Code archives/3D Graphics - Misc/Backdrops in 3D
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| Use this to create a 2D-style backdrop in 3D (drawing 2D-behind-3D apparently slows to a crawl on some cards). It breaks the image down into 256 x 256 (default) textures, and applies them to a grid of sprites. Apart from the positioning, which is screwed up on some images (but can easily be played with for your specific image), this seems to work quite well... besides, I wanted to post the first code of 2002 [Doh! The server's still in 2001!]... | |||||
; ----------------------------------------------------------------------------------- ; Make3DBackdrop () demo... ; ----------------------------------------------------------------------------------- ; 3D backdrop made up of sprites. Why? ; Since some cards will automatically rescale textures down to 256 x 256 or less, ; you shouldn't really try to use one big sprite -- it's also a struggle for many ; cards to deal with screen-sized textures!)... ; The default size used is 256 x 256, as this is what Voodoos seem to scale textures ; down to. Most cards should be OK with this, but you can always load a dummy ; texture of 256 x 256 and check the result with TextureWidth (), then pass ; that value to Make3DBackdrop (see function description). ; ----------------------------------------------------------------------------------- ; Demo... ; ----------------------------------------------------------------------------------- ; If you use an image larger than the screen, the cursors will scroll ; it around... ; ----------------------------------------------------------------------------------- ; W for wireframe... ; ----------------------------------------------------------------------------------- Graphics3D 640, 480 AppTitle "W for wireframe..." cam = CreateCamera () light = CreateLight () MoveEntity light, -10, 10, -10 cube = CreateCube () MoveEntity cube, 0, 0, 5 EntityColor cube, 128, 0, 0 ; ----------------------------------------------------------------------------------- ; Make a 3D backdrop from given image... ; ----------------------------------------------------------------------------------- backdrop = Make3DBackdrop (cam, "G:\My Documents\My Pictures\horsehead nebula.bmp") Repeat TurnEntity cube, 1, 1, 1 TranslateEntity cube, 0, 0, 0.1 If KeyHit (17) w = 1 - w: WireFrame w If KeyDown (203) MoveEntity backdrop, 0.1, 0, 0 Else If KeyDown (205) MoveEntity backdrop, -0.1, 0, 0 EndIf EndIf If KeyDown (200) MoveEntity backdrop, 0, -0.1, 0 Else If KeyDown (208) MoveEntity backdrop, 0, 0.1, 0 EndIf EndIf RenderWorld ; Impose your own movement restrictions based on these...! ;Text 20, 20, EntityX (backdrop) ;Text 20, 30, EntityY (backdrop) ;Text 20, 40, EntityZ (backdrop) Flip Until KeyHit (1) End ; ----------------------------------------------------------------------------------- ; FUNCTION: Make3DBackdrop (cam, image$, maxTexSize, eOrder) ; ----------------------------------------------------------------------------------- ; cam = existing 3D camera ; image$ = image filename ; maxTexSize = max texture width & height (DEFAULT: 256, good for most gfx cards) ; eOrder = EntityOrder value (DEFAULT: 128, adjust if necessary) ; ----------------------------------------------------------------------------------- ; NOTE: Uses ClearTextureFilters, so TextureFilter is reset to default at the end... ; ----------------------------------------------------------------------------------- ; Returns backdrop pivot... ; ----------------------------------------------------------------------------------- Function Make3DBackdrop (cam, image$, maxTexSize = 256, eOrder# = 128) ; Image to use... bg = LoadImage (image$) ; Display and image dimensions... gW = GraphicsWidth () gH = GraphicsHeight () iW = ImageWidth (bg) iH = ImageHeight (bg) ; Handle to image's buffer... bgBuffer = ImageBuffer (bg) ; Remainder width of right/bottom image pixels after full maxTexSize textures grabbed... rightSize = iW Mod maxTexSize bottomSize = iH Mod maxTexSize ; How many times maxTexSize fits across the screen... scAcross = gW / maxTexSize scDown = gH / maxTexSize ; Used to calculate full 3D dimensions of backdrop... across = iW / maxTexSize down = iH / maxTexSize gWidth# = (scAcross * 2) + (2.0 / (Float (maxTexSize) / Float (rightSize))) gHeight# = (scDown * 2) + (2.0 / (Float (maxTexSize) / Float (bottomSize))) ; For best texture drawing... ClearTextureFilters ; Backdrop pivot... bd = CreatePivot (cam) ; Bah, trial and error produced this! Copies chunks of image onto separate sprites ; and positions each accordingly. Also sets EntityOrder so they're drawn behind ; everything else... For x = 0 To across For y = 0 To down sprite = CreateSprite (bd) EntityOrder sprite, eOrder texture = CreateTexture (maxTexSize, maxTexSize, 8 + 16 + 32) If x = across Then uSize = rightSize Else uSize = maxTexSize If y = down Then vSize = bottomSize Else vSize = maxTexSize CopyRect (x * maxTexSize), (y * maxTexSize), uSize, vSize, 0, 0, bgBuffer, TextureBuffer (texture) EntityTexture sprite, texture PositionEntity sprite, (x * 2) + (1 - (gWidth / 2.0)), (-y * 2) + (gHeight / 2.0) - 1, gWidth / 2.0 Next Next ; Free the loaded image... FreeImage bg ; Reset texture filter to default... TextureFilter "", 1 + 8 ; Return backdrop handle... Return bd End Function |
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