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Software Rendering with VDP2, Hexen use this to render all 3d

luisoft - Oct 7, 2010

		luisoft		Oct 7, 2010
			My first topic , my english is not good but i will try speak right. Im playing saturn hexen using SSF 0.9 and i love see how the game work inside and i discovered a interesting thing. Its the first game i see not use the VDP1 to handle 3d. In this game the VDP1 only scaling the sprites and all 3d is done by software using dma to vdp2 frame buffer. In SSF u can disable backgrounds and sprite in all games if i disable the sprite all 3d disaper but in this game the 3d not disaper . maybe the programmers use the old dos software rendering code to make a fast and easy port and its impressive see saturn rendering 3d with no vdp1. Its possible reset the slave cpu in SSF emulator like we do in Gens? I want to see if the 3d is rendering by slave cpu or only master cpu. [attachment=7724:sathexen.jpg]

		rorirub		Oct 12, 2010
			Burning Rangers does this too. I wonder if they render in software directly to the vdp2, or if they render with vdp1 and then copy the rendered frames to a vdp2 background (all the while still doing the normal vdp1 stuff). The first would be very demanding computationally, so they probably use the latter double-rendering trick. And copying the vdp1 rendered stuff over to a vdp2 background allows for transparencies to be applied on the rendered quads, this is how Burning Rangers does 3d transparencies iirc. It looks shit though, you can see that the transparent graphics are not in sync with everything else, and that they are rendered at half the resolution of everything else. You can't reset cpus individually in SSF, but you can can enable a cpu register view mode in one of the ini files, and you can set the slave sh2 speed at the options. You can tell from that screenshot that the slave sh2 is active though, though it may even just handle something extremely trivial like in most games.

		mrkotfw		Oct 13, 2010
			luisoft said: My first topic , my english is not good but i will try speak right. Im playing saturn hexen using SSF 0.9 and i love see how the game work inside and i discovered a interesting thing. Its the first game i see not use the VDP1 to handle 3d. In this game the VDP1 only scaling the sprites and all 3d is done by software using dma to vdp2 frame buffer. In SSF u can disable backgrounds and sprite in all games if i disable the sprite all 3d disaper but in this game the 3d not disaper . maybe the programmers use the old dos software rendering code to make a fast and easy port and its impressive see saturn rendering 3d with no vdp1. Its possible reset the slave cpu in SSF emulator like we do in Gens? I want to see if the 3d is rendering by slave cpu or only master cpu. [attachment=7724:sathexen.jpg] Very interesting... this gives me an... idea!

		luisoft		Oct 14, 2010
			Maybe this is the way AM2 found to create the Saturn Shenmue prototype, use the VF2 engine with VDP1 and master cpu to handle people and slave cpu + vdp 2 + software rendering to handle the 3d of houses in this way its possible use more ram to textures.

		mrkotfw		Oct 19, 2010
			luisoft said: Maybe this is the way AM2 found to create the Saturn Shenmue prototype, use the VF2 engine with VDP1 and master cpu to handle people and slave cpu + vdp 2 + software rendering to handle the 3d of houses in this way its possible use more ram to textures. I doubt it...