Questions about Sega Saturn

You can't render a 3D object without distorting it's geometry in screenspace.
The problem described in the video was not exclusive to quads distorted into triangles. Its for any quad that gets drawn in any shape other than a square ON SCREEN. So even if your render a perfect cube on saturn, as you rotate it, each quad is distorted in a different way on screen, causing the artifacts if they are rendered as transparent.
Oh ok I didnt realise that. Thanks for the clarification
 
So I guess the problem was due to the fact that it supported quads that were treated as distorted sprites? Or would it persist due to the fact that they were quads alone?
 
So I guess the problem was due to the fact that it supported quads that were treated as distorted sprites? Or would it persist due to the fact that they were quads alone?
The problem is a result of the way their quads were rasterized, which caused overdraw. Most rasterizers figure out the general area in which a primitive will be on screen, and then for each pixel in that area, they check if it should be filled, and with what color. Saturn does kind of the reverse. It picks the texels of a sprite, and plots them to screen. Its a sensible method for old-school 2D sprites, stretched senselessly to fit 3D requirements.
 
Transparency worked correctly when applied by VDP2 - the plane and background processor. But there were limits on where it could do this.

VDP2 over VDP2 worked, as did VDP2 over VDP1 (geometry could be marked to appear either beneath or on top of a transparent VDP2 layer)

Geometry (quads) over geometry didn't work unless done in separate VDP1 passes and then blended as layers in VDP2 (Burning Rangers did this iirc). But there was no doubt a large performance hit incurred.
 
When it comes to MGS it seems to be during the cut-scene and the whole screen seem to be affected. Looking at Crash Bandicoot it once again seem to be the intire screen and not a isolated part of the screen that can be seen in the Tomb Raider game. But I could be wrong...

/ Ken
 
When it comes to MGS it seems to be during the cut-scene and the whole screen seem to be affected. Looking at Crash Bandicoot it once again seem to be the intire screen and not a isolated part of the screen that can be seen in the Tomb Raider game. But I could be wrong...

/ Ken
 
When you see the character and the lake there is no transparancy in the water instead we have a mirror effect. The water scene with the fish seem to be similar to MGS and Crash, its the whole screen as there is not much of detail in the sky. Campare that to when Laura is looking up from the water on the ceiling. Also take a look at Lauras body how it distorts in the water when she is on the surface. Im sorry but the effect you see in Tomb Raider, transparancy, surface wave effect, distortion of the textures in the water when looking down or upp, distortion of the polygon character when she is in the water doesnt seem to be replicated. There where many Tomb Raider games released on the PS1 and noone had this effect implemented.

You have to continue your quest looking on Youtube to find a game that matches the first Tomb Raider game.

/ Ken
 
When you see the character and the lake there is no transparancy in the water instead we have a mirror effect. The water scene with the fish seem to be similar to MGS and Crash, its the whole screen as there is not much of detail in the sky. Campare that to when Laura is looking up from the water on the ceiling. Also take a look at Lauras body how it distorts in the water when she is on the surface. Im sorry but the effect you see in Tomb Raider, transparancy, surface wave effect, distortion of the textures in the water when looking down or upp, distortion of the polygon character when she is in the water doesnt seem to be replicated. There where many Tomb Raider games released on the PS1 and noone had this effect implemented.

You have to continue your quest looking on Youtube to find a game that matches the first Tomb Raider game.

/ Ken
Check the video more carefully there are sections that demonstrate something similar to the tomb raider video.
This is the only game though.
 
The frame buffer and textures sit on the same memory space in PS1's VRAM and you can treat them the same. The dev can specify any area of VRAM for the plolys to be rendered to, and any other area to be read as a texture. So you can even render to a portion of VRAM, and then use that rendered image as a texture for the next polygon. Thats how many screen warping effects were done on ps1, and I believe thats probably what they did in MGS. After rendering the whole 3D scene, use it as a texture for a mesh in screen space, and distort that mesh. You can either distort the verts themselves or just the UVs.
 
While on Saturn, effects like the Tomb Raider water were done by manipulating verts. Possibly helped to be using quads here, as simply displacing verts may have created a better effect than on tri meshes. But that's more of a hunch than anything.

Full screen effects on Saturn had to be done on VDP2, and I think options here were more limited than on PS, though they were possibly cheaper. For example, the Megaman water ripple on Saturn looks to be a simple line scrolling trick, while PS video output processor may not have been suitable for this.
 
Jumping Flash for the PlayStation has some nice frame buffer distortion effects for the underwater segments. (That is what is called, right?) All though, I do not know if it relates to the Tomb Raider footage from the Saturn version.
 
Jumping Flash for the PlayStation has some nice frame buffer distortion effects for the underwater segments. (That is what is called, right?) All though, I do not know if it relates to the Tomb Raider footage from the Saturn version.
Well one thing the Saturn could do was to keep some elements of the screen unafected from the ripple distortion effect and keep other elements affected. There is no game on the PS1 that did that except Bass Rise which in some scenes of the video I posted you can see portions of geometry showing the ripple distortion while others not.
Panzer Dragoon Saga and Zwei and Tomb Rider are nice high quality examples for their time, of 3D fames where you could see nice ripple effects only on the necessary areas.
 
Crash team racing's projectiles did localized distortion on their smoke trail. There are ways...
 
Now that I think about it, MegaMan Legends, both the original PS1 and N64 versions have a localized distortion effect too. It is only visible (as far as I know) with the ending boss fight. Its sequel has it as well. It is more pronounced there.
 
Here are some stuff that everybody needs to read if you are interested in the Sega Saturn hardware.

VDP1:
https://segaretro.org/VDP1_(Saturn)

VDP2:
https://segaretro.org/VDP2_(Saturn)

Sega Saturn VS Playstation 1
https://segaretro.org/Sega_Saturn/Hardware_comparison

Some games that show off the consoles graphic capabilities (VDP1 + VDP2)

Virtua Fighter 2 (Notice the high resolution layers and that there is not just one layer, the diversity of the ground textures, the animated faces and the animated backgrounds etc.).

Fighters Megamix (Notice the insane draw distance in this game, the number of background layers, the destructible cage and armour, the lightning, gouraud shading, pay attention to the sun in the desert level (33:45) etc.).

Thunder Force 5 (Again the insane draw distance of the water and the forest and the very nice effect of the ground on the industrial level, the texture quality etc.).

Radiant Silvergun (Very nice usage of the VDP1 and VDP2 with some incredible effects)

Soukyugurentai

/ Ken
 
Some more videos and some comparison videos...

Fighting Vipers (The number of background layers, the destructible cage and armour, the lightning, gouraud shading, the intensity of the color etc.)

Virtua Fighter 2 - (Arcade vs Sega Saturn)

VF2 vs Tekken 2 (Console versions)

Tekken 3 Arcade vs PS1 (Look at the backgrounds, the number of layers, notice the short draw distance on the ground on the console version etc.).

Thunder Force 5 - PS1

PS - I don't want this to escalate to some sort of fanboy war. So please keep the discussion civil :)

/ Ken
 
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