Java-Gaming.org    
Featured games (81)
games approved by the League of Dukes
Games in Showcase (499)
Games in Android Showcase (118)
games submitted by our members
Games in WIP (568)
games currently in development
News: Read the Java Gaming Resources, or peek at the official Java tutorials
 
    Home     Help   Search   Login   Register   
Pages: [1]
  ignore  |  Print  
  Picking again :)  (Read 935 times)
0 Members and 1 Guest are viewing this topic.
Online kevglass

JGO Kernel


Medals: 172
Projects: 23
Exp: 18 years


Coder, Trainee Pixel Artist, Game Reviewer


« Posted 2003-12-23 17:14:55 »

Just trying some picking using the simple GL mechanism. I'm finding I don't always get all the nodes reported on large areas.. is there some resolution restriction I'm not aware of?

Kev

Offline Yuri Vl. Gushchin

Senior Member




Speak Java!


« Reply #1 - Posted 2003-12-23 18:38:53 »

Due to Linux compatibility issues, back-sided faces are not picked (picking back-sided faces causes picking to stop working on some DRI-based drivers, at least CLE266).

Also all the geometry is a subject for frustum and other cullings, so if your geometry has been culled, it definitely will not be picked.

Yuri

Yuri Vl. Gushchin
JProof Group
Online kevglass

JGO Kernel


Medals: 172
Projects: 23
Exp: 18 years


Coder, Trainee Pixel Artist, Game Reviewer


« Reply #2 - Posted 2003-12-23 19:06:44 »

I don't really understand the GL_SELECT thing (although I'm going to go and read about it). Does the current Xith impl re-render the section of the screen specified and records any nodes rendered?

If so, does it adjust the FOV to match what would have been visible on the screen? I'm still getting odd results for what I'd expect to Just Work (tm)

Kev

Games published by our own members! Check 'em out!
Legends of Yore - The Casual Retro Roguelike
Offline Yuri Vl. Gushchin

Senior Member




Speak Java!


« Reply #3 - Posted 2003-12-24 12:17:35 »

From OpenGL docs:

Quote
Selection mode. No pixel fragments are produced, and no change to the framebuffer contents is made. Instead, a record of the names of primitives that would have been drawn if the render mode was GL_RENDER is returned in a select buffer, which must be created  before selection mode is entered


Actually, it first adjusts the FOV/View Frustum to the same used for normal rendering, and then narrowing it to the selection spot (not ray!). If you will just replace GL_SELECT with GL_RENDER, you will see your scene zoomed out to the full GL context area, so the picking spot will occupy all the window. All the objects that will be visible in this window, will pass selection test (even if they are occluded).

Software frustum culling performed using original frustum (the same as one used for rendering).

Yuri

Yuri Vl. Gushchin
JProof Group
Pages: [1]
  ignore  |  Print  
 
 
You cannot reply to this message, because it is very, very old.

 

Add your game by posting it in the WIP section,
or publish it in Showcase.

The first screenshot will be displayed as a thumbnail.

Pippogeek (40 views)
2014-09-24 16:13:29

Pippogeek (31 views)
2014-09-24 16:12:22

Pippogeek (21 views)
2014-09-24 16:12:06

Grunnt (47 views)
2014-09-23 14:38:19

radar3301 (29 views)
2014-09-21 23:33:17

BurntPizza (65 views)
2014-09-21 02:42:18

BurntPizza (37 views)
2014-09-21 01:30:30

moogie (43 views)
2014-09-21 00:26:15

UprightPath (53 views)
2014-09-20 20:14:06

BurntPizza (55 views)
2014-09-19 03:14:18
List of Learning Resources
by Longor1996
2014-08-16 10:40:00

List of Learning Resources
by SilverTiger
2014-08-05 19:33:27

Resources for WIP games
by CogWheelz
2014-08-01 16:20:17

Resources for WIP games
by CogWheelz
2014-08-01 16:19:50

List of Learning Resources
by SilverTiger
2014-07-31 16:29:50

List of Learning Resources
by SilverTiger
2014-07-31 16:26:06

List of Learning Resources
by SilverTiger
2014-07-31 11:54:12

HotSpot Options
by dleskov
2014-07-08 01:59:08
java-gaming.org is not responsible for the content posted by its members, including references to external websites, and other references that may or may not have a relation with our primarily gaming and game production oriented community. inquiries and complaints can be sent via email to the info‑account of the company managing the website of java‑gaming.org
Powered by MySQL Powered by PHP Powered by SMF 1.1.18 | SMF © 2013, Simple Machines | Managed by Enhanced Four Valid XHTML 1.0! Valid CSS!