Re: Workaround for this bug?

[Keith W. <kw...@cs...>]

On Fri, 21 Jan 2005, Frank Condello wrote:

> First ensure the alpha in your art is not pre-multiplied (likely the case 
> already) then put the sun shape in a display group under a fog object with 
> its visibility set to false. This will ensure no fog is drawn on the sun, 
> which is typically a desired effect on all celestial bodies. Also place a 
> Lambert shader before the sun geometry to turn off any potential specular 
> highlights, since they may display a similar artifact as fog.

I have a question on this approach.  Is there something inherant about the 
display group that is supposed to make this alpha-with-fog thing work 
properly, or is that just the way you suggested to make sure the fog is 
submitted prior to the sun object?

I ask because before trying to group the fog with the sun, I quickly tried 
submiting a fog turned off just prior to submitting the sun and then 
submitting the fog turned on again just after the sun...but the alpha-fog 
error is still present.  Is that what you would have expected?  Is the 
display group required?

My problem with the display group is that I can't create it because I 
don't have a TQ3Object to add to it.  My sun (and all the objects in my 
program) are TQ3TriMeshData, not TQ3Object.  It won't compile passing that 
to Q3Group_AddObject.  Same is true for passing a TQ3FogStyleData to the 
group.  When I do this, Q3Group_AddObject returns NULL, which is supposed 
to mean there was an error with creating the group.

Don't get too hung up my grouping problem is I am correct in my first 
paragraph.  If the alpha-fog problem should be fixed by submitting a 
turned off fog prior to submitting the alpha object, then why isn't that 
working?

Thanks for any help.

________________________________________________________________________
Keith Wiley         kw...@cs...         http://www.unm.edu/~keithw

"Yet mark his perfect self-contentment, and hence learn his lesson,
that to be self-contented is to be vile and ignorant, and that to
aspire is better than to be blindly and impotently happy."
                                            --  Edwin A. Abbott, Flatland
________________________________________________________________________