nesa

I'm trying to make an 8 input mixer shader, but for some reason I can't get all 8 textures into the shader, and to make things worse: only on some computers!

I've attached sample patch and shader, which should display 6 layers with their numbers(1,2,3,4,5,6) but on my computer, I see only layers 2,3,4 and 6...

in both Leopard 10.5.2 and windows xp sp2, same results.

Same bug appears on dual g5 with NVIDIA GeForce 6800 Ultra with 256MB, mac os 10.4.11

But it works on dual xeon mac pro with ATI Radeon X1900 XT 512Mb, mac os 10.4.11

So I'm wondering if anyone else can reproduce, and are there any workarounds?

I've tested this patch on mb pro:
GeForce 8600M GT:

  Chipset Model:	GeForce 8600M GT
  Type:	Display
  Bus:	PCIe
  PCIe Lane Width:	x16
  VRAM (Total):	512 MB
  Vendor:	NVIDIA (0x10de)
  Device ID:	0x0407
  Revision ID:	0x00a1
  ROM Revision:	3212

multiple-texture-input-to-shaderslab-bug

mbp, 10.5.2, ati x1600, 256MB vram, but i guess you already knew that.

i guess the obvious answer is the card is limited in the number of texture states it can create per shader. i wonder if non-rectangular textures would help.

hopefully wes or anton or andrew know more...

works over here.
mbp, 10.5.2, ati x1600, 256MB vram, but i guess you already knew that.

hopefully wes or anton or andrew know more...


Yeah, I tried this before, or something similar, and different 

hardware support a different number of texture samplers, min of two, 

max of, well, whatever the latest greatest is.

If you want to query this value for your card(s), youd have to look 

http://developer.apple.com/graphicsimaging/opengl/capabilities/index.html

I *think* I am reading that correctly, and inferring the proper 

relationships. All I know is that uber shaders are not the way to go, 

as much as I did not like to hear it. You are probably better of using 

a few mixing shaders and chain them to be honest.

> I'm trying to make an 8 input mixer shader, but for some reason I 

> can't get all 8 textures into the shader, and to make things worse: 

> I've attached sample patch and shader, which should display 6 layers 

> with their numbers(1,2,3,4,5,6) but on my computer, I see only 

> in both Leopard 10.5.2 and windows xp sp2, same results.

> Same bug appears on dual g5 with NVIDIA GeForce 6800 Ultra with 

> But it works on dual xeon mac pro with ATI Radeon X1900 XT 512Mb, 

> So I'm wondering if anyone else can reproduce, and are there any 

Yeah, I tried this before, or something similar, and different  
hardware support a different number of texture samplers, min of two,  
max of, well, whatever the latest greatest is.

If you want to query this value for your card(s), youd have to look  
for MAX_TEXTURE_UNITS

I *think* I am reading that correctly, and inferring the proper  
relationships. All I know is that uber shaders are not the way to go,  
as much as I did not like to hear it. You are probably better of using  
a few mixing shaders and chain them to be honest.

> Hi all,
>
> I'm trying to make an 8 input mixer shader, but for some reason I  
> can't get all 8 textures into the shader, and to make things worse:  
> only on some computers!
>
> I've attached sample patch and shader, which should display 6 layers  
> with their numbers(1,2,3,4,5,6) but on my computer, I see only  
> layers 2,3,4 and 6...
>
> I've tested this patch on mb pro:
> GeForce 8600M GT:
>
>  Chipset Model:	GeForce 8600M GT
>  Type:	Display
>  Bus:	PCIe
>  PCIe Lane Width:	x16
>  VRAM (Total):	512 MB
>  Vendor:	NVIDIA (0x10de)
>  Device ID:	0x0407
>  Revision ID:	0x00a1
>  ROM Revision:	3212
>
> in both Leopard 10.5.2 and windows xp sp2, same results.
>
> Same bug appears on dual g5 with NVIDIA GeForce 6800 Ultra with  
> 256MB, mac os 10.4.11
>
> But it works on dual xeon mac pro with ATI Radeon X1900 XT 512Mb,  
> mac os 10.4.11
>
> So I'm wondering if anyone else can reproduce, and are there any  
> workarounds?
>
> Thanks,
> nesa
>
>
>


On Apr 9, 2008, at 11:16 AM, Robert Ramirez wrote:

> mbp, 10.5.2, ati x1600, 256MB vram, but i guess you already knew that.

> i guess the obvious answer is the card is limited in the number of 

> texture states it can create per shader. i wonder if non- 

It's an NVidia vs. ATI issue. For the fixed function pipeline and the 

GL_MAX_TEXTURE_UNITS variable (which is what we check to limit these 

sorts of things), NVidia cards are limited to 4 textures for multi- 

texturing. In a future release we may be able to use 

GL_MAX_TEXTURE_IMAGE_UNITS_ARB for the programmable pipeline, but the 

solution in the meantime is to separate the shader into multiple 

http://groups.google.com/group/comp.graphics.api.opengl/browse_thread/

On Apr 9, 2008, at 11:16 AM, Robert Ramirez wrote:
>
> works over here.
> mbp, 10.5.2, ati x1600, 256MB vram, but i guess you already knew that.
>
> i guess the obvious answer is the card is limited in the number of  
> texture states it can create per shader. i wonder if non- 
> rectangular textures would help.

It's an NVidia vs. ATI issue. For the fixed function pipeline and the  
GL_MAX_TEXTURE_UNITS variable (which is what we check to limit these  
sorts of things), NVidia cards are limited to 4 textures for multi- 
texturing. In a future release we may be able to use  
GL_MAX_TEXTURE_IMAGE_UNITS_ARB for the programmable pipeline, but the  
solution in the meantime is to separate the shader into multiple  
passes each with 4 inputs.

http://groups.google.com/group/comp.graphics.api.opengl/browse_thread/ 
thread/876176f12815c454

Thanks for clarifying this guys, stacking is inevitable anyways for 

Thanks for clarifying this guys, stacking is inevitable anyways for  
what I had in mind!

I'm glad I found this article. I have been banging my head against this for several days. Thanks for the info guys.

multiple texture input to shader/slab bug?