Modding a house in Second Life: tips and pointers

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I recently wrote about my purchase of the CONVAIR Edelweiss Chalet and work on modifying it for use on our main island home (see: A little Edelweiss in Second Life).  The article prompted a request from BarbarA for me to go into more detail about how I go about such work – and it’s not the first time I’ve received such a request.

Truth is, and for a variety of reasons (e.g. how any particular house is put together, what someone might want to do with a house, etc.), providing a step-by-step guide to modding a house isn’t really practical. So instead, I’ve tried to provide a set of more general notes focused on how I go about things.

Basic Skills

Obviously, any modding requires some basic skills:

  • An understanding of the core Build functions (e.g. creating prims; moving / rotating / resizing objects; using Shift-select; linking (CTRL-L) and unlinking (CTRL-SHIT-L) objects / object parts; use of the Show Transparent Prims toggle (CRTL-ALT-T).
  • Knowledge of texturing: how to select object faces, apply textures, scale and (possibly)  rotate them; how to use Local Textures to “test fit” textures you may wish to upload from your computer & use; and a basic appreciation of basic texture memory use. Note that “seamless” textures are generally best for buildings.
  • A basic understanding of the permissions system, particularly the Modify and Copy permissions (the former is vital to any form of modification, since without it you won’t be able to alter a building so easily; latter a nice-to-have).

An article like this isn’t really the place to go into any of the above in particular depth, so I refer those who need to learn more about editing and building in SL, I’m including some links to resources at the end.

My General Approach

I tend to approach modding any building as a 3-step process:

  1. Determine what is to be done. For example: will the work require combining parts of different buildings? Will it involve integrating items from other creators? Will it require inclusion of purpose-made new prim elements (e.g. walls, floors, etc.)?
  2. Visit a copy of the building in-world (e.g. a copy displayed at an in-world store or found in a public region) before any purchase and:
    • Confirm it has the required permissions (generally Copy and Modify).
    • Examine the use of textures to determine if they might need replacing / make require replacing as a result of my changes (e.g. because some surfaces have shadows or lighting effects “baked” into a texture.
    • Check how the building has been put together, and whether the desired changes can easily be made (e.g. by removing parts), or whether there might be complications / whether you may have to include “replacement” prim parts yourself.
    • Look at the general structure of the building and whether simple structural changes can be made to  improve LI.
  3. Revise plans accordingly after (2.), and if the decision is made to go ahead, break the work down into logical steps and complete each in turn.

Checking the Suitability of a Building for Modding

Checking Textures

There are a couple of reasons why textures might need to be replaced:

  • They don’t meet the desired aesthetics.
  • They include “baked” details that may not be wanted.

In the case of the latter, some baked details may be easy to spot – as per the image below left, other may be harder to identify, such as with the image below right, and may not be revealed until you actually start physically altering the build, should you go ahead. However, in both cases, it’s worth checking the faces (surfaces) of a building that you might want / need to re-texture.

Some builders bake details into their textures, such as the light “cast” by windows (l); or shadows which can be left behind when an element of the building is moved or removed, as with the railings (r). So careful checking of a building may help determine where / if textures may be replaced.

Carrying out such checks is pretty straightforward:

  • Visit a copy of the building in-world and right-click on it and select Edit from the menu.
  • In the Edit floater, do two things:
    • Click on the Edit Linked selection box to make sure it is ticked (enabled).
    • Click on the Select Face radio button to enable it as well.
  • Finally, left-click on the surface in the building you would like to re-texture to display the texturing cross-hairs.
Identifying and checking surfaces for re-texturing it. Use the Edit Linked and Select face options in the Edit / build floater to identify the extend of a given face, shown by the cross-hairs (arrowed).

Note that some builders incorporate transparent prims in their builds (e.g. in walls and floors). Such prims can get in the way of checking surfaces, so you must keep an eye out for them. There are two ways to do this:

  • By pressing CTRL-ALT-T: this will highlight all transparent surfaces in red. If a part of the red is highlighted, then you have likely selected a face of the transparent prim.
  • With the surface selected, click on the Texture tab in the Edit floater. If the Transparency % spinner is set to 100, you have selected the face of a transparent prim.

Should you find you’re actually selecting a transparent prim face instead of the surface you want, I’m afraid there is no easy solution except manoeuvring your camera in as close as possible to the surface you want, and then trying to select it. To assist with this, go to the Advanced menu (use CTRL-SHIT-ALT-D to display the Advanced menu if not already enabled) and make sure Disable Camera Constraints is checked (click it if not).

With the required surface selected, check around it carefully for any of the following:

  • If the cross-hairs / highlighting on a wall / floor / ceiling extend into other rooms beyond the one you’re checking (e.g. a neighbouring wall / floor).
  • Whether the highlighting extends to other features within the surface you’ve selected (e.g. if you’re checking a wall with a window frame, is the frame also highlighted, or if you are checking a door, is the handle and other furniture also highlighted?).
  • Do any other parts of the house you might not expect to be highlighted appear to be so?
Always check around surfaces you might want to re-texture to see how other surfaces might be affected. Left: the texture cross hairs extend beyond a doorway into the next room, indicating they share a single wall face. Centre: selecting a single roof beam (arrowed) all selects those “in front” and “behind” it, indicating they are all a single texture face. Right: selecting the paintwork of the door (right side arrow) also highlights the door handle (left side arrow), indicating they are the same face and any texture applied to the door will also cover the door handle.  

If the answer to any of these questions is “yes”, then the items that are highlighted will also be affected by any texture you apply. This doesn’t mean you cannot necessarily go ahead with your ideas, just that you may revise what your re-texture or how you go about your alterations (e.g. might your problem be overcome by adding a prim and texturing that?).

Checking the Structure

Typically when examining a house I may want to modify, I generally look for the following:

  • Have transparent prims been used to provide “solidity” to mesh walls and floors that do not have physics applied? If so, are they in a location where the building be simplified if they and the mesh they assist were replaced with prims?
    • Example: the CONVAIR Edelweiss has a rectangular floor made up of four elements: two textured mesh parts and two transparent prims to give it solidity. By removing the mesh, then making the prims opaque and re-texturing them, I reduced the LI on the building by 2.
  • Are there any parts that might not fit the intended location for the house, and so can be removed?
      • Example: the CONVAIR Edelweiss featured external steps to link it with the ground. As I knew these would not be needed, I checked to ensure they could be removed with relative ease.
  • Are the any significant barriers to what I want to achieve, or any elements I may have to work around?
  • Can I add to a house through the use of “sub-assemblies” and without excessive LI?
    • Example: Linden Homes are No Modify. However, when I was using the Houseboat types, which all have large single room spaces, I constructed interior walls and floors with linked prims to create my desired interior design.

Checking how parts of a building might be modified is also fairly straightforward:

  • Visit a copy of the building in-world and right-click on it and select Edit from the menu.
  • Click on the Edit Linked selection box to make sure it is ticked (enabled).
  • Left-click on the part you may wish to remove. It should be outlined in blue.

Important: if the selected element is outlined in yellow, it is the “root” of the building. When it comes to actually making your modifications, unless you are very confident with using the building tools, this is the one part of a building that you may not want to alter / remove.

What you’re looking for here are three things:

  • Does the blue outline cove all of the part of the house you wish to remove, or are some parts left without any highlighting? If the latter is the case, press and hold the SHIFT key and then left click on the remaining parts so they are also outlined (see the image below).
When checking to see how parts of a building might be modified using the Edit menu, always check whether the entire section you wish to remove is highlighted (l); or whether just a part of it – such as the railings in a set of steps, but not the steps (centre). In the case of the latter, SHIFT-left-click can be used to to select the remaining part(s), which will also be outlined in blue (right).
  • Are any elements of the building you do not necessarily wish to remove / alter also highlighted? This can be a little tricky, and mesh parts can be quite complex, so you need to check carefully.
    • Example: in the CONVAIR Edelweiss build there are two upper floor levels that appear separate, as they are at opposite ends of the house; however, they are both actually part of the same mesh, as shown in the image below.
When thinking of altering a building be removing sections, always check to see how the pieces might actually have been made, to avoid unexpected results when making alterations. In  this image of the CONVAIR Edelweiss Chalet, selecting the floor in the foreground (note the blue highlight at its edge shown by the yellow arrow), also selects the floor on the upper level at the other end of the house (indicated by the blue arrows and highlighting).
  • Whether the build includes transparent prims, and how these might influence the changes you want to make.

Only when you’ve surveyed your chosen house and determined whether your ideas for it are feasible (with or without adjustments resulting for your survey), should you go ahead and make your purchase.

General Notes on Modding


  • Textures can be obtained from a variety on in-world / marketplace stores and from various on-line resources.
  • Always try to use “seamless” textures – a maximum resolution of 512×512 pixels should be adequate for most tasks.
  • For better optimisation when replacing textures, try to re-use textures where you can, such as with walls and floors, across window frames, etc.
  • Try to use normal and specular maps only where absolutely needed, as these can also add to the texture overhead placed on the viewer / computer.
  • When working with textures from on-line resources, remember you can use the Local Textures capability to “test fit” them.

This diagram below provides a general overview of the texturing options you’re most likely to use.

Textures can be applied by dragging them from inventory and dropping them into the texture swatch (1), or by clicking on the texture swatch to open the Picker and selecting them from there (2). The Texture swatch also provides you with access to the Local Textures capability (circled). Textures can be tinted via the colour swatch (3.), and scaled for greater clarity (4.) or rotated (5.) to achieve a desired result.

Making Physical Alterations

  • Try to keep things relatively simple.  Don’t assume you’re going to necessarily be able to move / replace entire walls, etc.
  • When unlinking parts of a building (e.g. for removal), always make sure Edit Linked is selected before you start.
    • Should you accidentally unlink (CTRL-SHIFT-L) an entire build don’t panic! Providing you keep the entire selection highlighted, press CTRL-L to re-link it again.
  • If you are adding new elements to a building (e.g. other items you have purchased and wish to make a part of the structure) make sure:
    • If they are items you have purchased, that they share the same permissions as the house to avoid unnecessary confusion.
    • If they are prim items:
      • Keep your links to basic prims; cubes and cylinders with simple cuts.,
      • Avoid linking them if they are made with complex cuts (e.g. twists, slices, hollows) and/or are themselves a complex form (e.g. Torii, rings), as doing so could increase the overall LI of the house.
    • Remember that adding basic prims to a mesh structure might reduce the overall Land Impact than would be the case if they are kept as individual pieces (e.g. a 90 LI house and a single additional “wall” prim you create would separately be 91 LI. However, if the “wall” is linked to the house, the LI may remain as 90). For more on this see Using Convex Hull To Lower Land Impact by Ciaran Laval.
    • As a general rule, keep your links simple: pictures on walls, rugs, and the like. Avoid major items of furniture or heavily scripted items, as these may lead to complications / unexpected LI increases.
    • Don’t go “link crazy” and try to link absolutely everything into a single entity; unhappiness will inevitably result.
  • Remember Some buildings use transparent prims – you can check for their presence using CTRL-ALT-T.
    • As noted above, some of these might be parts you can unlink and remove. However, be aware that most are there because the underlying mesh is without physics, so if the transparent prims are removed, you may fall through floors or be able to walk through walls.
      • It is generally best not to remove transparent prims and convert the mesh physics type where this is the case, unless you know exactly what you’re done, as doing so can lead to other problems (e.g. an inability to walk through doorways).
  • Try to tackle the work logically and slowly;  break your modifications down into stages and tackle them in turn.
    • My general order of work is to make the physical changes first, then the texturing.
  • Assuming the building you have is Copy, remember you can use Take Copy to “save” a version of it to inventory as you complete modding parts of it. That way, you always have a “back-up” you can re-use should things go wrong at any point.

In Conclusion

This is not intended as a comprehensive guide; if you’re not familiar with building in SL I would not recommend trying to use the ideas here as a means to get started – use other resources for this, such as those linked-to below. I’ve also skated over some of the more difficult aspects of modding and kitbashing in SL – such as potential LI issues; so again, if you’re starting out, use the resources that are readily available.

Above all, don’t try to tackle complicated tasks from the outset – start simply and experiment. Again, if the house and the parts you use are all Copy, you’re unlikely to lose anything should things go wrong.

(Hopefully) Helpful Links

This is by no means intended to be a comprehensive list.

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