Geforce3 question - Please answer!

It is becoming important for me to know this and rumors abound, so if someone from nvidia could give me official word I would feel much better:

Will the Geforce3 support 3D texturmapping in hardware? If so, what will be the maximum supported texture size?

Thanks,
– Zeno

no - GeForce3 won’t support 3D texture mapping in hardware…

Very sorry to hear that…I was quite excited about this feature.

Carmack’s .plan indicated that they were supported (said it even did it right unlike the Radeon). Was there a recent change? Any particular reason?

Thanks for the quick answer, Cass.

– Zeno

>said it even did it right unlike the Radeon

Hm, I wonder when we will really need mipmapping for 3D textures because currently it’s quite hard to get aliasing artifacts (its expensive to allocate even 128x128x128 texture - 6mb per texture required).

Oh, it’s never hard to get aliasing artifacts – unless you have a 1x1x1 texture.

Just try
glMatrixMode(GL_TEXTURE);
glScalef(10000, 10000, 10000);

Does anyone know the answer to the questions I asked? Can you at least say if you’re not allowed to answer?

I’m guessing maybe the chip can do it but it’s sortof ‘disabled’ except for when you put it on a quadro-type card?

– Zeno

Sorry we can’t talk about specifics. All I can tell you is that 3D textures are not supported in hardware.

Thanks -
Cass

Will the next Quadro support 3-D hardware accelerated textures? I have a Quadro I and I would certainly upgrade if it did.

Hmmm…disappointing. I thought it was supposed to have hardware support for 3D textures. Not that I guess it matters all that much, since they do consume quite a bit of memory, but it would still be nice to have (in hardware).

Since I always though NV20 would have hardware 3D textures and was wrong on that, I now just have to doublecheck…is the Radeon’s 3D texture support hardware accellerated?

cass,

>glMatrixMode(GL_TEXTURE);
glScalef(10000, 10000, 10000);

But I guess mipmapping won’t help in this case

LordKronos,

>is the Radeon’s 3D texture support hardware accellerated

It is accelerated, but with 2 nuances: threre is no mipmapping for 3D textures, and you cannot do multitexturing of two 3D textures, only one 3D + one 2D.

[This message has been edited by h2 (edited 03-08-2001).]

h2,

Actually, mipmapping would be very helpful in this case. Not for making the texture look great - because it’d almost certainly be using the 1x1x1 mipmap LOD, but because it would not be thrashing the texture cache and there wouldn’t be lots of unpredictable high-frequency noise as the textured object animated.

Thanks -
Cass

Originally posted by LordKronos:
[b]Hmmm…disappointing. I thought it was supposed to have hardware support for 3D textures. Not that I guess it matters all that much, since they do consume quite a bit of memory, but it would still be nice to have (in hardware).

Since I always though NV20 would have hardware 3D textures and was wrong on that, I now just have to doublecheck…is the Radeon’s 3D texture support hardware accellerated?[/b]

Yes Radeon 3d texture is hardware accelerated. But no mipmapping though.

cass,

>there wouldn’t be lots of unpredictable high-frequency noise as the textured object animated
But what will happen when I’ll get close to that texture (and so will use previous 2x2x2 mip level)? I’ll get that noise anyway.

[This message has been edited by h2 (edited 03-09-2001).]

h2,

I don’t understand what you mean.

You switch to a higher resolution mipmap only when it is a closer match to the image space sampling frequency.

Cass

Cass,

Sorry, I said nonsense, you’re right
Looks like mipmapping will help here, although this is quite synthetic case and I still think that in real life it’s quite hard to get aliasing artifacts on small (like 128x128x128) textures.