Re: view/renderer handling of surface shaders

[Roger H. <rog...@mi...>]

On 1 Feb, 2007, at 17:27, James W. Walker wrote:

>
> On Feb 1, 2007, at 4:30 AM, Roger Holmes wrote:
>
>> I would think that attributeSurfaceShader is for any surface
>> shaders within shapes and shaderSurface is for any loose surface
>> shaders.
>
> If a surface shader belongs to an attribute set, but that attribute
> set is not attached to a shape, do you consider that "loose"?

No.

>
>> The  'inheritance' rules for these are different. A loose surface
>> shader overrides any  previous loose surface shaders up up to the
>> end of the group it is in. A  surface shaders in an attribute set
>> attached to a shape overrides any loose surface  shaders and any
>> previous attribute surface shaders up until the end of the shape it
>> is attached to. Well, I think that's how it works anyway.
>
> It still seems to me that the view could have a single concept of
> current surface shader (as the IR does), which is the most recently
> seen surface shader, subject to pushing and popping when you enter/
> leave a group and when you start/finish a geometry.

But pushing and popping the graphics state is a slow operation, you  
would
not want to do it for every geometry, and certainly not for every  
part of
a geometry (you can have an attribute set on every vertex, edge and
triangle for some geometries, though what a surface shader does for
a point I wouldn't care to guess, but I think I have seen them on edges
when we were first developing 3DWorld).

>
>> I am not sure of the exact rules when a surface shader is in an
>> attribute set attached to (rather than being a member of) a group
>> and there is a loose surface shader in the group or there is a
>> loose attribute set with a surface shader as a member of the group.
>
> I'm not sure that I've ever tried putting an attribute set on a
> group.  My guess would be that it would be treated as if it were a
> member of the group, but before the first normal member.

Seems reasonable.

>
>> I guess attributeSurfaceShader gets changed by ones in any
>> attribute set and shaderSurface gets changed by any loose ones, and
>> that if attributeSurfaceShader is not nil, it uses that, otherwise
>> it uses shaderSurface unless that  is nil, in which case there is
>> no texture and it looks for colours instead.
>>
>> On 1 Feb, 2007, at 07:00, James W. Walker wrote:
>>
>>> I'm trying to figure out why the Interactive Renderer does the wrong
>>> thing with the test file "texture-interference.3dmf" that I recently
>>> committed.  I think it has to do with the fact that TQ3ViewStackItem
>>> has two surface shader members, shaderSurface and
>>> attributeSurfaceShader.  Anyone know why?  It seems crazy.  But  
>>> maybe
>>> I'm just tired.
>>>
>>> -------------------------------------------------------------------- 
>>> -
>>> -
>>> ---
>>> Using Tomcat but need to do more? Need to support web services,
>>> security?
>>> Get stuff done quickly with pre-integrated technology to make your
>>> job easier.
>>> Download IBM WebSphere Application Server v.1.0.1 based on Apache
>>> Geronimo
>>> http://sel.as-us.falkag.net/sel?
>>> cmd=lnk&kid=120709&bid=263057&dat=121642
>>> _______________________________________________
>>> Quesa-develop mailing list
>>> Que...@li...
>>> https://lists.sourceforge.net/lists/listinfo/quesa-develop
>>
>>
>> --------------------------------------------------------------------- 
>> -
>> ---
>> Using Tomcat but need to do more? Need to support web services,
>> security?
>> Get stuff done quickly with pre-integrated technology to make your
>> job easier.
>> Download IBM WebSphere Application Server v.1.0.1 based on Apache
>> Geronimo
>> http://sel.as-us.falkag.net/sel?
>> cmd=lnk&kid=120709&bid=263057&dat=121642
>> _______________________________________________
>> Quesa-develop mailing list
>> Que...@li...
>> https://lists.sourceforge.net/lists/listinfo/quesa-develop
>
>
> ---------------------------------------------------------------------- 
> ---
> Using Tomcat but need to do more? Need to support web services,  
> security?
> Get stuff done quickly with pre-integrated technology to make your  
> job easier.
> Download IBM WebSphere Application Server v.1.0.1 based on Apache  
> Geronimo
> http://sel.as-us.falkag.net/sel? 
> cmd=lnk&kid=120709&bid=263057&dat=121642
> _______________________________________________
> Quesa-develop mailing list
> Que...@li...
> https://lists.sourceforge.net/lists/listinfo/quesa-develop