If you are hunting for a zbrush alternative, please check out Sculptris, which is a 3D, digital sculpting&painting freeware. You can use the left and right mouse buttons to sculpt and build the 3d model of your own and export it to wavefront obj format. Sculptris is portable and its size is only 3.06M.
Use the left and right mouse buttons to sculpt. Middle mouse button rotates the view. You can also hold Alt and use the left mouse button to do the same.
There is pressure sensitivity for Wacom-compatible tablets. See below for navigation shortcuts.
Select a tool from the palette and apply it using the left or right mouse button. Left mouse button is the default/positive effect of the tool, while right mouse button is the inverse/negative effect. You can control the size and strength of each tool’s brush using the two main sliders.
Remember that you can undo an operation using Ctrl+Z if it doesn’t turn out the way you intended.
The ‘detail’ slider controls how detailed the brush stroke will be – more triangles will be added to better describe the shapes you put down. It is helpful setting this to zero if you want to tweak some areas without adding more detail. Press W to activate wireframe view if you want to see how the triangle mesh looks.
You can change the visual material using the ‘material’ slider. Materials are stored as images in the materials folder.
Press the paint button to calculate a mapping for the object and switch to paint mode. Here you can paint color on the surface using a round brush or texture images. You can also paint a bumpmaps for finer detail.
Multiple materials can be added if you have a shader-capable graphics card, and you can mask each material individually to control which areas it will cover.
There is a general-purpose selection mask which can be edited and toggled using the checkboxes on the left or the M key. This selection mask will apply to all painting operations.
Masks (material or selection) can be copied and pasted using Ctrl+C/V, and inverted using Ctrl+I.
Heightmasking can be used to paint inside cavities or on top of parts that stick out. It will also work for bumpmaps. You’ll have to try it out to see how it really works in different scenarios.
There is also an option to export the current view as a layered PSD file where you can paint color that will be projected back onto the model when you import the image again. Paint only on the layer called “paint”, and only use the “normal” blending mode. You can do whatever editing you like, but the end result needs to match this format for it to work.
Before going into paint mode, you can enable “UV deformation mode”, which will allow you to deform the mesh such that selected areas get larger surface area and thereby higher texel density in the following mapping process. This is a one-shot operation that is not saved with the file. If you leave UV deformation it will discard your changes. This mode can also allow some control over automatic seam placement depending on how you introduce or remove corners (by smoothing, for instance).
The “Tight mapping” checkbox will result in less texture stretching for low-poly areas, so try that if you need it.
Download here: http://download.cnet.com/Sculptris/3000-6677_4-75211273.html
Operating system supported: Windows XP/Vista/Windows 7.
Just uncompress the package and run Sculptris.exe. For Controls/shortcuts, see documentation.txt.
If you like Sculptris, you could donate to the author via paypal or VISA : http://www.sculptris.com/