintwork of your vehicle so that other people can create their own custom paint jobs. The idea is to uniquely cover the whole paint surface of the vehicle without any part of the texture being used more than once. As a mod creator you may take on the task of creating a default skin that people can modify to use when driving your mod. Here are a few tips for designing skins.

A skin must be created as 1024 or 2048 square image. To load it into LFS it must be saved as a JPG in your data\skins folder, with a name like ABC123_NAME.jpg where ABC123 is the Skin ID of your mod and NAME is a name for the texture (usually DEFAULT for a plain texture).

The artists who create custom skins prefer everything lined up as well as possible, so try to use the options "link with SIDE" / "link with FRONT" / "link with BACK" / "link with TOP" for the main mappings, so your mappings have the correct width.

You can type in the height of the mapping, to make sure front, back, side mappings have the same height. You can also type in the right, front, up values.

Try to keep the pixels of your mappings fairly square (cutout has a similar aspect ratio to the mapping). The squarer they are, the easier for your skin artists.

TIP: Not *everything* needs to be skinned from a proper direction. E.g. skin artists may be quite happy with a single mapping for a wing mirror, probably from the front, that goes right through the object (so the side and top surfaces are not individually mapped). Smaller mappings don't 'link' with any other mapping.

Skins on models with complex shapes may have the added complication of overlapped areas. So you should plan this in advance, where you want the MAIN top, front, side, back mappings and allow enough space for the overlapped areas to be mapped separately. You may wish to follow the general idea of one of our default skins, and change it to suit your needs.

You may find the "copy screen shot" function useful. It takes the correct size screenshot of the mesh for the selected mapping, and copies that to the clipboard so you can paste it into your work-in-progress skin in your 2D graphics software. Before using this function, use a white (or light grey) car colour, and move the lighting UP by using CTRL + left



Importing from other 3D modelling software

You can import the points and triangles from another 3D program by exporting an OBJ file and loading it into LFS from the data\obj folder. Texture mappings and materials are not imported.

How to export from Blender:

Scale

LFS uses metres for units. If you use another unit, please export using an appropriate scale.

Position

Your model should be approximately centred over the origin and ideally the body should sit on the ground (without the correct ride height)

Backface culling

Live for Speed uses single sided triangles. While modelling in blender and before exporting, make sure you look at your model with back face culling enabled so you can be sure the surfaces are facing the right way.

Export Settings - Export OBJ file

Transform:
- Y forward / Z up (so the model is oriented correctly in LFS)

Geometry:
- Write normals (so LFS can work out smoothing groups)
- Triangulate faces (as LFS geometry is based on triangles)


Extrude and Lathe functions

To use the extrude or lathe functions, first you select a series of points in order to create a cross section that you will either extrude linearly (extrude) or rotate around a point (lathe). You can see the cross section by enabling the 'trace' option in point mode, then selecting points in the correct order. It can sometimes be confusing which order to select the points, and then choose 'inside' or 'outside' to get the desired effect.

Extrusion

  • Put your viewpoint on the side so that you will pull the extrusion towards you
  • Select the trace points in anti-clockwise direction as seen from that point
  • Create extrusion by clicking 'extrude' (and select outside, inside, etc.)
  • Pull the points towards you

Then you should find that your inside / outside request is respected.

Lathe

  • Put your view on the side where the lathe operation will initially head towards (at the start of the curve)
  • Select the trace points in anti-clockwise direction as seen from that point
  • Rotation will take place around the last point you select (which may or may not be included as part of the cross-section)
  • Go to 2D view and create lathe object by clicking 'lathe' (and select outside, inside, etc.)



Moving parts of a model to a different model

This is done by saving a subobject from one mesh and loading that subobject into another mesh. In 'subob' mode, with a subobject selected, you can see light green 'load' and 'save' buttons beside the word 'subobject' at the bottom left. These will load and save subobjects with the extension '.sre' in the folder data\3dob.

But what if the parts you want to move are not part of a subobject? In this case you can use the 'break off' and 'merge' functions.

  • Create a new empty subobject
  • Select the triangles in the main object that you want to move to another object
  • Click the "break off" button
  • The triangles (and mappings) are moved into the new subobject
  • Save the subobject
  • Load the mesh where you want to add the subobject
  • Add a new, empty subobject to that mesh
  • Load the saved subobject into your new empty subobject and move it to the right position
  • Optionally, click "merge into main" to merge the new subobject into the main object


Troubleshooting

Invalid texture [texture name] - Colour type RGBA but A is not required

This means that you have exported a texture that contains an alpha channel (32-bit) but you are trying to load it as a non-alpha texture (24-bit). If you do want to include an alpha channel, the texture name must end with the suffix _ALP.

  • 24-bit (RGB) textures should be named like this: TextureName.png
  • 32-bit (RGB+A) textures should be named like this: TextureName_ALP.png

NOTE: In the current public version of LFS, the alpha channel (just like the R,G.B channels, it is a number on each pixel from 0 to 255) is only used for transparency (actually 'opacity' - higher alpha means less transparent). In fact alpha channels can be used for various purposes, for example in the development version of LFS it can be used to specify the reflectivity of each point on a texture page.



ERROR in object X: N points with a bad normal

This usually means that some triangles, within a single smoothing group, meet at a point such that LFS does not know which direction that point should face. Most commonly, this can happen if a triangle is built in one direction, and another triangle is built on the same points, in the opposite direction. The point directions (known as 'normals' add up to zero, so LFS cannot decide where the normal should really point). Maybe the triangles were built this way by mistake, or maybe you intend to create a double-sided surface. If you do want a double sided surface, the triangles on one side should be in a different smoothing group from the triangles facing in the opposite direction and that will solve the problem.

The trouble is, you may not know exactly where the problem is when you see this message. It may also come up if you import a mesh (as an OBJ file) from some other 3D modelling softrware. Have a look around your model, for vertical red lines. LFS tries to display a red line where any of these bad normals are found. At the bottom of the red line you should find the offending vertex. The line is bright red where it is exposed, and a darker red where it is behind some surfaces of the model.



Mod looks shiny in the editor but matt in game

If you only have a single LOD (level of detail) the environment map is not shown because LFS thinks it is drawing the the physics LOD. That is because the collision mesh is defined by the lowest level of detail (LOD with the highest number).

To solve this, you can easily add an automatically created collision mesh (also known as physics LOD). How to do this is described in the 'Level of detail' section above.



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