Sculpted Prims I
how to create an object with blender and export it as a sculptie map (UV-texture) for usage in OpenSim or any compatible online world.
We assume, that you have basic knowledge about the blender user interface.
But we still provide enough background information, so that even blender newbies can follow the process. The tutorial works for blender 2.49b and Jass-2
- Creators of “sculpted prims” for OpenSim and similar environments
- Blender noobs (no/low level skills)
- download: jass-2 (binary distribution, contains blender-2.49b, python-2.6.4, primstar-1.0.0 and more)
(*) If Jass-2 is not an option for you, you can download the prerequisites separately:
Transcription (for the blender 2.49b version)
Welcome to our blender tutorial series about sculpted prims. I assume that you are new to blender and maybe this is even your first attempt to make 3D-artwork. So i will guide you through the process of creating a sculpted prim in easy-to-follow steps. I have choosen to create a top-hat. This is not a very complex task, but i can show you many important details about modelling and texturing. At the end of this video you will know the most important concepts about blender, sculpted prims, and about the primstar tool which i will introduce now.
I assume that you have already downloaded and installed blender 2.49b (the current stable release).
And i assume that you have downloaded and installed the primstar tool from the Domino-designs website.
We have already covered these preliminary steps in our basic blender tutorials. And please take your time to watch our blender-primer-tutorial at least once. That will help you find your way through this video. You can find all mentioned tutorials on the machinimatrix-website.
We will use blenders plain and simple out of the box configuration here. I will modify the configuration later to optimize blender for the creation of sculpted prims. So let us first remove the default-cube by pressing ‘x’, and then click on: ‘erase selected objects’. Now we are ready to create a new object by pressing the space bar on the keyboard , and then,
add -> mesh -> sculpt mesh
A dialog opens where you can access a set of parameters for your sculptie. The most important parameter is the base shape to be used. You can choose among 6 base shapesand a couple of more complex pre-defined shapes. Since we want to create a top-hat we will select the most natural starting shape here, a cylinder. For now keep the other parameters with their default values. We will come back to them later.
But please note, that we are working with
- 8 faces in x
- 8 faces in y
- 2 subdivision levels.
We will see later, what that is about and why this is one of the coolest features of prim-star. Ok, it is time to Click on the build-button and create your first blender object.
You can use the middle mouse roll-button to zoom-in and out. This pink outline of the object tells you that it is currently selected. You can hold down the middle mouse button and drag the mouse to examine the object in the 3D-space.
As expected, it is a cylinder and we want to modify it now. So let us switch from Object-mode to edit-mode. You can do that in the mode-selection menu in the bottom line of the current screen. When in edit-mode, you notice a few more interesting things here:
- first, you see a mesh made out of 9 octagons stacked on top of each other. This corresponds to 8 faces in x, and 8 faces in y. If you selected another set of values in the add-sculptie-menu, you would now see a different mesh-configuration here.
- You also see the cylinder rendered as a smooth object. Indeed the mesh is used as a set of control-points for the cylinder. The number of vertices on the cylinder controlled by each mesh-point is determined by the subdivision level. Each level adds a factor of 4, hence with 2 subdivision levels, each mesh-point controls 16 cylinder vertices.
For now we just work with the control points. We will learn later, how to take more control, even full control over each individual vertex of the cylinder. For now we are happy with just modifying the controlpoints.
Ok, the first thing we need to do is closing the top of the cylinder. For this purpose we switch to front-view. You can do that in the view-selection menu in the bottom line of the current screen. Now i deselect all vertices of the mesh by pressing ‘a’ once.
Now i want to select the top vertices. Press ‘b’ to open the border-select-tool, then click the left mouse-key and while holding the mouse key down drag the rubber-band around the vertices which you want to select. When i now release the left mouse-key all enclosed vertices get selected.
Now i will scale all vertices down to 0. Press “s”, then drag the mouse towards the center of the selected octagon.
As a shortcut simply enter “0” on the key-board and press the Enter button.
Now the cylinder-top is closed. But we want to make the top more flat. I go back to front view, and then i grab the selected vertices by pressing “g” followed by “z”. Now i can move the vertices along the z-axis until they align with the next lower octagon of vertices. By now we are almost finished. We only need to model the brim.
I select the bottom row of vertices and scale them up a bit. Again i use the border-select tool by pressing “b”, left click, drag, and release the left mouse button. Then i scale by pressing “s”, then drag the mouse and left click again. Finally i move the whole-set of selected vertices a bit upwards to align them with the next-higher row of vertices. finished. Now we need to know how this object can be transported to the target system namely OpenSim.
The answer is: We must create a sculpt-map. A sculptmap is a 2D-mapping of the vertices in your object. This mapping is calculated by primstar, and automatically translated into an image. And this image can be accessed by use of the UV-image editor. All we have to do now, is to configure a split-screen and open the UV-image editor. This will become very handy in the course of this tutorial.
Move your mouse-button to the upper-part of the screen until you see a double-headed arrow-key. After pressing the right mouse-button a small window appears. Select “split area”. A vertical line appears and follows your mouse-movement.
Move the line around until you have found your preferred split-point then click the left mouse-button.
Now you see two windows showing the same content. In the right window go to the “window-type-selector” and choose the UV-image editor. If the display is too small You can use the middle mouse roll-button to scale it up a bit
And now comes the magic part:
- First, go to object-mode. This is important to see the sculptie-map immediately.
- Then , Go to render , “bake sculpt meshes”.
- There just klick on the bake-button, leaving the default settings untouched for the moment.
- your sculptie-map appears in the window on the right-side.
- And now finally open the image-sub-menu and save your sculpt-map to your hard-drive.
This map is what we have to import to our virtual world now. Note, that this image will by default be stored in TGA-format. Now go to your viewer and import the just created image into your inventory. When you transmit the image, be sure, that you use loss-less compression, Otherwise your sculpted prim might look a bit broken.
For our first attempt to create a sculpted prim this result is not too bad, don’t you think ?
But hold on! Look what happens when i take a closer look under the hat. not good! The object is transparent from the inner side. The brim disappears. Now how can we explain this ?
Well, the reason is simple: sculpted prims have only one side. Look here. These are 4 basic shapes for sculpted prims. The plane, Nicely visible from one side. But fully transparent from the other side. The cylinder, The outside is ok, but the whole in-side is invisible. The sphere and the Torus. These two are ok. But this is only so because they do have only one side. The inner side simply does not exist, hence we see no problem here.
So what can we do to make this cylinder work better in our 3D-world ? Lets go back to the moment where i create the brim. Now we select the secnd lowest row of vertices and scale them up as we did before. And then we take the lowest row of vertices but now we scale them down a bit. Finally we scale down the three bottom-most rows in “z”. The effect is, that now we have modelled the brim with 2 sides instead of only one side. And now the hat also looks good from below.
Please note that i have not fully closed the hat. As long as the hat is placed on a head there is no problem here.
Only if you intend to hold the hat in your hands it may become necessary to model the full in-side part.
We are now at the end of this tutorial. I have shown you
- how to create a basic shape with primstar
- how to examine the objects
- how to select vertices with the border select tool
- how to scale parts of your model.
- You know how to bake a sculptmap
- and how to export it to OpenSim (or your preferred online world).
- And now you also know why sometimes parts of a sculptie unexpectedly disappear and what you can do in order to avoid that.
In the next tutorial We will proceed with a few more-advanced modelling-tools,
and make this cylinder look more appealing.
Until then have fun.
See you later!