Is this useful for anything?

Blitz3D Forums/Blitz3D Programming/Is this useful for anything?

big10p (Posted 2005) [#1]

Came across this old demo on my HD. It basically finds where a line intersects with a box. The box can have any rotation/size and doesn't need to be axis-aligned. It doesn't use LinePick and the distance between object and target doesn't affect speed - I don't think so, anyway. :P Graphics3D 800,600,32 SetBuffer BackBuffer() WireFrame 0 AntiAlias 0 SeedRnd MilliSecs() Global frame_count% Global fps% Global slowest_fps% Global fps_timeout% Global frame_time% Global slowest_frame% Global frame_start% fps_timer = CreateTimer(60) slowmo% = False wiref% = False piv = CreatePivot() cam = CreateCamera(piv) PositionEntity cam,0,0,-8 TurnEntity piv,0,45,0 light = CreateLight() cube = CreateCube() EntityAlpha cube,.9 ;PositionEntity cube,-.5,-2,3 xsize# = .5 ysize# = 1.23 zsize# = 1.5 ScaleMesh cube,xsize,ysize,zsize piv2 = CreatePivot() enemy = CreateCone(32,1,piv2) RotateMesh enemy,90,0,0 UpdateNormals enemy ScaleEntity enemy,.3,.3,.3 PositionEntity enemy,1,2,-3 EntityColor enemy,255,255,0 hit = CreateSphere() ScaleMesh hit,.12,.12,.12 EntityColor hit,0,255,0 PositionEntity hit,0,0,0 p#=-.1 y#=-.5 r#=1 p2#=0 y2#=-.5 r2#=-1 timer = MilliSecs() num_spots=100 s=CreateSphere(3,cube) ScaleMesh s,.1,.1,.1 EntityColor s,255,0,255 HideEntity s Dim spots(num_spots) For n=1 To num_spots spots(n)=CopyEntity(s,cube) PositionEntity spots(n),0,10000,0 Next free_spot=1 ; Main loop While Not KeyHit(1) frame_start = MilliSecs() If KeyHit(28) Then slowmo = Not slowmo If KeyHit(14) wiref = Not wiref WireFrame wiref EndIf PointEntity enemy,cube TurnEntity piv2,p2,y2,r2 If MilliSecs()-timer>=3000 p=Rnd(-1,1) y=Rnd(-1,1) r=Rnd(-1,1) p2=Rnd(-1,1) y2=Rnd(-1,1) r2=Rnd(-1,1) timer=MilliSecs() EndIf TurnEntity cube,p,y,r l3d = create_3D_line(0,EntityX(cube,1),EntityY(cube,1),EntityZ(cube,1),EntityX(enemy,1),EntityY(enemy,1),EntityZ(enemy,1),255,0,0) TFormPoint EntityX(enemy,1),EntityY(enemy,1),EntityZ(enemy,1),0,cube dx# = TFormedX() dy# = TFormedY() dz# = TFormedZ() rat1# = xsize/Abs(dx) rat2# = ysize/Abs(dy) rat3# = zsize/Abs(dz) rat# = lowest_val(rat1,rat2,rat3) nx# = rat * dx ny# = rat * dy nz# = rat * dz TFormPoint nx,ny,nz,cube,0 PositionEntity hit,TFormedX(),TFormedY(),TFormedZ(),1 PositionEntity spots(free_spot),nx,ny,nz free_spot=free_spot+1 If free_spot>num_spots Then free_spot=1 CameraClsMode cam,1,1 HideEntity cube HideEntity hit HideEntity enemy ShowEntity l3d WireFrame 1 RenderWorld CameraClsMode cam,0,0 ShowEntity cube ShowEntity hit ShowEntity enemy HideEntity l3d WireFrame 0 RenderWorld frame_time = MilliSecs() - frame_start show_info() WaitTimer(fps_timer) Flip(1) FreeEntity l3d If slowmo Then Delay 200 Wend ClearWorld End Function lowest_val#(v1#,v2#,v3#) If v1<v2 And v1<v3 Return v1 ElseIf v2<v3 Return v2 Else Return v3 EndIf End Function ; ; Display debug info ; Function show_info() If fps_timeout frame_count = frame_count + 1 If MilliSecs() > fps_timeout Then fps_timeout = MilliSecs() + 1000 fps = frame_count frame_count = 0 If fps < slowest_fps Or slowest_fps = 0 Then slowest_fps = fps EndIf If frame_time > slowest_frame Then slowest_frame = frame_time Color 0,255,0 Text 10,10," Triangles: " + TrisRendered() Color 255,255,0 Text 10,25," Millisecs: " + frame_time Text 10,40," Slowest: " + slowest_frame Color 0,255,255 Text 10,55," FPS: " + fps Text 10,70," Worst: " + slowest_fps Color 255,255,255 Else ; First call initialization. fps_timeout = MilliSecs() + 1000 EndIf End Function Function create_3D_line(mesh,x0#,y0#,z0#,x1#,y1#,z1#,r%=255,g%=255,b%=255) If mesh = 0 mesh = CreateMesh() surf = CreateSurface(mesh) EntityFX mesh,1+2+16 Else last_surf = CountSurfaces(mesh) surf = GetSurface(mesh,last_surf) If CountVertices(surf) > 30000 Then surf = CreateSurface(mesh) End If v0 = AddVertex(surf,x0,y0,z0) v1 = AddVertex(surf,x1,y1,z1) v2 = AddVertex(surf,x0,y0,z0) AddTriangle surf,v0,v1,v2 VertexColor surf,v0,r,g,b VertexColor surf,v1,r,g,b VertexColor surf,v2,r,g,b Return mesh End Function I just developed this from a 2D version but didn't have any real use for it. Does it even have any use? :)

jfk EO-11110 (Posted 2005) [#2]

I'm sure it's useful, you should add it to the code archives, algorithm section.

big10p (Posted 2005) [#3]

Hmmm, maybe - I just can't believe that anything I've done that's maths-based is useful and not already common knowledge. :P

Damien Sturdy (Posted 2005) [#4]

..I needed this functionality by last month damnit :P Neat :)

big10p (Posted 2005) [#5]

Really? What for? lol. :P

Damien Sturdy (Posted 2005) [#6]

The car racer- to add car-car collision sounds without having to "meshesintersect". It's pretty much complete, and has all the sounds already, but meshesintersect is slow, so i wanted to update it. The above would let me position a sound too. [edit] I would have used box collision, but it didnt work for some reason- can't remember what though now.