Onion Dome Roof


Onion Dome Roof 200

Onion Dome Roof

A step-by-step tutorial on how to create an Onion Dome Roof with Rokuro, an easy, free program for creating sculpt maps & mesh objects.

This Tutorial

This is a easy project beginning builders can handle. Experienced creators will find Rokuro a quick tool for creating simple mesh or sculpt objects.

Rokuro can be used to create symmetrically circular objects such as a bowl, lampshade, carved post, or column. Objects that you might turn on a lathe or potters’ wheel in rl. It takes no special skills & you can create sculpt or mesh objects with it in a a few minutes.

In this tutorial you will learn how to use Rokuro to create a sculpt &/or mesh Onion Dome Roof. In addition, you’ll learn how to texture objects created in Rokuro. I’ll also cover uploading mesh into virtual worlds.

You need:

  • Ability to download, unzip, & run Rokuro on your system.
  • A virtual world where you can upload mesh & textures & rezz objects.
  • Optional: a graphics program for creating custom images

I strongly suggest that you do not skip steps. Most problems that occur are because of skipped steps. Slow down & enjoy the process – it’s supposed to be fun!

Download Rokuro

Rokuro is a small free program that does not require being installed. Download Rokuro, unzip it, & run the executable. Rokuro is Windows 32/64 bit & OSX 32 bit compatible. You can use Rokuro on Linux using Wine.

Background Guide

Screenshot 1 - Rokuro Default Open

Open Rokuro by clicking the executable file. You’ll see two panes: the edit pane on the right & the preview pane on the left.

You’ll also see, in the edit pane, a square drawn with a fine line. Along the line are red, blue, gray, & black squares & circles. These are the contact points. You can drag them around the edit pane. The line will follow the points as you work, forming the outline of one side of your project.

Your resulting sculpt or mesh object will be generated in a circular shape horizontally. The widths will be determined by the placement of the contact points in the right half of the edit pane & be mirrored on the left side of the edit pane.

Don’t worry about proportions. You can adjust the aspect ratio of your object inworld.

Onion Dome Roof Guide

Now you need a background image to use as a guide for your Onion Dome Roof. Right click the image to the right & save it to your hard drive in a location where you can find it again.

Screenshot 2 - Load Background

In the Rokuro Menu Bar go to View > Load Background & in the pop-up navigate to the the background guide you downloaded: Onion Dome Roof Guide.

Screenshot 3 - Display Background

In the menu to View > Disp Background & click it. The guide will load in the edit pane of the Rokuro window.

Screenshot 4 - Level of Detail

Go to View > Level of Detail & click ‘Near’.

[alert heading=”TIP:” type=”info”]Always work on your Rokuro projects with ‘Near’ selected so all the contact points can be moved.[/alert]

Draw Your Onion Dome Roof Shape

Using the image as your guide, drag and drop Rokuro’s contact points to closely follow the outline of the Onion Dome Roof guide.

Screenshot 5 - First & Last Points

Start by pulling the first contact point all the way up as far as it will go. Then pull the last contact point down as far as it will go.

Screenshot 6 - Drag Points

Distribute the other contact points along the Onion Dome Guide’s outline on the right half of the edit pane.

[alert heading=”TIP:” type=”info”]You will find that putting the contact points closer on curvier sections and farther apart on straight lines will give you a smoother shape.[/alert]

Screenshot 7 - Viewing Project

Space them so they follow the outline, forming a smooth shape. On the left half of the edit pane you can see how smooth the outline is & where it may need some adjustment – see #2 in the screenshot.

Click & drag the image in the preview pane to see what your completed project looks like from various angles – see #3 in the screenshot.

Adjust the size of the two panes with the resize grip in the center of the border between them – see screenshot.

Bounding Box

Screenshot 8 - Preview Pane

Notice the white box outline around your shape in the preview pane. This represents the ‘bounding box.

Sculpted prims are like a hologram image contained inside an invisible box. Collisions will occur at the boundaries of the bounding box. Unless set to phantom in your virtual world build window, they have a physical existence of the bounding box rather than the shape you actually see.

Try to fit shapes you create in Rokuro into the entire area allowed, even if it means ‘stretching’ your shape out of correct height or width proportions. This way your objects will have better collision physics inworld. You can adust the proportions inworld.

Creating Your Own Guides

While I’m speaking about the bounding box, let me take a moment to explain how to create good guides for use in Rokuro on future projects that will work better in virtual worlds.

Screenshot - Cropping & Resizing Custom Guide

You can create your own guides for use in Rokuro from photos or drawings in any graphics program that crops & resizes images.

I recommend that when doing so, you crop your image to fit tightly against the borders of your image and then resize the image to a square: making the height and width the same size. Two to three hundred pixels should be fine for most images.

My guide is 600×600 pixels but only because I wanted you to be able to see the contact points clearly. You can save your guides as .png, .jpg, .bmp, or .gif image formats.

Save As a Sculpt Map

IMAGE – Screenshot 9 – Save.png

When you are satisfied with your Onion Dome Roof shape in Rokuro, go to File > Save (Ctrl-Alt-S).

Screenshot 10a - Save Options - tga

In the popup window navigate to where you want to save your Onion Dome Roof files. Give your file a name. Click to get the drop down menu below the name box & select ‘TGA’. Click ‘Save’.

Upload Your Sculpt Map

Open your virtual world viewer & login to your virtual world. In the viewer Menu bar locate the upload image option. In mine it’s at: Build > Upload > Image or Ctrl-U. Your viewer may have a different menu layout.

Navigate to where you saved your files & locate the .tga sculpt map & click ‘Open’.

In the Texture Upload window rename your sculpt map texture if you need to & give it a description.

Make sure ‘Use lossless compression’ is ticked. For sculpt maps this is essential for obtaining a good reproduction of the shape you created. The pixels in the sculpt map image serve as a sort of code that says how to display your shape in it’s bounding box. Any accidental tweaking of the image therefor tweaks the shape of your sculpt once created.

In ‘Preview image as’, change the drop down menu to ‘Sculpted Prim’. Use your mouse to rotate and zoom on the sculpt image or hold ctrl and use your mouse to tilt and zoom to see if your sculpt shape looks good.

Click the Upload button if you are satisfied with the shape. Your sculpt map will be saved to your Texture folder in your Inventory.

Create Your Sculpted Prim

Rezz Object

Open your Build Window, Ctrl-B, & rezz a prim.

Name Mesh Object

Go to the General tab of the Build window & name your prim ‘Onion Dome Roof Sculpt Map’ or something descriptive so you will know what it is & can locate it in your inventory easily.


Go to the Object tab & change prim type to ‘Sculpted’ in the drop down menu in the right hand column.

Go to your inventory & locate the ‘Onion Dome Roof Sculpt UV Map’ texture you uploaded. It will be in your Texture folder.


Drag & drop the ‘Onion Dome Roof Sculpt Map’ texture from your inventory to the rainbow colored ‘Sculpt Texture’ box.

Resize Object

Go to the Object tab & change:

X = 1,
Y = 1,
Z = 2

Or, if your viewer has the ‘C’ & ‘P’ copy and paste buttons, just highlight and copy:

[code]<1.0, 1.0, 2.0>[/code]

Include the brackets and, in the Build window Object tab, click the button labeled ‘P’ located at the end of the Z size box. This will paste the size parameters into all three size boxes.

[accordion id=”how-to”]
[accordion_item title=”Troubleshooting Any Problems” parent_id=”how-to” open=”false”]
If your prim fails to turn into an Onion Dome Roof, remains gray, or looks very strange shaped double and triple check:

1) Is the texture in the Sculpt Texture box in the Build window Object tab a rainbow colored image? If not, it’s probably the wrong texture. Locate it in your inventory again, make sure it’s the rainbow colored sculpt map, & drag it to the Sculpt Texture box again.

2) Check if you selected the correct image to upload. Did you see an Onion Dome Roof in the preview pane of the Image Upload window? If not or not sure, reupload it again, making sure to select the correct image.

3) Did you tick the ‘Use Lossless Compression’ in the Image Upload window? Reupload it again, making sure ‘Use Lossless Compression’ is ticked if you are not sure.

4) Sometimes image rezzing takes a little time & sometimes world servers are being buggy. If your sculpt image remains gray instead of rainbow colored you can try waiting a while & try it again later. You can also try working in a less laggy area where there are less images around for your computer to deal with.

Save As Mesh

Screenshot 10b - Save Options - Collada

Again, go to File > Save (Ctrl-Alt-S). Give your file the same name as you did for your sculpt map file. Click the drop down menu below the name box &, this time, select ‘Collada’.

Screenshot 11 - Collada Options Physics Shape

You’ll get a Collada Options popup. Tick all three boxes & in the drop down menu at the bottom, select ‘Optimize vertices – Keep UVMap’. Click ‘OK’. The files should save to the same folder your .tga file saved in.

With these settings you’ll get a mesh collada .dae file for each of four LoD levels & the physics file. You’ll also get a copy of the UVMap that is shown applied to the shape in the preview pane. We’ll see how to use these files when we go over uploading your mesh Onion Dome Roof to your world.

Upload Your Mesh Onion Dome Roof

In your viewer go to Build > Upload > Mesh Model in the menu bar. The menu item may be in a different location depending on what viewer you are using.

Navigate to where you saved your Onion Dome Roof Mesh Model and open it.


Post your questions in the comment section below & I’ll answer it as soon as possible. Please try to be as specific as possible so I can figure out what it is you are asking.

Remona Stormborn

Co-Owner of Gaia Foundation in the Great Canadian Grid. Owner of the Builders Resource Center, Rose City Design, & IDEA! in the Great Canadian Grid & InWorldz.

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