TAPESTRY: The Art of Representation and Abstraction
SketchUp + Kerkythea
Tutorial on SKP+KT textures for Architects
Defining a Custom Texture
In SketchUp
- Construct the face(s) on which you wish to place the texture.
- Invoke the import dialog with File > Import ... and set "Use as texture" before selecting the image you wish to map.
This will produce an image map (aka diffuse color map). There is no provision for transparency, bump, or other more advanced map types.
In Kerkythea
Kerkythea has it's own set of textures, distinct from SketchUp. These textures can have bump maps, transparency maps (called "clip maps" in Kerkythea), etc.
- To make a Kerkythea texture, you use the "Material Editor". There are several ways to get to this info, but the easiest is to select the geometry on which the texture is loaded (or on which you wish to load it). Then click the small spherical icon in the tool bar or type ALT+M.
- In the material editor, look for the blocks labeled "Reflectance", "Bump Mapping" and "Clip Mapping".
- Within the "Reflectance" block, if you RIGHT-CLICK on the word "Diffuse" you will see a small tool palette with four icon options: add color, add bit-map, add procedural, or delete. Click "add bit-map" to call up a file browser which you can use to identify the file on disk.
- In a similar way, you may define bump and clip maps for the texture.
- When you are done, you may want to add the texture to a personal texture library, so you can use it again in the future. Otherwise it is simply part of the current model (and will be replaced the next time you Export from SketchUp).
Defining a "One-poly Mike"
SketchUp does not seem to support transparency-maps, so any geometry that you define will be visible in the rendered image. Strictly speaking, this makes it impossible to do a one-poly figure. However, there is a fairly workable way to do a figure with a limited polygon count....
In SketchUp
- As described above, load and apply an image containing the desired image.
- Orient yourself for a good view of the texture and view it with textures ON.
- With the pencil tool, draw an outline for the figure. Make sure the snap preview shows "on edge" or "on face" for each click (and start with an "on edge".
- The resulting outline will show only the portion of the image you wish to make visible. If necessary, you can clip off more, or infill over-trimmed areas with additional lines.
- It might be a good idea to select the resulting geometry and make a component out of it, checking the "always face camera" option along the way, unless you need them to have a particular relationship to the model geometry.
Things to keep in mind
- Using the "Plugins > Kerkythea Exporter" in SketchUp will OVERWRITE all data in the export pipeline so you want to minimize editing you will have to do in Kerkythea.
- When you Export to Kerkythea, the texture images are exported to a folder in the same folder as your model, named TX_(model name). This folder will include an built-in textures you have applied, as well as custom textures.
- SketchUp faces are two-sided, so you get two texture swatches in the "Entity Info" dialog box. However, only the first of the textures is used in Kerkythea (it's used on both sides) if both are defined. The "undefined" (default) state is shown as a gray+white rectangle divided diagonally.
- To flip a face over in SketchUp you (select one or more faces, then) Edit > Face > Reverse faces
- You can find the default color under the "Colors in Model" list, or select the problematic texture and "Remove" it from the model.
- Photo Textures are extracted from Google Street View and are intended to give your model real-world context. You must provide a face on which to map the texture, and correctly give the model's location.
Last updated: April, 2014