BlenderBim CSS Hatchpatterns - multiply or transparent fill on Cut elements/objects?

A by Ace on 19 Mar 2024, edited 26 Mar 2024 # +2 votes

When printing to SVG and cutting an object no matter the opacity or the fill settings it does not seem able to be transparent or act as a multiply effect, the effect is you cant see any 2d elements below a cut element at all

in this case demolished elements block the 2d information and floor information of new elements when overlapping in plan:

This is the desired result:

to see the 2d info of the door through the wall pattern

This is the material pattern code:

<_pattern id="brickdemolish" width="3" height="3" patternTransform="rotate(45 0 0)" patternUnits="userSpaceOnUse">

<_path style="fill: none;" d="M 0 0 3 0 3 3 0 3" />

<_line x1="1" y1="0" x2="1" y2="3" style="stroke:lightblue; stroke-width:0.25" />

<_line x1="2" y1="0" x2="2" y2="3" style="stroke:lightblue; stroke-width:0.25" />

</_pattern>

(I've added the underscores because not sure how to display the code without it)

I've tried these approaches and none have given the desired results

![]<path style="fill: none;" d="M 0 0 3 0 3 3 0 3" />

![]<path style="fill: transparent;" d="M 0 0 3 0 3 3 0 3" />

![]<path style="fill: white; opacity: 0.50;" d="M 0 0 3 0 3 3 0 3" />

![]<path style="fill: white;" d="M 0 0 3 0 3 3 0 3" opacity="50%"/>

![]<path d="M 0 0 3 0 3 3 0 3" fill="white" style="mix-blend-mode: multiply;" />

and variations of these without success

setting the opacity in the CSS file itself also doesnt affect the fill and even at 0% still bloacks out the background

I am not a coder / programmer so my knowledge of this is through trial and error I'd be very pleased to know I missed something simple and basic, any feedback is appreciated.

M by Massimo on 19 Mar 2024 # +1 votes

I'm interested too because i tried many times but i don't really understand how opacity/transparency work in svg ...

T by theoryshaw on 19 Mar 2024, edited 19 Mar 2024 # +1 votes

Would love to control transparency too.

Maybe we could add some type of EPset_Drawing.Transparency parameter. That is, for those objects assigned to the parameter, they will not 'hide' what is beyond during svg creation. It would still create a svg 'path' at the cut that you could style with varying css opacity fills--to adjust the amount of transparency. Just brainstorming.

J by JanF on 19 Mar 2024 # +1 votes

In my tests ifcopenshell does some sort of visibility check and crops the invisible elements - that means no matter your svg magic, you will not see the lines underneath, they're just not there.

@Andrej730 do you maybe know how to fix this?

S by steverugi on 20 Mar 2024 #

a quick 'n dirty patch for me is to use the outliner in InkScape (or Illustrator or..), especially if doors or other elements are SVG-grouped it's not that tedious to change their order and visualization, right?

A by Ace on 20 Mar 2024 # +1 votes

@steverugi said:

a quick 'n dirty patch for me is to use the outliner in InkScape (or Illustrator or..), especially if doors or other elements are SVG-grouped it's not that tedious to change their order and visualization, right?

At the end of the day that's what I do aswell, thanks Steve hahaha,

an Inhouse (/ In BlenderBim) workaround is to (in this case) hide the demolished elements and use Fill areas to represent them,

because the transparency/ opacity is for some reason taken into account here and it gives you the desired result,

when exporting as a pdf in Inkscape it resets the opacity still for some reason though

A by Ace on 20 Mar 2024 # +1 votes

@theoryshaw said:

Would love to control transparency too.

Maybe we could add some type of EPset_Drawing.Transparency parameter. That is, for those objects assigned to the parameter, they will not 'hide' what is beyond during svg creation. It would still create a svg 'path' at the cut that you could style with varying css opacity fills--to adjust the amount of transparency. Just brainstorming.

I would back this 100%, preferably as much is done in BlenderBim with the real geometry as possible

B by Bimlooser on 26 Mar 2024 #

@Ace can you please drop the .css file and a partial .svg with the problem inside? Not so skilled but I'd like to try an attempt.

Thanks