[x3d-public] Updation of PTM (draft notes)

[Don Brutzman]

Kwan Hee Yoo, thanks for your presentation today.

Other participants: Kwan Hee Yoo, Myeong Won Lee, Dick Puk, Joe Williams, William Glascoe and yours truly.

On 2/25/2015 5:39 AM, Kwan-Hee Yoo wrote:
> Hi, Don.
>
> How are you?

Very good, thanks.  Good to hear you today too.

> I am preparing the material for tomorrow's meeting on perspective texture mapping
> which is made by considering your comments.
> Please, review the material.

Comments follow.  I will start from letter (o) since comments (a) through (n) already appear below.:

o. Slide 2: do you have a url to your video?  would you like to put your demo video online at web3d.org?  Or send it to me for inclusion on Web3D youtube site?

p. Slide 3:  nice figures.  We could create our own, in 2D or X3D.  You may be interested to look at

http://X3dGraphics.com/examples/X3dForWebAuthors/Chapter14-Prototypes
http://X3dGraphics.com/examples/X3dForWebAuthors/Chapter14-Prototypes/ViewFrustumExample.x3d
http://X3dGraphics.com/examples/X3dForWebAuthors/Chapter14-Prototypes/ViewFrustumPrototype.x3d

http://x3dgraphics.com/examples/X3dForWebAuthors/Chapter14-Prototypes/ViewFrustumOverheadView.png
http://x3dgraphics.com/examples/X3dForWebAuthors/Chapter14-Prototypes/ViewFrustumObliqueView.png
http://x3dgraphics.com/examples/X3dForWebAuthors/Chapter14-Prototypes/ViewpointCalculator.png

We could create a similar prototype to visualize these new nodes, if you want.  Should be fun!

q. Slide 4: probably need to list problems with other designs that didn't work as well.  Perhaps add your old slides as a backup.

r. Slides 6 and 7:  is it possible to implement these nodes as X3D prototypes?  Might be interesting, even if it is only as a stub.

My understanding is that you are writing FreeWrl source using Perl.

It would also be interesting to see if someone wants to implement these as an X3DOM component.

s.Slide 7: aspectRatio not needed as an input since that is provided by the image being used.

However aspectRatio might be interesting and helpful to authors as an outputOnly field.

t. Slides 6 7 and 8.  (Dick Puk) why are you using location/direction fields when Viewpoint has position/orientation?

u. Slide 7.  Why include upVector, it has not been needed for other X3D nodes which instead use local coordinate frame.

v. Slide 7 and 8, other differences noted with Viewpoint and OrthoViewpoint respectively.  Need fieldOfView and centerOfRotation for both nodes.

w. Slide 7 and 8, attenuation.  Perhaps TextureProjectorPerspective should attenuate like PointLight, and TextureProjectorParallel doesn't attenuate, similar to DirectionalLight.

Patterning after existing light nodes, and lighting models, certainly makes browser implementation pretty easy.

Slide 9, ProjectorLight.  This proposed node does not appear to be necessary, authors can use other existing nodes instead (including these).


> See you tomorrow morning.
>
> Best Regards,
> Kwan-Hee Yoo
>
> -----Original Message-----
> From: Don Brutzman [mailto:brutzman at nps.edu]
> Sent: Thursday, February 05, 2015 11:47 AM
> To: khyoo at chungbuk.ac.kr
> Cc: Joe D Williams; X3D Graphics public mailing list
> Subject: Re: Updation of PTM (draft notes)
>
> Kwan Hee Yoo, thank you for the in-depth discussion call today with Joe and I.
>
> Your slides are attached.  The proposed nodes that treat a texture like a light source are really interesting!
>
> List of comments:
>
> a.  slide 10, X3DProjetiveTextureNode
>
> spelling: X3DProjectiveTextureNode
>
> maybe better name to match other nodes:
>
> 	X3DTextureProjectorNode
>
> b. Slide 11 and 12, Consistent names, re-sorted:
>
> 	TextureProjectorPerspective
> 	TextureProjectorParallel
>
> c.  Slide 11, Get rid of aspectRatio since it is already defined by the ImageTexturee
>
> d.  Slides 10, 11 and 12, add PixelTexture to ImageTexture and MovieTexture
>
> e.  Split out nearFar into two separate fields
>
> Potential names nearDistance farDistance
>
> Note that farDistance is the same as "radius" field for DirectionalLight and SpotLight
>
> (Incidentally nearDistance is somewhat similar to the first value of NavigationInfo avatarSize field.)
>
> f.  Missing: attenuation field for TextureProjectorPerspective, same as SpotLight
>
> g.  Slide 11, fieldOfView value should be radians
>
> h.  Slide 12, TextureProjectParallel needs to define what is actual width and height for given aspectRatio pixel dimensions
>
> i.  Slide 12, I still don't understand "volume" is - perhaps that is intended to be similar to width and height in previous point?
>
> j.  Consider whether to include TextureTransform
>
> k.  A few simple hand diagrams of geometry might help
>
> l.  Add slides for DirectionalLight, PointLight, SpotLight - helpful for comparisons.
>
> You might also find that these tooltips are interesting:
>
> http://www.web3d.org/x3d/content/X3dTooltips.html#DirectionalLight
> http://www.web3d.org/x3d/content/X3dTooltips.html#PointLight
> http://www.web3d.org/x3d/content/X3dTooltips.html#SpotLight
>
> m.  Looks like we have some bad characters in the Korean Tooltips:
> http://www.web3d.org/x3d/content/X3dTooltipsKorean.html#SpotLight
> http://www.web3d.org/x3d/content/X3dTooltipsKorean.html#PointLight
> http://www.web3d.org/x3d/content/X3dTooltipsKorean.html#SpotLight
>
> n.  Slide 14.  I don't yet understand what this other node is adding that is different from the other nodes.  Please add more description so that we understand.
>
> We will meet again in 3 weeks, same time (5 pm California on 25th, 10 am Korea on 26th).  Web3D Calendar entry added.
>
> Thank you!!
>
> On 2/2/2015 11:44 PM, Kwan-Hee Yoo wrote:
>> Dear Don,
>>
>> Did you come back to home well?
>> After discussing on PTM, I update PTM material.
>> The material includes PTM abstract node and real PTM nodes.
>>
>> The material will be used with you to discuss PTM at Feb. 5(Thursday) 10:00 AM (Korean Time).
>> After fixing out NODEs for PTM, we will re-implement PTM into FreeWRL.
>>
>> Thanks.
>> Kwan-Hee Yoo

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman