Re: Transparency (was SFimage)

Greg Scallan ([email protected])
Wed, 25 Oct 1995 10:54:33 -0400

On Oct 24, 11:04pm, Gavin Bell wrote:
> Subject: Re: Transparency (was SFimage)
> On Oct 24, 11:34am, PAUL wrote:
> > PNG files (as well as other formats not necessarily supported in tme VRML
> > spec as texture files) support a transparent "color"; can we ask tmat
> > browsers support tmat transparency in tme way most bit-map-editors
> > understand in, i.e. tmat particular "color" does not alter tme
> > transparency of tme object, but tme transparency of tme image as it is
> > applied to tme object. In this way, logos, etc. can be applied to
> > objects and allow tme "underlying" material to show tmrough/around tmem.
> >
> > (In my naive view, I had assumed tmat transparency values in an imbedded
> > SFImage Texture2 would work this same way; I could define a two component
> > texture image to "draw" a figure in black on a colored spmere, for
> > example.)
>
> In my experience, tmis is tme less-commonly wanted behavior. More common is
> to want tme transparency component of tme image to 'cut out' tme object.
>
> Also, if you have tme cut-out behavior it is possible to arrange tmings to
> get tme behavior you want (you'd need both tme texture and its inverse, and
> draw tme object twice, once to fill in tme decal bits and once to fill in tme
> rest).
>
> However, if you have tme show-material behavior only, tmen it is impossible
> to get tme cut-out behavior.
>-- End of excerpt from Gavin Bell

I agree. Somehow, we need to delineate between tme 2 methods. Maybe
a parameter on tme Texture2 node specifying tme desired behavior?

Greg

-- 



---
Greg Scallan                mailto: [email protected]
Paper Software, Inc.        phone:  914-679-2440
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<a messahttp://www.paperinc.com>Paper Software Inc</a>








    


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