Material preset "Metal" for extruded custom shapes

[Armin Le Grand]

Hi Regina,

I remember that we did 'metal' *before* other competitor(s), so that 
same name is/must be just coincidence. Like 'Gold' it was to give the 
user more possibilities/selections to play around. Some lighting 
presets, if you wish.

HTH!

ALG

On 1/30/22 23:20, Regina Henschel wrote:
> Hi all, hi Miklos,
>
> the UI of Microsoft Office provides a material preset "Metal". Our UI 
> provides that too. Both ODF and MSO standards have a Boolean attribute 
> whether "Metal" has to be used or not. But the way "Metal" is actually 
> rendered in MSO [3] is different from how ODF specifies it [1] and how 
> MSO specifies it [2].
>
> 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?
>
> [1] ODF specifies, "true: the specular color for the shading of an 
> extruded shape is gray (red green and blue values of 200) instead of 
> white and 15% is added to the specularity."
> [2] MSO specifies, "A bit that specifies whether the 3-D shape 
> lighting algorithm will treat the specular color as the diffuse color."
> [3] Actual the rendering in MSO looks as if the first light is 
> evaluated for specularity same as in material preset "Plastic" but the 
> specular color is not gray but it is the same as the object color.
> [4] https://gerrit.libreoffice.org/c/core/+/128449
>
> Kind regards,
> Regina

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ALG (PGP: EE1C 4B3F E751 D8BC C485 DEC1 3C59 F953 D81C F4A2)