When you load an OBJ file into Carrara (v8.5 here
in this example), you'll see a choice of options
related to how the OBJ data should be used inside
Carrara. Another method is to load the saved
greyscale elevation map (depth map). This can be
used in Carrara's terrain modeler to reconstruct
the terrain. It takes far less time and memory,
and viewing the result is fast too. You can then
use the advanced shaders for Terrain objects that
Carrara has, or change it to a shader that still
uses your saved texture as well.
You'll notice that Carrara can created the objects
as Facet Meshes or as Vertex Primitives. The
latter is the default. This is useful if you plan
on doing vertex-level editing on the imported
surface. However, it will likely take more memory
and more time to load, because the internal data
structure is quite different when you want to
identify and edit each vertex and facet and line
through the Vertex modeler, vs. just holding a
mesh that is ready to be rendered but doesn't need
editing comparable controls.
For large terrain meshes, it may therefore make
sense to use the Facet Meshes mode.
Note that either way, it can take quite a while to
load such mesh terrain models. If you have a
fairly high resolution image as the unerlying
elevation map, the mesh file in OBJ format can
easily be dozens or hundreds of megabytes in size.
Below is a comparison with an example of a mesh of
1800x1012 elements in the original greyscale
height map from which the terrain mesh was created
in Howler's 3D Designer. (Note that this uses a
modified version of the exporter, which allows for
the u,v addresses to be exported with the mesh.
You can grab
this free update patch for improved OBJ export
The resulting saved OBJ file in this example is
- 278 MB as uncompressed clear text
- 41.2 MB compressed as zip
- 14.6 MB compressed with 7-zip (.7z file).
You'll definitely want to use 7-zip for archiving
Here's the original greyscale elevation map, with
erosion and sediments from 3D Designer:
Here's a texture map for it
Here are renderings in PD Howler's 3D Designer:
Here we have imported the saved OBJ into Carrara
as a mesh, then added the texture in the shader.
Here's a rendering in Carrara, save terrain,
with different camera position added sky
Here we have used the same terrain as a surface
replicator for a fir tree
Method #2 - Reconstructing the Terrain mesh
from the saved Elevation Map