Kinda like this?
Graphics3D 640,480,32,2 SetBuffer BackBuffer() CreateLight() Global Camera = CreateCamera() PositionEntity Camera,0,2,-6 CameraRange Camera,.1,100 Global TextureAlpha = CreateTexture(512,512,1+2) SetBuffer TextureBuffer(TextureAlpha) For wx = 0 To 511 For wy = 0 To 511 WritePixel(wx,wy,0) ; not sure how to use the argb input, but any value seems to make it transparent for me (0-255) Next Next Color 255,255,255 Rect 128,128,256,256 Color 255,0,0 For c = 0 To 22;<Thickness Rect c,c,512-(c*2),512-(c*2),0 Next SetBuffer BackBuffer() Global TextureMasked = CreateTexture(512,512,1+4) SetBuffer TextureBuffer(TextureMasked) For wx = 0 To 511 For wy = 0 To 511 WritePixel(wx,wy,0) ; not sure how to use the argb input, but any value seems to make it transparent for me (0-255) Next Next Color 255,255,255 Rect 128,128,256,256 Color 255,0,0 For c = 0 To 22;<Thickness Rect c,c,512-(c*2),512-(c*2),0 Next SetBuffer BackBuffer() Global Ground = CreatePlane() EntityColor Ground,128,64,0 Global Cube1 = CreateCube() PositionEntity Cube1,1.5,1.1,1 EntityTexture Cube1,TextureAlpha EntityFX Cube1,16 Global Cube2 = CreateCube() PositionEntity Cube2,-1.5,1.1,1 EntityTexture Cube2,TextureMasked EntityFX Cube2,16 While Not KeyDown(1) TranslateEntity Camera,(KeyDown(205)-KeyDown(203))*.1,(KeyDown(200)-KeyDown(208))*.1,(KeyDown(30)-KeyDown(44))*.1 UpdateWorld RenderWorld Color 255,255,255 Text 0,0,"Arrow Keys to move up, down, left, right" Text 0,20,"A and Z to move forward and backward" Color 0,255,255 CameraProject Camera,EntityX(Cube1),EntityY(Cube1),EntityZ(Cube1) Text ProjectedX(),ProjectedY()-80,"Alpha texture",1,1 CameraProject Camera,EntityX(Cube2),EntityY(Cube2),EntityZ(Cube2) Text ProjectedX(),ProjectedY()-80,"Masked texture",1,1 Flip Wend End