Mostly work related stuff which I would've entered into my "Log book". Instead of hosting it on an intranet site, outsourcing the hosting to blogger!
Saturday, October 22, 2011
exporting mobile contacts and upgrading .NET
Friday, October 21, 2011
Blender QA with Ron Proctor
Ron Proctor is a respected planetarian, and Blender enthusiast, releasing Blender-produced free planetarium shows like Sizing up Space, Expanded View, etc. I asked him some questions over email, and he graciously replied promptly.
Hello Ron,
I'm just starting out with Blender for show production, and tried out your ""Starball"" and fisheye rig at http://webersci.org/blendheads/?p=13
Just wondering - in Blender 2.4, there is an option in Camera settings for Panorama. Is this there somewhere in 2.5 also? Can this be used instead of your fisheye rig?
Thanks for your time.
The panorama setting was moved to the camera properties.
Unfortunately, it does not produce correct fisheye images. A native fisheye camera would be great.
Presently, the only ways to get fisheye out of Blender are:
- Fisheye Camera Rig (Reflective Hemisphere)
- 5 (or 6) camera frustum + external stitcher (such as Paul Bourke's cube2dome).
- Third party renderer (I have no experience with these).
You are welcome to use our fisheye camera rig under the terms of the provided license.
Good luck in your work.
Thanks for the quick reply, Ron.
Are the 3D models of objects like Chandra / Hubble / Voyager spacecraft etc available somewhere? I suppose we could roll our own Planets using spheres and textures.....
You might start at the NASA 3D Repository. Celestia Motherlode also has some resources, but make sure the source data are ok for use.
I've tried to put background images to the rendered scenes using the Blender World -> Texture , choosing Global Co-ordinates for the World Texture.
(details and pictures are at https://hnsws.blogspot.com/2011/10/blurry-background-for-video-on-fulldome.html )
Do you have any other preferred way to add background images to a scene rendered with your fisheye camera rig?
Also - the Blender Game Engine seems to have a Dome mode, with a Fisheye dome camera,
http://wiki.blender.org/index.
Since I'm using exactly the same technique from Paul Bourke
( http://hnsws.blogspot.com/
was wondering if there is some way in which I can get these warped dome images directly rendered to files from the Game Engine and not just interactively displayed using the game engine?
Thanks in advance.
I prefer to use a big UV sphere
Tuesday, October 18, 2011
adding a background image for fulldome images in Blender
This was the background image, and after using it, the result was like this:
Well, not too bad. Perhaps if I fiddled around with the background image, making it bigger, it might improve things? Anyway, the method of using the Alpha channel as given in the tutorial here doesn't work too well because of the fisheye camera rig. When rendered with the fisheye camera, the alpha channel includes the whole circle - since that is what is being reflected on the fisheye rig's mirror. So, the scene when rendered will not include the background image inside the circle at all - only in the corners, which is not useful at all.
One of the comments in the above tutorial mentioned simply using a paper sky in World settings, and then enable Horizon in Influence settings. That works well with normal cameras, but had a problem with the reflection from the fisheye rig - with a ring around the horizon of the fulldome - it looked like this:
Anyway, going through the Blendercookie/CGcookie tutorial was a good learning experience, especially since it took me to his previous tutorial, and I learnt the reason for the scale - dimension problem I noted earlier. Apparently if you change the dimensions of an object in Object mode, the scale goes out of whack. To correct it, he does Ctrl A, and chooses Scale. Then - et voila - the scale goes back to 1.0 and the dimensions are preserved.
Monday, October 17, 2011
blurry background for video on fulldome using Blender
HD video file on fulldome with fisheye camera in Blender
https://blender.stackexchange.com/questions/174750/how-to-make-fisheye-lens-for-camera
Rotation - X = 125, Y = 0, Z = 0
Location - X = 0, Y = 0, Z = 1.3
This gave an effect similar to the video part in the TSPOG show - probably I need to add some blurring on the blank black area outside the video window like in that show. Rendering took around 1 minute per frame with two threads, and 2 minutes per frame with a single thread. Sample fulldome frame was like below.
Saturday, October 15, 2011
ebook using instapaper
rudimentary planet in Blender, also video texture
Things to remember:
- UV mapping means wrapping the texture around the object - U and V are used to describe the 2D mesh since X and Y are already taken!
- For the planet, the mapping used was Co-ordinates = Object, Object = Sphere, Projection = Sphere. (Not Co-ordinates = UV!)
- Smooth shading: as given in Ron Proctor's tip here, using smooth shading makes the sphere look much better. Accessed from Object tools - T after selecting the object.
- The plane could be of the same dimensions as the movie, so for a 4:3 movie, a plane of dimensions x=4 and y=3 is good.
- In such a case, the texture mapping to use is Co-ordinates = Generated, Projection = Flat, and Extension = Clip.
- For ease of placement of camera(s) and the plane, the N key which brings up the properties allows numerical entry of values.
- As mentioned before, Emit=1 and Specular=0 are good for video textures.
- In some tutorials like this one, the rotation animation is done by entering a value like 3600 degrees for 10 turns. But when I tried entering a value of 360 for rotating the camera a full circle, it did nothing. When I tried 340 or 370, the camera moved only by 20 or 10 degrees respectively. So I settled for 180 degrees in my test.
Friday, October 14, 2011
NASA models and more in Blender
- Textures need to be in UV mapping mode for them to be displayed properly in this model - Mapping -> Co-ordinates -> UV - and I had to manually map the texture bitmaps to the relevant materials in the model.
- Blender's Textured Viewport shading only works if object has a UV mapped texture (in general).
- Imported model was extremely large as seen in default Blender view. Scaling it down was easier than moving the camera and lights out.
- Ctrl Alt Numpad 0 puts Camera to current view.
Wednesday, October 12, 2011
getting started with Blender
Today, I dove a bit deeper, to take the first baby steps towards making our own fulldome show. Printed out the cheat sheet from qubodup and went through the first few getting started tutorials again to refresh my memory.
- Right-click to select an object.
- Middle-click and drag to move around in the view-port, with Shift and Ctrl as modifiers for pan and zoom respectively.
- Shift+A to add an object
- N to numerically adjust location and size
- S R and G for Scale, Rotate and Grab, with X Y Z for constrained motion along those axes.
- TAB to toggle Edit mode and Object mode
- Shift+F10 Image Editor (where rendered output is seen)
- Shift+F5 3D viewport
- Numpad 7 1 3 for Top Front Right views, 4 6 8 2 for rotate, 5 for toggling perspective and orthogonal views.
- Numpad . for Zoom to object.
Problems faced:
- Extrude tool seems to Extrude only along the natural face of the object - some sort of constraint somewhere.
- When I change dimensions of an object using N and then render using F12, it is going back to its original dimensions!
Next steps:
Would probably want to make a set of stills or videos move around the dome as in the IBEX show.
Tuesday, October 11, 2011
using Digital Universe to create fulldome content
But maybe instead I can use the video they give for download.
Monday, October 10, 2011
Zalip internet radio and TeluguStream
Sunday, October 02, 2011
iphone 3GS update restore saga
Googling various terms, the first thing I tried was to use TinyUmbrella to kick the phone out of recovery mode, as given here. That did not work. TinyUmbrella was not able to see any info on the phone, not even ECID.
Gathered info including ECID using USBview as given here.
This particular forum post seemed promising - Did I ruin my 3GS . As suggested there, tried the untethered jailbreak with sn0wbreeze, with the tutorial given at this page. Making a bulleted list of the many trials I did - the last two are the successful ones:
- I tried first with the later version of sn0wbreeze, using OS version 4.3.2 instead of 4.2.1. After creating the custom IPSW with sn0wbreeze, iTunes did not allow the update - I thought it was because TinyUmbrella's TSS server was not running. Making a custom IPSW was taking around 5 minutes on my phone.
- At this point, TinyUmbrella was not able to save any blobs - it was not seeing any blobs on the phone. Running iTunes with the TSS server also did not work, it ended with error 1602. The update process in iTunes was taking around 5 minutes.
- The solution for that was to run sn0wbreeze till the end - I thought the phone was already in DFU mode, black screen - but it needed to put the phone in a pwned DFU mode.
- Running sn0wbreeze till the end where it uses iReb to avoid the 16-- errors, the update went till the very end, but then error 37 in iTunes.
- In the above trials, I had chosen New Boot Rom within sn0wbreeze. Perhaps that was the culprit. So made another IPSW with sn0wbreeze, chosing Old Boot Rom.
- This time it went through, iTunes declared it successful, but phone did not boot. It remained in DFU mode even after reboot.
- TinyUmbrella was able to save some blobs now, and it showed 4.1 and 5.0 beta blobs. So tried the same update, with the TSS server running this time. Same result - iTunes success, but phone doesn't boot.
- Tried New Boot Rom IPSW with TSS server - again error 37.
- Tried New Boot Rom IPSW without TSS server - error 3194 this time. "This device is not eligible for the requested build" - so probably I should go with Old Boot Rom and not New.
- Back to making an Old Bootrom IPSW, on a different usb port, without TSS. Stuck at preparing iphone for restore.
- Tried a different tack - since 4.1 blobs are seen in TinyUmbrella, why not try with that one. For this, downloaded sn0wbreeze 2.1. This time, it worked like a charm - running iTunes with TinyUmbrella's TSS server on. The phone booted up. But it is not unlocked yet.
- To unlock 4.1, this page points to this guide - just need to add repo666.ultrasn0w.com to the sources in Cydia (it was already there) and install ultrasn0w using Cydia Search. Did so, rebooted, and the phone is unlocked, working fine.