The Use of Colors in Solid Modeling

MLombard
Retired

The use of color in CAD has evolved over the years. Early versions of CAD, of course were whatever color the CRT created, usually white or green. In more sophisticated 2D, we had colors for different layers, and each part was on a different layer in an assembly drawings. Then we graduated to 3D CAD and we had seemingly random colors for parts, and sometimes features. Sometimes we use our 3D models for analysis, where results are reported by color, and so a plastic part reports draft by coloring faces. Next we enter the photo-realistic phase of solidedgecolors1.pngCAD, and colors are assigned by material.

 

On top of the different ways that we as users make use of colors while modeling, the software also changes colors to help denote selection, active or inactive, construction, types of features, sketch states or various interface elements.

 

Using the Color Manager (View>Style>Color Manager) you can assign textures or colors for different types of features such as construction (surface bodies), threaded holes/rods, weld beads and curves. This can be useful when you have to mate threaded holes to other parts quickly, or identify curves as different from sketches or model edges.

 

I have a couple of different ways I like to use colors in my models.

 

Random Part Color

 

This is probably my most commonly used method. I start out assigning materials to parts, but because I want to be able to distinguish one part from adjacent parts, I assign different colors.

 

To me, and I know I’m gonna step on some toes here, but the material = color is the most unimaginative way to assign colors. It makes it more difficult in an assembly cutaway view to see when parts are overlapping, or touching.

 

Plus, I like to use the part color for the wireframe or edge color, with hidden edges being of course dashed. Visualization of assemblies using techniques you can’t reproduce in real life using either wireframe, transparent, or cutaway parts is part of the magic of CAD.

 

solidedgecolors2.pngRendering or Color By Material

 

When you’re setting up a rendering, you are probably going to want to use the method I just got done mocking as the least imaginative method – color by material. Still, sometimes you have custom materials that you might like to use for rendering to make the visuals just a little more tantalizing. In most computer generated renderings, reflectivity is generally set too high to make things look realistic. There is a definite difference between a “cool” rendering, and a highly realistic one. Realism often involves imperfection, which is a definite weak point of CAD-based rendering systems, and this Achilles heel can also be one of the tell-tale traits that people use to identify CAD renderings from real photographs.

 

Setting up CAD models for rendering could be its own series of blog posts. The requirements of a rendering are often so different from the requirements of a manufacturing model that many folks who do renderings save out the assembly as a copy so the different requirements don’t start poisoning one another. For example, a rendering assembly should usually have some sort of size reference in it. Something commonly identifiable such as a coin, a pencil, computer mouse, or something along those lines. You might not want to have the same sort of stuff in an assembly you use to make assembly instructions.

 

Sometimes I would color by material and use subtle differences in shades of gray to differentiate between parts.

 

Color by Process

 

I’ve seen companies require users to color parts by process. So all sheet metal would be one color, injection molded parts another color, and purchased parts another. To me this might get a little tedious while designing, but certainly for the manufacturing or purchasing folks, seeing models represented in this way would be very helpful.

 

solidedgecolors3.pngColor by Author

 

In a highly distributed design team where you have many different people working together on parts from the same assembly, it might be useful to assign part colors by author. It would be even handier to be able to switch quickly between these color schemes.

 

Done/Not Done

 

When you’re going through a large assembly, adding detail to a large number of parts, sometimes it may help you keep track of where you’ve been and where you have yet to go by using colors. Green parts are done, and red parts are not.

 

Faces and Features

 

I’ve been in modeling situations where one face acted as a reference for another set of faces, and it always helped to denote that face with a special color. Such as a face that establishes the direction of pull for an injection molded part, or a special hole that is used to locate a set of other parts in the assembly.

 

solidedgecolors4.pngThis is one function that has a special setting. If you look in the Color Manager dialog, shown at the top of this article, the Show Part Face Colors setting enables you to use the overall part color, or the individual face colors.

 

And while we’re here in this dialog, let’s mention also the option above the face colors option: Show And Allow Assembly Style Overrides.

 

Overrides can be a complex issue, where you have various levels of hierarchy in your parts/assemblies, and colors assigned to various levels. Such as assembly occurrences, bodies, features, faces, parts, and so on.

 

So what’s your favorite way to work with colors in Solid Edge? Do you have any additional tricks we haven’t mentioned here?

Comments
Siemens Phenom

Just to add to what Matt wrote, when it comes to selecting colors for solid objects, particularly if they have any sort of rounded or freeform shape to them, avoid using fully saturated primary colors like Red, Blue, Green, etc.  While using these colors for purely wireframe situations may be OK or even preferred, for solid models, they tend to not do a good job in helping the user get a feel for the actual shape of the model.  What you need are colors with a certain amount of 'White' in them so that there will be highlights on the body where it curves and the light reflects even if it's not a rendered image but simply the while working on your model in a shaded display.

 

You can actually see what I mean in Matt's 'Pressure Washer'.image above.

 

You will note that for those parts of the model that are Gray, it's very easy to see the shape of the bodies, while those where the nearly fully saturated Red color was used the shape of the parts are less obvious, even to the point where some of the frame doesn't always look like is was fabricated from round tubing, at least not as a result of any highlighting effect, unlike what you see with the Gray hose and metal wand.

 

Anyway, I thought that little bit of experience would be beneficial to the readers.

 

John R. Baker, P.E.

Product 'Evangelist'

Product Engineering Software

 

SIEMENS

Siemens Product Lifecycle Management Software Inc.

Digital Factory

Cypress, CA

Esteemed Contributor

Good stuff Matt,

 

Further....sometimes we've needed to apply [via Part Painter] different colours that occur on part of a continouous face, or even spanning sections of multiple faces.....a good trick in this case, is to project [or wrap] a sketch to the face[s] as required, and run the "split" command on the "Surfacing" tab, under the Modify Surfaces group.

 

Such as the bitumous paint to the "in-ground" portion of this traffic signals pole.

[sorry, not the best image,...was the first example I could remember where was]

 

TP6 [AC-GPJUM] [Img-005].png

 

Enthusiast

It's been long time since I post but this one catch my attention.

 

Many time we look at a colors from the render point of view and many will find this cute to see good looking colors/texture and will also see this as a selling point.

 

However if you look at colors from a functional point of view,  as example when doing plant design. Colors sunddenly become functional rather then just accessory. They became as important as having the Save command :-).

 

So if I look back at the article section name Color by Process this section alone could be exapand to make the entire article.

 

In plant design we have multiple discipline, Mechanical, Structure, Piping, Instrument, Electrical, Civil etc.... to name just a few.

 

Just for piping color coding pipes and all the components by fluid type make a lot of difference.

 

Then you have structure where steel and concrete need to be visually identify. In steel you have red steel, versus steel to be manufacture, steel by contractor versus steel by our designer versus vendor (frame of an equipment). Beam versus colum versus brace versus......

 

Mechanical discipline you probably want to color code the equipment base on area, process, discipline etc....

 

And we can talk about safety zone versus maintenance zone....

 

To put a cherry on the sundae as the design of the plant evolve (progress) so the color distribution need to adjust, helping discipline leader/project manager to see how things progress.

 

So colors when you display/manage the right one in the right context, those colors can worth more than the price you will sell your product.

 

If someone is in need to program something to help manage colors here a good challenge for you :-)

 

Phenom

Another factor apart from shininess, reflectivity and white balance is transparency.

I got an opportunity to see this being commonly used when making operation manuals and assembly instructions when placement of a part needs to be shown in context of others which may be totally enclosed within larger parts.

 

Solid Edge supports this with glass and clear versions of standard colors in the Part Painter.

 

grinder.png

 

As for using colors for differentiation, another common use is between wet and dry faces of submersible objects in which few faces will typically be exposed to an external medium like oil or water are painted with one color to differentiate from the rest. Eventually the surface area is calculated. This is closely similar to what Sean illustrated.

 

Though still done manually by experienced designers, this poses a huge scope for some fully or semi-automatic method to be devised.

 

Phenom
Great read Matt.... I think you hit upon a very important issue with 3D CAD. However having said that, what it also does is point out just how BAD Solid Edge is to deal with when using colors/materials. I've spoken many times about how antiquated SE is when it comes to handling colors of parts, and representing materials. Especially when they populate different Assemblies or are sent to someone else. First off, the dialog boxes are stuck in the 90's. Defining colors by a "name" in 2015 just seems so quaint... like MSDOS V1.0 with it's 16 basic colors. Just look at your first image for "Color Manager" That hasn't changed in 10 years, and it still confuses me as to it's true purpose. Does it affect the Part, the Assembly or the default? And is it just this particular Part and/or Assembly and/or does it carry over into other assemblies if used again. I wish that all edits to colors, that you were given and option to update the library or keep it specific to the part.... the Colors/Materials should be imbedded in the parts and can override the stock library. Anyway I don't mean to be a wet blanket on this, so I won't go on. My point is that this article is VERY important, and I only wish development realized this and tried to make using colors a little less of a hassle. Bob
Siemens Valued Contributor

Nice post, Matt.  

 

In Manufacturing, we use different colors on solid bodies to represent different machined areas. For example, in mold machining, yellow faces might represent runners and risers, green faces might represent parting lines, and gold faces represent the actual cavity of the mold.  Having that differentiation allows us to automate face selection for certain types of machining.  Taken a step further, Feature Based Machining systems can create different machining strategies for different color face groups.

 

One thing that I have struggled with is the nuance of colors is never enough.  I generally can only use one shade of each color.  I'd like to see more textures applied with the color (like the Aluminum color in Solid Edge).

Solution Partner Experimenter

Interesting post.

 

I also have the feeling that the use of colors in the Siemens sister product NX is more powerfull. For instance i have seen the possibility to color parts based on different parameter sets. So you could have a parameter set which is used to color faces for machining purposes (ex.milled, turned, grinded, edm-ed) and another for accuracy purposes or quality check. Selecting one of these parameter sets colors the part accordingly.

 

Not sure how this was done in NX but would be nice to see this kind of functionality in Solid Edge.

 

Thanks for bringing this point forward !

Creator
Creator

jchanterie

 

I think you refer to HD PLM something I believe has start three years ago. That woudl have been nice if this vcould have been find it way to the Solid Edge core product.

 

http://www.lifecycleinsights.com/technology-providers/hd-plm-siemens-plm/

 

From what I can understand this has/will evolve to what is now refer to as industry 4.0. HD-PLM is a block to get there.

 

https://www.youtube.com/watch?v=HPRURtORnis

 

I probably round the corners a lot, but i think people will get the idea.

 

Forget to mention here what is look like today

 

http://www.plm.automation.siemens.com/en_us/about_us/facts_philosophy/smart-innovation-platform/

 

 

 

 

 

Retired

Another use of colors on models that I had forgotten about is tolerances. When sending plastic parts to a mold maker, sometimes in addition to a simple drawing, I would color faces for special tolerances.

Phenom

So I thought I'd add this to the story....

 

I had to open a recently finished Draft file for a customer question and lookie here... ST7 decides to make the 2 Stainless Steel side panels out of wood.... Why in God's name does this stuff happen?

 

      In the assembly

                                              

wood ss 2.png  wood ss 4.png

 

But inside the part

 

wood ss 3.png

 

BUT this is what see in the Draft file:  WTF is going on here?

 

wood stainless.png

 

Will someone PLEASE in development make "Colors" inside Solid Edge more consistent and less of a hassle.

 

And notice how many **bleep** screens I have to go to just to see if everything is correctly set. And if I did happen to have something amiss, think about what a PIA it is to correct.

 

Again when will color usage in SE join the 21rst century?

 

Bob

 

p.s.   And can someone tell me what this is all about? If I set the Assembly to "Options Color Set" If it's so the user can see what's active or inactive, then why is this Command so buried, and seemingly useless?

 

wood ss 5.png

Phenom

Another application or selection criteria for colors in plastic parts design is protection against damaging effects of sunlight, a plastic product designer told me.
 
The wavelengths of light over the range 290 to 390 nanometers which is in ultrviolet (UV) region are most destructive to polymers degrading them by direct rupture of chemical bonds.
 
Some colors reflect and scatter light waves while still others absorb UV radiations and act as screening agents.

 

Thus colors help in preserving a part's physical integrity by reducing cracking and loss of tensile strength is what I learnt from the plastic part designer during a casual chat. So choice of colors in parts in an assembly are based on the these factors - where they are located in the assembly - facing externally or obscured by other parts.

Dreamer

Just to say I agree with BobMileti, as a long time SE user the way colours are to be used in SE is cryptic. Has been for a long time, for eg., listing "colours" by a "name" in the Part Painter dropdown without a least showing what the colour looks like is not only counter intuitive - it wastes time! If you have 10 different "named" colours for Green you would have to apply each one to see if you remembered correctly if it is this "green" (for example) that you wanted to use.

The Colour List dropdown should AT MINIMUM show one what the colour would look like?

But what about real world colours!?
On occasion we have parts/products epoxy coated, and every single Epoxy Coater we have worked with refers to a RAL Colour Palette (http://www.ralcolor.com) when it comes to choosing a colour for the objects.
Why can't SE not have multiple types of Colour Palettes, for RAL Colours, Pantone Paints, or whatever international paint/coating standards there are for colours?
How about recruiting major paint/coating manufacturers to have their standard paint colour Palettes added to Solid Edge, just like you would specify a particular part by number? When it comes to painting (epoxy coating), one can then simply specify, use number xyz from whatever company supplies the paint/coating that was in the colour palette?

A final point to consider, assigning Faces Styles to SE Templates has its uses, but if one wants to update or change a specific colour, propagating that change(s) across multiple templates & hundreds of individual parts (since the Faces Styles is imbedded in each part file) is beyond cumbersome.
The Faces Styles should offer a "Global" settings file as an option so that one can create a master list of colours with multiple palettes (like for the RAL/Pantone Colours mentioned above) that can be saved, and referred to by all users across the network to standardize colours.

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