Convert Sprite to Mesh

BlitzMax Forums/MiniB3D Module/Convert Sprite to Mesh

Kittomer (Posted 2012) [#1]

Just a quick question: Is it somehow possible to convert a TSprite into a TMesh? I tried Addmesh and casting (haha), but while it produced no errors nothing seemed to happen, either. I'm asking this since right now I'm creating grass in my game by the way of sprites and it would be dapper if I could merge them all into a single mesh so that I only have to expend one drawcall on it. I could swear to remember that MiniB3D does some singlesurface stuff with sprites, but considering how much framerate suffers when I have a moderate amount of grass sprites in my scene, I tend not to believe that. If there is no easy way to do that, I guess I will have to put the mesh together manually, not like I don't know how that works. I would prefer the easy way, though.

AdamRedwoods (Posted 2012) [#2]

Tell you what... Here's my TBatchSprite for monkey+minib3d, but you'll have to convert it to BlitzMax yourself. If you do, please repost it so others can benefit. I was going to do this afterwards, as I have several methods of speeding up BMax minib3d. Conversion Notes: - has no Copy() method, instead use CreateSprite() - you'll have to convert over monkey-specific classes like IntStack - make sure the batchorigin is not the came as the camera (0,0,0). i may have to add a check in here for this. '' TBatchSprites '' '' these batchsprites are one mesh '' Class TBatchSpriteMesh Extends TMesh Field surf:TSurface Field free_stack:IntStack ''list of available vertex Field num_sprites =0 Field sprite_list:List<TBatchSprite> Function Create:TBatchSpriteMesh(parent_ent:TEntity=Null) Local mesh:TBatchSpriteMesh = New TBatchSpriteMesh mesh.AddParent(parent_ent) entity_list.EntityListAdd(mesh) ' update matrix If mesh.parent<>Null mesh.mat.Overwrite(mesh.parent.mat) mesh.UpdateMat() Else mesh.UpdateMat(True) Endif mesh.surf = mesh.CreateSurface() mesh.num_sprites = 0 mesh.free_stack = New IntStack 'mainlist mesh.EntityFX 1+2'+1'+32 '' full bright+ use vertex colors + alpha mesh.brush.shine=0.0 'mesh.EntityBlend 3 'mesh.EntityColor(0,0,0) 'mesh.EntityAlpha 0.001 mesh.classname = "BatchSpriteMesh" mesh.is_sprite = True ''may not need this mesh.cull_radius = -999999.0 mesh.sprite_list = New List<TBatchSprite> Return mesh End Method Update(cam:TCamera) mat_sp = mat TBatchSprite.min_x=999999999.0 TBatchSprite.max_x=-999999999.0 TBatchSprite.min_y=999999999.0 TBatchSprite.max_y=-999999999.0 TBatchSprite.min_z=999999999.0 TBatchSprite.max_z=-999999999.0 For Local ent:TEntity = Eachin sprite_list ent.Update(cam) Next ''do our own bounds If num_sprites>0 Local width#=TBatchSprite.max_x-TBatchSprite.min_x Local height#=TBatchSprite.max_y-TBatchSprite.min_y Local depth#=TBatchSprite.max_z-TBatchSprite.min_z ' get bounding sphere (cull_radius#) from AABB ' only get cull radius (auto cull), if cull radius hasn't been set to a negative no. by TEntity.MeshCullRadius (manual cull) If width>=height And width>=depth cull_radius=width Else If height>=width And height>=depth cull_radius=height Else cull_radius=depth Endif Endif cull_radius=cull_radius * 0.5 Local crs#=cull_radius*cull_radius cull_radius= Sqrt(crs+crs+crs) min_x = TBatchSprite.min_x min_y = TBatchSprite.min_y min_z = TBatchSprite.min_z max_x = TBatchSprite.max_x max_y = TBatchSprite.max_y max_z = TBatchSprite.max_z 'mat.grid[3][0] = 1.0'width *0.5 'mat.grid[3][1] = 0'height *0.5 'mat.grid[3][2] = -10.0'-depth *0.5 'PositionEntity(width *0.5,height *0.5,depth *0.5) Endif End End Class TBatchSprite Extends TSprite Field batch_id:Int ''ids start at 1 Field vertex_id:Int Field sprite_link:list.Node<TBatchSprite> Global min_x:Float, min_y:Float, max_x:Float, max_y:Float, min_z:Float, max_z:Float Global mainsprite:TBatchSpriteMesh[] = New TBatchSpriteMesh[10] Global total_batch:Int =0 Private Global temp_mat:Matrix = New Matrix Public Method New() ''new batch sprite End Method FreeEntity() 'Print"spritebatch remove" mainsprite[batch_id].surf.VertexColor(vertex_id+0, 0,0,0,0) mainsprite[batch_id].surf.VertexColor(vertex_id+1, 0,0,0,0) mainsprite[batch_id].surf.VertexColor(vertex_id+2, 0,0,0,0) mainsprite[batch_id].surf.VertexColor(vertex_id+3, 0,0,0,0) 'mainsprite[batch_id].surf.reset_vbo = mainsprite[batch_id].surf.reset_vbo|8 mainsprite[batch_id].free_stack.Push(vertex_id) sprite_link.Remove() If parent parent_link.Remove() parent=Null Endif mat=Null brush=Null link=Null End Method Copy() ''use CreateSprite(), since they should all be the same End '' ''add a parent to the entire batch mesh '' Function BatchSpriteParent(id:Int=0, ent:TEntity,glob:Int=True) If id=0 Then id = total_batch If id = 0 Then Return mainsprite[id].EntityParent(ent, glob) End '' ''return the sprite batch main mesh entity '' Method BatchSpriteEntity:TEntity() Return mainsprite[batch_id] End '' ''move the batch sprite origin for depth sorting '' Method BatchSpriteOrigin(x:Float,y:Float,z:Float) mainsprite[batch_id].PositionEntity(x,y,z) End Function CreateBatchMesh:TBatchSpriteMesh( batchid:Int ) While total_batch < batchid Or total_batch =0 total_batch +=1 If total_batch >= mainsprite.Length() Then mainsprite = mainsprite.Resize(total_batch+5) 'Print "TBatchSPrite createmesh:"+total_batch 'Print mainsprite.Length() mainsprite[total_batch] = TBatchSpriteMesh.Create() Wend Return mainsprite[total_batch] End Function CreateSprite:TBatchSprite(idx:Int=0) ''add sprite to batch Local sprite:TBatchSprite=New TBatchSprite sprite.classname="BatchSprite" ' update matrix If sprite.parent<>Null sprite.mat.Overwrite(sprite.parent.mat) sprite.UpdateMat() Else sprite.UpdateMat(True) Endif If idx = 0 Then sprite.batch_id = total_batch Else sprite.batch_id = idx If sprite.batch_id = 0 Then sprite.batch_id = 1 Local id:Int = sprite.batch_id ''create main mesh Local mesh:TBatchSpriteMesh If id > total_batch mesh = CreateBatchMesh(id) If id=0 Then id = 1 Else mesh = mainsprite[id] Endif ''get vertex id Local v:Int If mesh.free_stack.IsEmpty() mesh.num_sprites +=1 v = (mesh.num_sprites-1) * 4 ''4 vertex per quad 'Local p:Int = v+1 mesh.surf.AddVertex(-1,-1,0, 0, 1) mesh.surf.AddVertex(-1, 1,0, 0, 0) mesh.surf.AddVertex( 1, 1,0, 1, 0) mesh.surf.AddVertex( 1,-1,0, 1, 1) mesh.surf.AddTriangle(0+v,1+v,2+v) mesh.surf.AddTriangle(0+v,2+v,3+v) 'Print "TSPrite verts:"+mesh.surf.no_verts+":" Else v = mesh.free_stack.Pop() Endif mesh.reset_bounds = False ''we control our own bounds sprite.vertex_id = v 'sprite.EntityParent(mainsprite[batchid],0) ''add to child list 'sprite.parent = Null ''but dont use the parent matrix sprite.sprite_link = mesh.sprite_list.AddLast(sprite) Return sprite End Function LoadBatchTexture(tex_file$,tex_flag:Int=1,id:Int=0) '' ''does not create sprite, just loads texture '' If id<=0 Or id>total_batch Then id=total_batch If id=0 Then id=1 CreateBatchMesh(id) Local tex:TTexture=TTexture.LoadTexture(tex_file,tex_flag) mainsprite[id].EntityTexture(tex) ' additive blend if sprite doesn't have alpha or masking flags set If tex_flag&2=0 And tex_flag&4=0 mainsprite[id].EntityBlend 3 'tex.TextureBlend 3 Endif End Method Update(cam:TCamera ) If view_mode<>2 '' add in mainsprite position offset Local x#=mat.grid[3][0] - mainsprite[batch_id].mat.grid[3][0] Local y#=mat.grid[3][1] - mainsprite[batch_id].mat.grid[3][1] Local z#=mat.grid[3][2] - mainsprite[batch_id].mat.grid[3][2] temp_mat.Overwrite(cam.mat) temp_mat.grid[3][0]=x temp_mat.grid[3][1]=y temp_mat.grid[3][2]=z mat_sp.Overwrite(temp_mat) If angle<>0.0 mat_sp.RotateRoll(angle) Endif If scale_x<>1.0 Or scale_y<>1.0 mat_sp.Scale(scale_x,scale_y,1.0) Endif If handle_x<>0.0 Or handle_y<>0.0 mat_sp.Translate(-handle_x,-handle_y,0.0) Endif Else mat_sp.Overwrite(mat) If scale_x<>1.0 Or scale_y<>1.0 mat_sp.Scale(scale_x,scale_y,1.0) Endif Endif ''update main mesh '' rotate each point corner offset to face the camera with cam_mat '' use the mat.x.y.z for position and offset from that Local p0:Float[], p1:Float[], p2:Float[], p3:Float[] 'Local temp_mat:Matrix = mat_sp.Copy() 'Inverse() Local o:Float[] = [mat_sp.grid[3][0],mat_sp.grid[3][1],mat_sp.grid[3][2]] Local m00:Float = mat_sp.grid[0][0] Local m01:Float = mat_sp.grid[0][1] Local m10:Float = mat_sp.grid[1][0] Local m11:Float = mat_sp.grid[1][1] Local m02:Float = mat_sp.grid[0][2] Local m12:Float = mat_sp.grid[1][2] 'p0 = mat_sp.TransformPoint(-1.0,-1.0,0.0) p0 = [-m00 + -m10 + o[0] , -m01 + -m11 + o[1], m02 + m12 - o[2]] 'p1 = mat_sp.TransformPoint(-1.0,1.0,0.0) p1 = [-m00 + m10 + o[0] , -m01 + m11 + o[1], m02 - m12 - o[2]] 'p2 = mat_sp.TransformPoint(1.0,1.0,0.0) p2 = [m00 + m10 + o[0] , m01 + m11 + o[1], -m02 - m12 - o[2]] 'p3 = mat_sp.TransformPoint(1.0,-1.0,0.0) p3 = [m00 - m10 + o[0] , m01 - m11 + o[1], -m02 + m12 - o[2]] mainsprite[batch_id].surf.VertexCoords(vertex_id+0,p0[0],p0[1],p0[2]) mainsprite[batch_id].surf.VertexCoords(vertex_id+1,p1[0],p1[1],p1[2]) mainsprite[batch_id].surf.VertexCoords(vertex_id+2,p2[0],p2[1],p2[2]) mainsprite[batch_id].surf.VertexCoords(vertex_id+3,p3[0],p3[1],p3[2]) Local r# = brush.red'*brush.alpha Local g# = brush.green'*brush.alpha Local b# = brush.blue'*brush.alpha Local a# = brush.alpha '*0.5 mainsprite[batch_id].surf.VertexColorFloat(vertex_id+0, r,g,b,a) mainsprite[batch_id].surf.VertexColorFloat(vertex_id+1, r,g,b,a) mainsprite[batch_id].surf.VertexColorFloat(vertex_id+2, r,g,b,a) mainsprite[batch_id].surf.VertexColorFloat(vertex_id+3, r,g,b,a) ''determine our own bounds min_x = Min5(p0[0],p1[0],p2[0],p3[0],min_x ) min_y = Min5(p0[1],p1[1],p2[1],p3[1],min_y ) min_z = Min5(p0[2],p1[2],p2[2],p3[2],min_z ) max_x = Max5(p0[0],p1[0],p2[0],p3[0],max_x ) max_y = Max5(p0[1],p1[1],p2[1],p3[1],max_y ) max_z = Max5(p0[2],p1[2],p2[2],p3[2],max_z ) End End Function Min5:Float(a:Float, b:Float, c:Float, d:Float, e:Float) Local r:Float = a Local t:Float = c If b<r Then r=b If d<t Then t=d If t<r Then r=t If r < e Then Return r Else Return e End Function Max5:Float(a:Float, b:Float, c:Float, d:Float, e:Float) Local r:Float = a Local t:Float = c If b>r Then r=b If d>t Then t=d If t>r Then r=t If r > e Then Return r Else Return e End Other thoughts re: Grass sprites .... so when rendering sprites as one mesh, you lose alpha depth sorting (order independent depth sorting anyone? bleh). Therefore, you would have to use Alpha testing mask (but no alpha), which means you'll get fringe artifacts on your transparent pngs. Or you could just render the mesh first (set origin far away from camera) and handle cases where grass overlaps transparent objects (ie. glass cylinder in open fields, will render over the grass if the grass batch sprite is transparent) Last edited 2012

Kittomer (Posted 2012) [#3]

Thanks, I'll look into it! Although I'm not sure I need something quite that comprehensive. Also I know nothing about monkey. Being on the subject, how likely is it that my code will just... work if I'd just copy it into monkey, if I don't use anything except standard blitzmax and minib3d code?

AdamRedwoods (Posted 2012) [#4]

re: copying into monkey from blitz to monkey, you might do ok, but i would also hesitate and say no, monkey has too many 'gotchas' that will require some thinking if portability is a requirement.

Kittomer (Posted 2012) [#5]

Converting that code was a bit above my head, so I ended up adapting my chunk meshing code to build a single grass mesh. Is a lot faster now.