Question about the EntityInfo window and material icons

I am trying to determine the meaning and purpose of the one or two icons that are in the upper left hand corner on the Entity info window. I can deduce that they indicate the status of styles or materials in the selected entity. There is nothing I can find in the online help or by searching the forums that describes these. Perhaps they are intuitively obvious but my intuition is failing me.

-louie

Do you mean the one that is often a square that is split into a white and a gray triangle?

Edit: I see you are on a Mac, so the layout is no doubt different.
Could you post a screenshot.


Are you referriing to the “dive flags” shown in green and white, above? If so, those show the materials applied to front and back faces of the selected face. In this example it’s just the default material. If you select a group, component, or edge, you only get one dive flag because those entities can only have one material.

… and the colour shown on the edge flag only makes any difference if your style is set to “Colour by material”: if it’s “default” the edge takes the colour of the group/component it is within. (The colour can be set away from the default just like faces within a group/component… but can only be set to a colour that is in the “in model” library)

Thanks for the explanation this is what I was referring to. This helps but it is still confusing although after a little messing around I think I have a better understanding now.

The flag on the right is the color/material for the front face, in this case the default for the style. The flag on the left is the color/material for the back face, also the default as shown. So what this means that the front face is using the default color/material which is white. And the back is also using the default color/material which is grey.

One confusion is that flag in the Entity info is different from the Color/material picker at least on the Mac. On the color/material picker the diagonal is the other way top right to bottom left. Also there is no documentation that I have found that explains what these flags mean. I only finally figured it out by messing around with editing a style and accidentally changing my default Woodworking style back color to hot pink.

Another confusion stems from the fact that I have been learning SketchUp through woodworking tutorials where everything is pretty much simple 3D modeling. What I’ve discovered is that as soon as you push pull a 2D shape every all the exterior faces are considered “front” and all the interior faces are not back. Practically speaking the back is never seen and irrelevant.

Finally I learned that a material applied at a lower level in the hierarchy, on an individual face for example overrides a material/color applied to the component. This fact was driving me crazy as at first I was not careful to pay attention to context where I applied the material. For a while I thought the paint bucket was flaky because I could not replace some materials. Turns out that they were applied at a lower level.

A very useful tool has been the CutMap plugin that installed an item in the item context menu to remove “all materials” which resets the model back to using only the default material. I did not find any function within SketchUP that provides the same functionality.

I hope that this may help others and please let me know if any of this is not correct.

-louie

Another potential point of confusion is that SketchUp’s default material is special. It is the only one that can paint both the front and back sides of a face at the same time. That’s why its icon has the diagonal “dive flag” appearance. All other materials paint only the side on which they were applied. To make matters more confusing, a face can have a non-default material painted on one side and the default material on the other side. Which color shows on the default side depends on whether it is “front” or “back”.

Another oddity is when I start drawing a piece as a 2D shape, lets say a rectangle the back face is facing front. I double checked and made sure that I clicked the front view on the tool bar. Actually no mater which direction I am viewing when I draw a 2D shape the face I see gets the back color.

Is this expected behavior or do I have some preference set strangely?

Ultimately this doesn’t matter to me since I am working one shop drawings with 3D components where all the external faces are “front” and all the internal faces are “back”.

-louie

If you are drawing on the red-green plane (z=0), SketchUp will automatically orient a loose face so that the back side faces up. As you suggest, it does this based on the assumption that you will likely pushpull the face up to a solid, and will want the front sides pointed outward.

For other locations it will usually orient the front side toward the camera. If the face shares an edge with a pre-existing other face, it will orient the new face the same way as the other one.

This is explained in detail in this User Guide sub-section:
Adding Colors and Textures with Materials

This User Guide page: Drawing Basic Shapes
… shows all shapes drawn on the XY “Ground Plane” facing down (in preparation for pulling up.)

As well as this page: Creating your first 3D model in SketchUp

It is by design but I do not see it explained much at all in the User Guide.

For other new “stand alone” faces in the Red/Blue plane and Green/Blue plane seeing front v.s. back seems to entirely depend on which diagonal you draw for the rectangle. And for other shapes it depends on drawing the perimeter clockwise or counter clockwise.

On my PC, v 2016, it it opposite. Front is on the left, back is on the right (in the Entity Info window.)

Thanks everyone for the additional information.

-louie

I’m not sure this is correct: I think that any texture/material with a transparency value can also be pained on both the front and the back at the same time.

(Although sometimes I want it to do this and it doesn’t {eg glass} and sometimes I want it not to and I have to edit the individual faces to get the results {eg walls where I want to see through them from the outside (back) and have them solid from the inside (front)… not figured out a consistent painting method that works 100% of the time yet.).

@gadget2020, you are right about other textures, imported say from internet.
Have you considered the turning point in opacity (for both jpg and png texture) seems to be 99%
=<99% results in painting both sides at once
=100% paints the visible side of a face

I couldn’t get SU to do so otherwise and can’t remember it to work different. Not saying you may have had a different experience.

I think if a face already has a transparent fill and you want to fill it with another then it works like a solid fill (only filling the surface clicked on)… but I’ve not tested that.

(PS I meant the transparency slider at the bottom of the “edit materials” window)

Of course I was starting from a default textured face on both sides.
A one or two sided painted face obstructs painting the non-visible side.

This quote, " First, you can set the colors of your default faces. Since every face has a front and a back, they give you two selections to make. I really wouldn’t change these, since it is a good idea to standardize the default face colors so you can readily identify if a face has a material applied to it or not, regardless of which style you have active. "

is from Matt Donley’s first book, SketchUp to Layout. It’s from page 64 “Face Settings”. For the record, the book is well enough thought out that it brings simplicity and clarity to what was getting overwhelming. The author was a carpenter, so his approach is realistic and practical but he also has ‘hands on’ IT experience that enables us to understand his presentations. (IT - Information Technology)

Ok here’s something to try. It not something I would do when building a model but it seems to show some of the internal behavior.

  1. Make a 2D rectangle on the base (xy) plane. As described above this shows the back face up and front face down.

  2. Apply a different color to the front and back faces. These show up as expected in the Entity info, front color in the left flag and back color in the right flag.

  3. Pull the face up using Push/Pull and resulting 3D object will now have the color you assigned to the back on the outside and the flags in the Entity info will be swapped.

  4. Now using Push/Pull push the top of the 3D object down through it bottom and as you pass through the object changes to the color what was assigned to the back face. Strangely the Entity info still shows the visible color as assigned to back face.

BTW if you push first and then pull you get a similar result but the colors are reversed.

This certainly seems to indicates that the internal definition of front/back faces is fungible as you make manipulate the geometry of your model.

-louie