I'm new to blender and could not find this in help files. Can blender be used to drape a 2D image onto a 3D point cloud or mesh? If yes, can someone point me to a tutorial on that?
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1$\begingroup$ You could try a shrinkwrap modifier, see blender.stackexchange.com/q/7028/599 $\endgroup$– gandalf3Commented Jun 30, 2014 at 20:20
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$\begingroup$ Thanks. I guess this is good for creating surfaces out of point clouds. What I want is the ability to drape an image onto a mesh or point cloud. $\endgroup$– user5027Commented Jun 30, 2014 at 21:04
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$\begingroup$ What do you mean by "drape"? Do you want to texture it? Or drape a mesh with a texture (like stacker's answer)? $\endgroup$– gandalf3Commented Jun 30, 2014 at 21:07
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$\begingroup$ I actually have point cloud of a surface from a LiDAR unit as well as a picture taken with a camera. I want to drape that image over the point cloud to get a 3D realistic model of the surface. $\endgroup$– user5027Commented Jun 30, 2014 at 21:19
3 Answers
To drape an image over a 3d mesh is easy. First bring you image into blender, I'd use the import image as plane add on. Next, as gandalf3 said, use a shrink wrap modifier to drop it over the mesh. by doing that you can avoid any distortion that would occur when using the cloth simulator.
If you want to project camera data on to a LIDAR scan, I would use a third method:
- Match your 3D camera to the position of the camera that took the photograph.
- Next select your mesh(LIDAR scan), and add a UVProject Modifier.
- Set the projector to you camera you positioned in step one.
- Then set your image in the image box.
- Uv Unwrap your mesh(LIDAR scan), It does not matter how. Also change the UV option in the UV project modifier to match the name of the UV map you just created.
- Add a texture, and set the image to be your photograph. also set the UV map.
Done, your mesh(LIDAR scan) has been textured!
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$\begingroup$ Sounds like it would work but the position of the camera is not known. I guess shrinkwrap would be the next closest option? $\endgroup$– user5027Commented Jun 30, 2014 at 22:58
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$\begingroup$ You can solve for the position of the camera using something like blam(github.com/stuffmatic/blam), or eyeballing it. $\endgroup$ Commented Jul 1, 2014 at 0:21
I've done this kind of thing before-adding an orthoquad photo as a texture on surface mesh to make a realistic land form. The crucial step is going to be converting that Lidar data into a TIN surface (triangulated irregular network) that you can then export as a mesh to Blender. If your LIDAR data comes from a survey firm, then the best option is to ask them to create a DXF file for you. You can then open that in DRaftsight (it's free: Draftsight.com) and export it to STL-which you can then import into Blender. Another option: I found a web portal that says registration is free and that members have access to Lidar conversion tools that can craete DXF or Collada files. Here is their URL: https://www.lidar-online.com/users-login.php Finaly, If you acquired the point data from one of the public domain USGS sites (like LaBIns.org) then check to see if you can get the data in DEM format. The DEM is a zip file containing amoung other things, a raster image of a displacement map. Elevation values are represented as shades of gray. change the file extension to .zip so that you can view it in your file system. Extract that and then you can apply image as a displacement modifier to a plane, or wire it to the displacement channel of your ground-plane material One final bit of advice on using these files in Blender. Before you import them, you need to be sure of your units and precision settings. Cadastral data is usually georeferenced using special coordinate systems. Your data set could come in very far from the origin in your scene or might be expressed in lattitude/longitude, so you should move and scale your data after you import it.
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$\begingroup$ Thanks, John. I'm using VRMesh to create the TIN and can export the mesh in blender as well. I couldn't quite get how you did the draping. Can you please elaborate on it a bit? Thanks. $\endgroup$– user5027Commented Jun 30, 2014 at 22:43
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$\begingroup$ If your iamge is ortho-rectified (and most Arial mapping images are), then you can just do a simple UV projection. Edit the surface tin, set the view to orthographic looking at it from the top down, select all of the triangles in the mesh (A), go into the UV Unwrap (U) and select "Project from View" $\endgroup$ Commented Jul 1, 2014 at 14:37
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$\begingroup$ The image is not orthorectified. It's actually not an aerial image, rather of a vertical surface taken with a simple handheld camera. $\endgroup$– user5027Commented Jul 1, 2014 at 16:53
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$\begingroup$ Sounds like GiantCowFilms had the right approach, then. $\endgroup$ Commented Jul 3, 2014 at 15:38