Material preset "Metal" for extruded custom shapes

[Miklos Vajna]

Hi Regina,

On Sun, Jan 30, 2022 at 11:20:33PM +0100, Regina Henschel <rb.henschel at t-online.de> wrote:
> I want to make rendering similar to actual rendering in MSO in case we have
> an import from MSO. MSO uses for the attribute c3DDiffuseAmt the special
> value 43712/65536 in case of "Metal", otherwise 65536/65536.
> Currently I use this special value in my ongoing work [4] to detect, that
> the shape 'wants' a Metal-rendering like MSO. The attribute c3DDiffuseAmt
> has the corresponding attribute draw:extrusion-diffusion in ODF. So a
> document imported from MSO binary format and then saved to ODF looks still
> as MSO-kind, when reopening the document. But it is somehow a misuse of that
> ODF attribute.
> Do you think, that I should stay with that approach? Alternative would be to
> use a marker in an interoperability bag. But that would loose the
> information when writing to ODF.
> 
> Opinions?

It seems to me that both of these are useful -- could we have both? I.e.
add a new "diffuse metal" (or any other suitable name) property for the
MSO behavior and keep our "metal" for the existing LO way?

Then you could map the MSO c3DDiffuseAmt to the "diffuse metal", and
have both types of metal in the same document. Yes, this means going
through the usual new feature checklist[1], but if you have time to do
that, probably that would be better than a misuse or a grab-bag.

Regards,

Miklos

[1]
https://wiki.documentfoundation.org/Development/Writer#Adding_a_new_feature
has that list, but it's not specific to Writer, perhaps we should move
that to some more common place.