I’m a brand new user of Blender, though not to 3D. I’m trying to import a large earth terrain model into Blender as a DXF. The model imports fine, and looks perfect in Top (ortho) view. However, if I rotate the view Blender seems to be doing some sort of front/back plane clip, so that only the center portion of the mesh is shown.
Here is a screen shot:
As I dynamically rotate the view different portions far and near to the viewpoint location disappear and re-appear.
In the 3D Viewport header goto View, View Properties and set the Clipping distances. You could anso just scale the object to fit the existing clipping values.
First let me say that I really appreciate the fast response. I’ve got high hopes for Blender and with help bouncing back so quickly is certainly encouraging!
Okay, so I had found the view clip settings before but setting them at their maximum (0-1000) didn’t fix the problem because, as it turns out, the model was just too darned big! I scaled the object down (significantly) and all’s well.
EXCEPT…
Now I have questions regarding the size of objects in Blender. As you might have guessed by my inquiry about loading up a huge earth terrain model, I’m going to be using Blender (hopefully) to render some very large areas. I’m in civil engineering and plan to do static and animated exhibits of our bridge and road projects, if you’re interested.
In any case, I would like to know how best to work on such large (in physical size, not file size) 3D environments in Blender. With the clipping limit of 0-1000 not managing to encompass my original mesh I need to know what to do.
My first thought was to determine exactly how big the imported mesh was in the first place (in real-world units). Unfortunately, looking at the object properties I’m given the XYZ size as 1.0. This is obviously the scale factor of the original model and not, as I’d hoped, the size of the mesh in units like feet, inches, meters, etc. How do I find the physical size of an object in Blender?
Also, your suggestion of scaling down the model to fit within the view clip range worked, but if I’m working with a mesh that’s not 1:1 scale, won’t things like light falloff and other distance-related computations be inaccurate? Some of what I need to do is show lighting studies of our engineering projects and will need fairly accurate lighting in my renderings.
In any case, I would like to know how best to work on such large (in physical size, not file size) 3D environments in Blender. With the clipping limit of 0-1000 not managing to encompass my original mesh I need to know what
Measurement is arbitrary in Blender; the grid is divided into Blender Units (BU), and you can substitute one BU with any other unit you choose. In the 3D window header View >> View Properties allows you to change divisions so both Metric and Imperial are possible and at a larger scale Miles and Kilometers. You have to decide if that’s good enough.
Unfortunately, looking at the object properties I’m given the XYZ size as 1.0. This is obviously the scale factor of the original model and not, as I’d hoped, the size of the mesh in units like feet, inches, meters, etc. How do I find the physical size of an object in Blender?
Hit N in the Viewport and in the Transform Properties the Dim(ention)s are size in BU’s.
Also, your suggestion of scaling down the model to fit within the view clip range worked, but if I’m working with a mesh that’s not 1:1 scale, won’t things like light falloff and other distance-related computations be inaccurate? Some of what I need to do is show lighting studies of our engineering projects and will need fairly accurate lighting in my renderings.
Cough… as you may note from my reply thus far Blender isn’t exactly suited to Physics Engineering. That said, there is a lot you can do with it though it means getting to know some of it’s deepest secrets. Lights, or light values, are pretty generic in Blender. You may think of using a renderer like Maxwell, Indigo or even good old Povray/MegaPov where you can edit files for exactness. Much of what I have said here can be addressed via Python. Look in the Scripts Window under Wizards at KlopUtils for a nifty Python script that may or may not be of help with Scale and allignment. You can open that up in the Text Editor (or NotePad) to see the actual scripting.
I would think, offhand, that if you scaled your mesh down to where a large commercial building was 100x100 bu, about 1bu per foot, that any lighting would be very doable and realistic and fine-grained enough for any engineering, especially bridges, and still be accurate to scale. Blender is used quite a bit in architecture, for large apt buildings and the like.
I created the terrain mesh from survey data collected by my company’s survey department. I then import it into MicroStation via our engineering application, Geopak. I simply exported the triangulated terrain model elements from MicroStation to a DXF.
