many objects in one level/zones?
Blitz3D Forums/Blitz3D Programming/many objects in one level/zones?
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| What methods are recommended for using many objects in one level ? I tried several methods allready: collapsing everything into one object with AddMesh and using CopyEntity instead of loading the same mesh over and over again. I remember a code in the archives that stores only the object's coordinates and creates new meshes 'on the fly' when the camera gets in a certain range. Unf. I cannot find it anymore. But would that be a better method? Here and there I've heard the term 'zones' in this context. What are zones ? Are they 'clusters' of meshes that are hidden/showed when the camera gets near ? What is the idea behind that ? Thanks for any suggestions. |
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| ..maybe this can help.. ; Definit le Frustum Global p1x,p1y Global p2x,p2y ; Enfants du Quadtree Const CHILD00 = 0 Const CHILD01 = 1 Const CHILD11 = 2 Const CHILD10 = 3 ; CAMERA Type CAMERA Field x,y ; Position de la camera Field fov ; Angle de vue End Type ; creation d'une camera Function Camera.CAMERA(x,y,fov) this.CAMERA = New CAMERA this\x = x : this\y = y : this\fov = fov Return this End Function ; Renvoie True si un point est dans le plan Left du Frustum Function PointInFrustumL(this.CAMERA,x,y) Return ( -(x - this\x) * (p1y - this\y) + (y - this\y) * (p1x - this\x) >= 0) End Function ; Renvoie True si un point est dans le plan Right du Frustum Function PointInFrustumR(this.CAMERA,x,y) Return ( -(x - this\x) * (p2y - this\y) + (y - this\y) * (p2x - this\x) <= 0) End Function ; Renvoie True si un point est dans le plan Front du Frustum (pas utilisé ici) Function PointInFrustumF(this.CAMERA,x,y) Return ( -(x - this\x) * (p3y - this\y) + (y - this\y) * (p3x - this\x) >= 0) End Function ; QUADTREE Type QUADTREE Field Child.QUADTREE[3] ; Les 4 enfants du quadtree Field xmin,ymin ; Coordonnées du sommet haut gauche Field xmax,ymax ; Coordonnées du sommet bas droite End Type ; Creation d'un quadtree de profondeur depth ; et associé à un carré de cotés xmax-xmin, ymax-ymin Function Quadtree.QUADTREE(xmin,ymin,xmax,ymax,depth) this.QUADTREE = New QUADTREE this\xmin = xmin this\xmax = xmax this\ymin = ymin this\ymax = ymax If (depth > 0) ; On crée 4 enfants xmoy = (xmin+xmax) / 2 ymoy = (ymin+ymax) / 2 depth = depth - 1 this\Child[CHILD00] = Quadtree(xmin,ymin,xmoy,ymoy,depth) ; Haut gauche this\Child[CHILD01] = Quadtree(xmin,ymoy,xmoy,ymax,depth) ; Bas gauche this\Child[CHILD11] = Quadtree(xmoy,ymoy,xmax,ymax,depth) ; Bas droite this\Child[CHILD10] = Quadtree(xmoy,ymin,xmax,ymoy,depth) ; Haut droite EndIf Return this End Function ; On teste si un des 4 sommets du carré associé au quadtree ; est visible par la camera Function QuadInFrustum(this.QUADTREE,cam.CAMERA) Local nbPlansInterieur ; Plan de gauche nbPlansInterieur = 0 nbPlansInterieur = nbPlansInterieur + PointInFrustumL(cam,this\xmin,this\ymin) nbPlansInterieur = nbPlansInterieur + PointInFrustumL(cam,this\xmin,this\ymax) nbPlansInterieur = nbPlansInterieur + PointInFrustumL(cam,this\xmax,this\ymin) nbPlansInterieur = nbPlansInterieur + PointInFrustumL(cam,this\xmax,this\ymax) If nbPlansInterieur = 0 Return False ; Plan de droite nbPlansInterieur = 0 nbPlansInterieur = nbPlansInterieur + PointInFrustumR(cam,this\xmin,this\ymin) nbPlansInterieur = nbPlansInterieur + PointInFrustumR(cam,this\xmin,this\ymax) nbPlansInterieur = nbPlansInterieur + PointInFrustumR(cam,this\xmax,this\ymin) nbPlansInterieur = nbPlansInterieur + PointInFrustumR(cam,this\xmax,this\ymax) If nbPlansInterieur = 0 Return False Return True End Function ; Rendu du Quadtree Function RenderQuadtree(this.QUADTREE,cam.CAMERA,depth) If QuadInFrustum(this,cam) If (depth > 1) Color 128,128,128 Line (this\xmin+this\xmax)/2,this\ymin,(this\xmin+this\xmax)/2,this\ymax Line this\xmin,(this\ymin+this\ymax)/2,this\xmax,(this\ymin+this\ymax)/2 depth = depth - 1 RenderQuadtree(this\Child[CHILD00],cam,depth) RenderQuadtree(this\Child[CHILD01],cam,depth) RenderQuadtree(this\Child[CHILD11],cam,depth) RenderQuadtree(this\Child[CHILD10],cam,depth) Else Color 196,196,196 Rect this\xmin+1,this\ymin+1,this\xmax-this\xmin-1,this\ymax-this\ymin-1,True EndIf EndIf End Function ;============================================================================================== ; EXAMPLE ;============================================================================================== AppTitle "Simple Quadtree Demo - Seyhajin" Graphics 512,512,0,2 SetBuffer BackBuffer() ; Variables de configuration QuadDepth = 7 ; Profondeur du quadtree (nb de fois qu'on decoupe le plan) QuadSize = 512 ; Taille initiale du quadtree CamSpeed# = 2 ; Vitesse de deplacement de la camera CamFOV# = 60.0 / 2.0 ; Angle de vue de la camera (default = 90) ViewLine = 300 ; Taille de la ligne des plans ; Creation de la camera cam.CAMERA = Camera(QuadSize/2,QuadSize/2,CamFOV) ; Creation du Quadtree principale root.QUADTREE = Quadtree(0,0,QuadSize,QuadSize,QuadDepth) ;---------------------------------- ; BOUCLE PRINCIPALE ;---------------------------------- While Not KeyHit(1) Cls ; Update Camera position If KeyDown(200) ; Up cam\y = cam\y - CamSpeed# ElseIf KeyDown(208) ; Down cam\y = cam\y + CamSpeed# EndIf If KeyDown(203) ; Left cam\x = cam\x - CamSpeed# ElseIf KeyDown(205) ; Right cam\x = cam\x + CamSpeed# EndIf ; Rendu du quadtree Color 255,255,255 Rect root\xmin,root\ymin,root\xmax,root\ymax,1 RenderQuadtree(root,cam,QuadDepth) ; Dessine la pyramide de vue (Frustum) x# = MouseX() - cam\x y# = MouseY() - cam\y angle# = 180+ATan2(-y#,-x#) Color 255,255,0 Line cam\x,cam\y,cam\x+(ViewLine/2)*Cos(angle#),cam\y+(ViewLine/2)*Sin(angle#) Color 255,0,0 ; Plan gauche p1x = cam\x+ViewLine*Cos(angle#-CamFOV) p1y = cam\y+ViewLine*Sin(angle#-CamFOV) Line cam\x,cam\y,p1x,p1y ; Plan droit p2x = cam\x+ViewLine*Cos(angle#+CamFOV) p2y = cam\y+ViewLine*Sin(angle#+CamFOV) Line cam\x,cam\y,p2x,p2y ; Dessine la camera Color 0,0,255 Oval cam\x-3,cam\y-3,6,6,True Flip Wend Delete Each CAMERA Delete Each QUADTREE |
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| Thanks for the example. In a way, I understand what it does. But should I hide entites that are not in view? |
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| use Entity Auto Fade |
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| But should I hide entites that are not in view? use o_OEntity Auto Fade Don't do anything. Blitz automatically doesn't render stuff that isn't in view. |
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| Some infos: Blitz can only "hide" things that are (A) behind the camera or (B) out of the camera range IF they are individual entities. This means, if you have a big level that is loaded as one mesh and has say 20k triangles, then Blitz will always render 20k Triangles, no matter if you only watch a single wall or have a very low camera range. So it may be important to cut the level in pieces. (See ClusterizeMesh in the archives) While the fragmentation of a big level mesh may feel a little tricky, additional meshes in the scene will be hidden automaticly and efficiently, as long as they don't cover wide areas. Example: trees: not every tree should be an entity, nor should you add all trees to a single mesh. The golden middle way would be to add groups of trees to a grid of meshes using a polycount that makes sense. If it's an indoor level then it's even easier, make sure the various level places are connected by fairly long tunnel systems, so you'll never render more than one place. There are more systems to cull things and "optimize" the speed. VIS-Zones is one. BSP VIS Occlusion and more. A lot of people tried many things and there's a good chance that if you implement one of these complicated culling techniques then it will be slower than the unculled counterpart at the end of the day, so KISS, keep it simple. If you use fragmentation and a low camera range then the speed is ok. All you have to do is to design the level with a low camerarange in mind. |
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| Thanks a lot |
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