Online 3D file viewing?

[Martin Laverty]

Erm, SVG certainly does not belong to Adobe, nor did they specify it: it is a W3C specification
(Wikipedia has a good entry - http://en.wikipedia.org/wiki/Scalable_Vector_Graphics).
In fact, although Adobe's plugin for IE is very good - indeed, perhaps the best implementation for most purposes - they actually withdrew support for it in January 2009, having ceased any development soon after they purchased Flash.

 

[jarvist]

to do this in SVG means using JavaScript which is a wholly interpreted language, so it is much slower than Java and ActionScript which get compiled to Byte Code.

There is a massive effort to improve JavaScript speed, methods include JIT compilation and register based virtual machines. The difference in performance is certainly narrowing, and with the vast complicated javascript web applications out there & commercial backing, would only be expected to decrease.

Eventually we should also get WebGL, and there's the O3D javascript library if you fancy playing with this, I wouldn't be surprised if it or something similar ends up in flash too.

Just a note on the stereo image question -- there's lots of ways to do it, but one pretty good way is simply a 15 degree +/- 'rocking' which lets your brain figure out the depth perception without the strain + complexity of cross-eyed stereo / anaglyph coloured glasses / shutter glasses. I always find myself doing this manually with Aven by tapping to reverse the direction of cave rotation.

 

[TheBitterEnd]

Martin Laverty:  someone always has to ruin a good flame war with facts 

Dunno where that came from, it's not like I haven't been to the W3C SVG site exactly one bazillion times

 

[footleg]

Footleg, the Java version works fine for me in Firefox 3.6.13 - like you said it is probably a security setting somewhere. And of course flash is an ActiveX control...

I possibly confused things with my last post. Flash works fine in Firefox. There is a flash plug-in for Firefox, and an ActiveX control for IE. It was actually the Java where I had security problems. IE was very unhappy about the Java page and I had to disable security to view it. Firefox just did not display it, but I found out later that when installing a 64bit JDK I had messed up the Java plug-in in my Firefox browser. So that might be why I could not get the Java page to work in Firefox.

 

[footleg]

SVG means using JavaScript which is a wholly interpreted language, so it is much slower than Java and ActionScript which get compiled to Byte Code. So for tens to hundreds of points it's ok, but for thousands it's too slow.

I just tried that link to Julian's VML stuff, and it absolutly flies in my browser. No performance problems at all. Where as the earlier SVG based page that sirch2 posted was very slow. So there is something different there.

 

[TheBitterEnd]

Footleg: starter for ten ... realtime 3D

 

[TheBitterEnd]

It now does surfaces -  see

http://chris-h.me.uk/loch/RabbitViewer.html

IE worked fine but Firefox was reluctant to reload the JAR - I had to got to Control Panel -> Java, then on the General Tab - Temporary Internet Files -> Settings -> Delete Files. Then I had to stop and restart Firefox! (Starts to make the flash idea look like a winner).

DOES ANYONE have any bigger .lox examples that use surfaces (doesn't look like the UBSS ones do). I cut a corner with this version and it may need optimising for bigger files - but some test data would be good.

 

[TheBitterEnd]

When I say "surface" I mean "Scap" (at least that's what it is called in the Loch source code) - a set of triangles that represents a wall, etc. I haven't done bitmaps yet (nor LRUD which I really ought to ...).

 

[Duncan Price]

Try this file: http://www.sump4.com/downloads/hillwithy.lox

 

[TheBitterEnd]

Here's the latest, it now has the surface bitmap in a limited way (see note below) and you can turn on/off various features.

http://chris-h.me.uk/loch/LochViewer.php

With everything turned on, on big surveys such as Charterhouse, it is pretty jerky, best to turn everything except the centre line off to rotate/pan/zoom then turn things back on.

Note on Bitmaps - I haven't implemented skew/rotate for the bitmap tiles. What this means is that when you look at the plan view, the bitmap looks OK, but as you rotate the view the bitmap starts to look crappy. It is going to add a decent computing overhead to implement the skew/rotate and I am wondering if the performance hit is worth it? Let me know what you think.

 

[footleg]

Footleg: starter for ten ... realtime 3D

Is this what you were referring too? This looks promising.
http://www.uselesspickles.com/triangles/

 

[TheBitterEnd]

Finally got around to writing some of this up here.

I have also split off the bitmap drawing into a separate thread, so it draws the lines and polygons and handles mouse activity in one thread and draws the bitmap separately. That way you don't have to wait for the bitmap to be drawn before you can move the lines and polygons.
Try it here

Below is a screen grab of part of the Charterhouse survey (data courtesy of UBSS)

 

[graham]

That screen grab was taken from a very peculiar angle.

 

[TheBitterEnd]

It needs testing by someone who knows what it should look like. I wouldn't be surprised if the cave was upside down or back to front

 

[graham]

It needs testing by someone who knows what it should look like. I wouldn't be surprised if the cave was upside down or back to front

I should know what it looks like better than most. I'll send you a PM.

 

[TheBitterEnd]

So how do I show the surface bitmap in Loch?

 

[graham]

So how do I show the surface bitmap in Loch?

If there is one present it should show automatically.

 

[TheBitterEnd]

I see the surface as shaded polygons but not the bitmap. I've tried several files, all of which have bitmaps - al least they show up in my viewer (albeit the wrong way round)

 

[footleg]

I've had the same problem with some graphics cards. So on some computers the surface bitmap does not appear. On others it works fine. Works fine on a VMWare virtual machine which is my fall back option on awkward hardware.

 

[TheBitterEnd]

thanks footleg, nice to know I wasn't missing something obvious