RE: [Algorithms] Texture mapping, Weighted Vertex Normals and Oct ree Nodes

 RE: [Algorithms] Texture mapping, Weighted Vertex Normals and Oct ree Nodes From: Mitch Walker - 2001-01-30 17:47:05 ```Octree Nodes: You will want to use a bounding volume rather than the center of the object to determine what node(s) it is in. You can either include it in all of the nodes that it intersects, but be sure to only render it once. You can push it up to the parent that owns all of the nodes it intersects, or you could use "loose" octrees to tweak the node to completely encompass the object. See Game Programming Gems for an article on loose octrees. HTH, Mitch -----Original Message----- From: Chris Brodie [mailto:Chris.Brodie@...] Sent: Sunday, January 28, 2001 8:07 PM To: 'gdalgorithms-list@...' Subject: [Algorithms] Texture mapping, Weighted Vertex Normals and Octree Nodes 3 Questions: Texture Mapping: Just say I have a stone. The stone is roughly spherical(convex). I have a texture that has been made tileable and would like to wrap the stone in the texture without seams. This concept seems quite difficult for me without the use of some bizzare shape dependent use of spherical mapping and modifying the texture. How does one do this? Weighted Vertex Normal: I tried the technique that was posted a few days ago (the whole code sample) however I seem to have a strange artifact on the screen now. Organic shapes seem to have slight highlights along their edges. I noticed a few posts about calculating angles and area, could I get more information on that? How does the area relate to the normal weight? Are there any example around you guys know of? Octree Nodes: When placing object in to an octree how do I handle cases where the object(say a car) is perfectly centrered at 0,0,0 or in face any edge or junction of cubes. It seems to that the object will inhabit a neighbouring node but not be linked from there. Why ask? Well if a large object say an aircraft carrier's centre lived in a node that wasn't in view but the nose was it wouldn't get drawn. I think I've missed the point somewhere. Hopefully the answer isn't clip at octree boundries... Many thanks Chris ```

 RE: [Algorithms] Texture mapping, Weighted Vertex Normals and Oct ree Nodes From: Mitch Walker - 2001-01-30 17:47:05 ```Octree Nodes: You will want to use a bounding volume rather than the center of the object to determine what node(s) it is in. You can either include it in all of the nodes that it intersects, but be sure to only render it once. You can push it up to the parent that owns all of the nodes it intersects, or you could use "loose" octrees to tweak the node to completely encompass the object. See Game Programming Gems for an article on loose octrees. HTH, Mitch -----Original Message----- From: Chris Brodie [mailto:Chris.Brodie@...] Sent: Sunday, January 28, 2001 8:07 PM To: 'gdalgorithms-list@...' Subject: [Algorithms] Texture mapping, Weighted Vertex Normals and Octree Nodes 3 Questions: Texture Mapping: Just say I have a stone. The stone is roughly spherical(convex). I have a texture that has been made tileable and would like to wrap the stone in the texture without seams. This concept seems quite difficult for me without the use of some bizzare shape dependent use of spherical mapping and modifying the texture. How does one do this? Weighted Vertex Normal: I tried the technique that was posted a few days ago (the whole code sample) however I seem to have a strange artifact on the screen now. Organic shapes seem to have slight highlights along their edges. I noticed a few posts about calculating angles and area, could I get more information on that? How does the area relate to the normal weight? Are there any example around you guys know of? Octree Nodes: When placing object in to an octree how do I handle cases where the object(say a car) is perfectly centrered at 0,0,0 or in face any edge or junction of cubes. It seems to that the object will inhabit a neighbouring node but not be linked from there. Why ask? Well if a large object say an aircraft carrier's centre lived in a node that wasn't in view but the nose was it wouldn't get drawn. I think I've missed the point somewhere. Hopefully the answer isn't clip at octree boundries... Many thanks Chris ```
 [Algorithms] Flexporter news From: Pierre Terdiman - 2001-01-31 21:59:19 ```- new version 1.07 - little mailing list opened http://www.codercorner.com/Flexporter.htm Pierre ```
 Re: [Algorithms] Flexporter news From: Pierre Terdiman - 2001-02-04 00:03:55 ```Ok, gimme a break! - new version 1.08 - supports MAX 4 and Character Studio 3 Pierre Terdiman * Home: p.terdiman@... Coder in the dark * Zappy's Lair: http://www.codercorner.com ----- Original Message ----- From: Pierre Terdiman To: Sent: Wednesday, January 31, 2001 10:52 PM Subject: [Algorithms] Flexporter news > - new version 1.07 > - little mailing list opened > > http://www.codercorner.com/Flexporter.htm > > Pierre > > > _______________________________________________ > GDAlgorithms-list mailing list > GDAlgorithms-list@... > http://lists.sourceforge.net/lists/listinfo/gdalgorithms-list ```
 [Algorithms] Motion blending From: Pierre Terdiman - 2001-02-05 09:25:05 ```Two questions about motion blending in skeletal animation: - First, a basic one about the correct terminology. I've always used the words "motion blending" to describe the smooth transitions between one motion to another. But then, for some people it seems to be related to mixing one part of a motion (say a run) with one part of another (say raising the arm). So, motion blending = what? And how is called "the other one" in correct character-parlance, hmmm? - Second, an authoring question. How do you edit the transitions between motions? Do people usually rely on a custom editor to do this? Is there a way to edit this in MAX - or another package? In my last engine I've spent some time hardcoding those things, and I don't want to do this again!! (Just for fun, here's how it looked for *one* transition. trc.Name = "StopToJumpRun1"; trc.TargetMotionCell = JumpRun1Cell; trc.BlendDuration = 10; trc.SourceBaseFrame = 0; trc.TargetBaseFrame = 0; trc.TimeBlendData.MappingType = TBLEND_LINEAR; trc.Activation = BLEND_DIRECT; trc.Event.NbBasicEvents = 1; trc.Event.BasicEvent[0].ID = EVENT_JOYSTICK; trc.Event.BasicEvent[0].Param.d = JOYSTICK_BUTTON1; trc.Event.BasicEvent[0].AllowedDelay = PFX_MAX_FLOAT; trc.MotionInterval.StartFrame = 0; trc.MotionInterval.EndFrame = PFX_MAX_SDWORD; trc.ValidityInterval.StartFrame = 0; trc.ValidityInterval.EndFrame = PFX_MAX_SDWORD; trc.CallBack = Jumping2; StopCell->TransitionCreate(trc); That again? No way!) Pierre Terdiman * Home: p.terdiman@... Coder in the dark * Zappy's Lair: http://www.codercorner.com ```
 [Algorithms] Plane equations From: Klaus Hartmann - 2001-02-05 17:11:18 ```Hi all! I'm using planes all the time and they work well for me, but if I'm honest then I have to admit that I don't fully understand the plane equation Ax+By+Cz+D=0. I've looked in all sorts of places for a good explanation (including math books), but I wasn't able to find anything that really helps me. Maybe someone can shed some light into it. Here's what I *believe* I understand so far. A plane is defined by the infinite set of points P(x, y, z) that satisfy the condition Ax+By+Cz+D=0 (that is a plane is defined by the set of points that lie on the plane). The coefficients A, B, and C are the components of the vector normal to the plane, N = (A B C), and D is some constant. This constant D seems to be the distance from the origin to the plane, if and only if the normal vector N is a unit vector. I also know that I can rewrite the above plane equation as (N _dot_ P) + D = 0. This is obvious, and I can use this information to classify a point (determine in which half-space it is) or to calculate the signed distance from the plane to the point (if the normal vector N is a unit vector). My question: "Why? Why does the above work the way it works?". I believe my biggest problem here is that I have trouble to understand the true meaning of the constant D. Hope someone can help. Niki ```