Frontside and backside colour

[ChrisKa]

Hello,

if I import a COLLADA-File I can change the (frontside) colour with the following Code:
Sketchup.active_model.active_entities.each{|e|e.material="green"};

I want to do the same with the backside of the areas, but this Code doesn't work:
Sketchup.active_model.active_entities.each{|e|e.back_material="green"};

Can somebody help me why this Code doesn't work?

Thanks,
Chris

[thomthom]

You're getting errors, right?

Only faces have the .back_material method - so when you iterate a whole entity collection you're also iterating over edges, guides etc. You need to ensure you're applying back material to only faces.

If that is not the case - then you need to provide more info on what you are doing and exactly what "isn't working". (Errors or unexpected results. Sample models help.)

[ChrisKa]

Hy thomthom,

this is my COLLADA-File: COLLADAfile.zip

The frontside colour I can change. This you can see on the file "change_frontside_colour.jpg".

And now my problem is that I can't change the backside colour!
"change_backside_colour_ERROR.jpg"

Thanks a lot for your help,
ChrisKa

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COLLADAfile.zip

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[thomthom]

That is it - you are trying to call .back_material on a ComponentInstance.

You need to ensure you got a Face.

Sketchup.active_model.active_entities.each{|e|e.back_material="green" if e.is_a?(SketchUp::Face)};

But note that if the geometry of yours is inside a group or component your code won't dig into the nested groups/components. As you have the code now, the currently active context (open component) must be the one containing the faces.

[ChrisKa]

Sorry, but I don't understand.
Do you mean that I have to explode the component for working this code.

Is there a possibility that I can change the backside-colour inside the component like the frontside-colour?

[thomthom]

For that simple example you provided you only need to open the component before you run the script.

But I don't know the bigger context where you use this.

Here is a snippet that process the entire model:

<span class="syntaxdefault"><br /></span><span class="syntaxcomment"># Process entities in the root model context<br /></span><span class="syntaxdefault">for e in Sketchup</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_model</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">entities<br />  next unless e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(</span><span class="syntaxdefault">SketchUp</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">  e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">material</span><span class="syntaxkeyword">=</span><span class="syntaxstring">"green"<br /></span><span class="syntaxdefault">  e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">back_material</span><span class="syntaxkeyword">=</span><span class="syntaxstring">"green"<br /></span><span class="syntaxdefault">end<br /></span><span class="syntaxcomment"># Process all groups and components<br /></span><span class="syntaxdefault">for d in Sketchup</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">active_model</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">definitions<br />  next if d</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">image</span><span class="syntaxkeyword">?<br /></span><span class="syntaxdefault">  for e in d</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">entities<br />    next unless e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">is_a</span><span class="syntaxkeyword">?(</span><span class="syntaxdefault">SketchUp</span><span class="syntaxkeyword">;;</span><span class="syntaxdefault">Face</span><span class="syntaxkeyword">)<br /></span><span class="syntaxdefault">    e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">material</span><span class="syntaxkeyword">=</span><span class="syntaxstring">"green"<br /></span><span class="syntaxdefault">    e</span><span class="syntaxkeyword">.</span><span class="syntaxdefault">back_material</span><span class="syntaxkeyword">=</span><span class="syntaxstring">"green"<br /></span><span class="syntaxdefault">  end<br />end<br /></span>

[ChrisKa]

I would like to import the COLLADA-File with the "Ruby-Console".
The code should be in one line.

The result should look like this file result-OK.jpg

I still have the problem with the backside! See result-false.jpg

Do you have an idea?
Thanks,
Chris

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[TIG]

Your code currently makes everything in the model.active_entities have the specified material.
Because the imported geometry arrives inside a component your code gives that material to the instance - NOT its contents.
Faces inside a component [or group] that have no material applied to them [front or back] will initially show in the default material.
Then if you give the 'container' a material then those faces will be displayed as if they had that material, BUT they are actually still in the default material.
If you want to give a material to the faces inside a component you need to use something like this.
Assuming that you want every face in the model to use that material...
Sketchup.active_model.definitions.each{|d|next if d.image?; d.entities.each{|e|next unless e.class==Sketchup::Face; e.material="green"; e.back_material="green"}}
To ALSO process any faces in the model's entities use this:
Sketchup.active_model.entities.each{|e|next unless e.class==Sketchup::Face; e.material="green"; e.back_material="green"}
You can obviously mess around with materials and so on...
You could even limit the change to the imported component [its component name ISN'T the same as the dae file so we must get all components before we start and then find which one was [or ones were] added by the import]...
ds=Sketchup.active_model.definitions.to_a; ###add your importer code here...; ds=Sketchup.active_model.definitions.to_a-ds;###ds is an array of just the imported component[s]; ds.each{|d|d.entities.each{|e|next unless e.class==Sketchup::Face; e.material="green"; e.back_material="green"}}

[ChrisKa]

Thanks a lot for your help.
Now this code is very helpful for me!

ChrisKa