This code shows what I beleive 1:1 texel to pixel rendering in Blitz3D, tested with a 64x64 sprite. Note the EntityPosition offset of -.5,-.5 as documented in dx7 sdk.
; overlay.bb displaywidth=800 displayheight=600 Graphics3D displaywidth,displayheight ClearTextureFilters cam=CreateCamera() CameraClsColor cam,100,120,200 CameraRange cam,.1,1000 overlay=CreatePivot() aspect#=Float(displayheight)/displaywidth PositionEntity overlay,-1,aspect,1 scale#=2.0/displaywidth ScaleEntity overlay,scale,-scale,-scale sp=LoadSprite("simon.bmp") EntityParent sp,overlay ScaleSprite sp,4.0/64,4.0/64 SpriteViewMode sp,2 While Not KeyHit(1) PositionEntity sp,MouseX()-.5,MouseY()-.5,0 RenderWorld UpdateWorld Flip Wend End