October 25, 2026  Projected Light Dispersion -- SketchUp Make, and Twilight Render Extension (Hobby Version)

The hobby version (free version) of Twilight Render Extension that can be installed in SketchUp Make does not include the options that will separate colors in the visible spectrum.   It can be used to disperse colored light, however, involving rendered light passing through rounded and angled flat glass objects.

I have had limited success with today's three-layered prism made up of:

1. Translucent glass on the outer layer,

2. an air gap in the next layer,

3. and a solid reddish liquid--water--(Twilight Render Extension Material setting) for the inner core. 

An Emitter light source was selected from the Materials Editor of Twilight Render, as well.  The Lumens were turn up very high to 200,000 Lumens in order to achieve a caustic effect (that I know very little about).  Other important settings included:

• Hemispherical Sky setting

• Sun disabled

• Boxlighting option with an Emitter for the prism's light source

• Brightness setting of 4 gave the best results for the exterior (see below).  

There are no doubt better ways of doing this.

Here's what I've rendered thus far (a work in progress).  Click this link to see the SketchUp Model,  Prismatic Light Dispersion  (non editable in SketchUp Viewer).

October 18, 2026  Projected Light Dispersion -- SketchUp, Twilight Render, GIMP, and ChatGPT

Today's SketchUp model represents an experimental closed environment where four light beams are projected onto a screen using Twilight Render Extension light Emitters.  I have exported images of several projections:  The first image shown is a cleaned-up version taken within the sealed (darkened chamber with an internal Camera view -- forward view.  The other views were taken from at an angle through a side opening in the chamber with dimmed external brightness.  They also show the projected light beams, but due to perspective they are more difficult to observe.  All scans were very dim (see image 5).  GIMP was used to increase  exposure levels of each rendering.

Instead of of using Twilight Render Extension's post processing option to increase exposure, I elected to Use GIMP's Color/Exposure options, that in my opinion were easier to apply.  Lastly, ChatGPT's image generator was used to emulate a more vivid image for the front view rendering. 

Due to  lack of expertise on my end, all versions were very dim and blurry.  I used only the lowest Twilight render setting for all but one image to render each image due to time constraints.  The initial rendering required 90 minutes at a higher level with no visible improvement in quality due to either low-light conditions, too much light, or incorrect focal point.  My main goal was to develop a working model that would project light at whatever quality.  The bugs can be ironed out later.

The instructions given to ChatGPT for the first projected image shown below:

"Please improve on the clarity of the following image.  It represents a projection of four isolated beams of incandescent light focused on a flat gray background screen. Clean up some of the blurr to better define each light and shown where each circular light beam has overlapped and merge.  The 4  lights originated from separate isolated light sources that were horizontally and equal spaced and each were projectected through a circular aperture.  The camera was position between the center two pinholes where the light originated.  Please processes the image as it is seen above.  Some blurr should be retained to make it appear realistic."

Also shown below is a cutaway image of the SketchUp Model and a Link to SketchUp Viewer that shows design of the enviornment for producing the light enclosed in a 10,000mm x 10,000mm cube.  

• The front interior is the projection Screen--painted a flat gray.

• Half way behind the screen is a wall containing four horizontally positioned pinholes, each with 350mm circular apertures.

• All walls were painted a flat darkgray or nearly black.

• Behind each Aperture within a darkened cylinder are Emitters (lights) within each tube consisting of a circular flat disk that was eventually painted with a Bright Emitter light material during the Twlight Rendering phase--I cannot  show this step because it is not part of SketchUp viewer's capabilities.

• Each Emitter was positioned inside an adjustable cylinder with interior and exterior paint--again flat dark gray or nearly black. 

The image consisting of four beams of light is projected upon execution of Twilight Render Extension (hobby version) whose main purpose is to convert SketchUp Make (free version) models into photo realistic images.  For demonstration purposes this setup was adequate (not perfect) for today's project.

Perhaps in the real world, four bright penlights focused inside a cardboard box in similar fashion would have produced a better image with a smart phone  camera creating an image or video placed inside the darkened box and focused on one wall/projection screen painted a flat or matte gray color.

The purposes of this demonstration was to view light as it fans out or disperses, merges, and interferes with neighboring light projections.  Similar simulations represent classic preludes to explaining Quantum Entanglement, where a photon is broken apart (either naturally or in a lab) and two new lower energy photons go their separate ways even though the pair share the same quantum state.

Depending on its settings, Twilight Rendering extension may be able to generate photons, but for this demonstration, I assume only visible light is being rendered.

From other SketchUp projects utilizing Twilight Render Extension, I discovered it was possible to render controlled magnification and prismatic color separations.  Twilight Render Extension's image generator contains the mathematical formulas for optics.  This is the extent of my understanding.  For further information, consult AI apps or Twilight Render Extension literature.

Click this link Light Dispersion that will open SketchUp Viewer in your browser (uneditable).  No rendering of emitted light can be performed, however.

October 13, 2026  Wooden Barrels -- SketchUp, Twilight Render, and Gemini

SketchUp, Twlight Render, and Gemini's Photo realistic version incorporates  barrels.  See images and links below:

October 12, 2026  SketchUp Thread Review -- Five-Helix 7/8" UNF Thread 14 TPI

Here' are Links to Trimble's online SketchUp Viewer that opens in your browser: 

Part I   UNF 14 TPI Helix and Five Helix Thread Profile Design

Part II UNF 14 TPI Thread

The 3D SketchUp models  cannot be edited with viewer;  however, you can take measurements, zoom in or out, and view from any angle.   I have used a 25 segment circle with a diameter of 8,750 mm diameter.   The simple math works out great when using a 25 segment circular base with a scale where 1" is represented by 10,000 mm and a bolt diameter of 8,750 mm.

The math is kept simple when using my triangular alignment guide design shown in Part II.  It is positioned at the bottom of the thread spiral and is created using only lines extended from the thread profile and circular base at the bottom as a reference  (see Part II).

The traingular shaped alignment guide is painted red so that you can't miss it.  It is used in the final step for shaping the thread, but it is setup a few steps before the actual deformation of the thread surface.

The most important part for applying this method is to follow the steps in the order they are shown.  For example, without aligning the completed thread profile, you cannot establish the thread depth unless you apply unnecessary preliminary math involving geometry--and then trying to apply decimal fractions may prove to be a futile attempt--let SketchUp do the math internally using the Divide and Mid-line options provided and copying and pasting the line segments it creates whenever needed.  Don't rely on typing long and/or turncated decimal fractions for the accuracy that is required for this project. 

Here's  why: 

Internal Floating-Point Precision

SketchUp does not calculate divisions using the fractional display limitations you see on your screen. It uses 64-bit double-precision floating-point numbers for its internal database.  For additional information, inquire using AI Overview.

Once the thread or bolt, etc. is finished, it can be scaled down to a 7/8" inch diameter with an easy, one-step method using SketchUp's Tape Measure Tool.  It is shown here in its large metric version for ease of access and convenience.  Everything scales down proportionally when needed.

October 1, 2026  SketchUp and GIMP Drawing ➔ ChatGPT

Today, I tried something a bit different by creating a photorealisic image from a SketchUp and GIMP image without lined edging.

Originally, the image below was an old SketchUp drawing that was created in 2013, with blue filters applied a year or two later with GIMP.

This project represents another way to improve upon all  of my earlier SketchUp exported images.  One limitation is that these renderings will lack the detail compared to those displayed in September's post.

The computer monitor I used in 2013 was narrow and the exported SketchUp images from that era were almost square (See Digital Art, archived Digital Art page 1 links in the left sidebar).  To provide a more panoramic image, I have cropped much of the white space from the bottom of the winter scene.

If more image transformations are completed from this early set of images, all will require either cropping the top, bottom or, a little of both to fit the updated image dimensions currently in use.  Others images may need to be selectively cropped using only the best part.

For now, I'll begin posting rendered photorealistic image below followed by the SketchUp and GIMP version from long ago.  

September 26, 2026  Gemini and ChatGPT -- Rendering SketchUp Drawings Activity

If you have not used Gemini or ChatGPT to convert drawings to photorealistic images, here’s your chance.  When using a browser on the computer, you have access to the first tier (free version) of Gemini and ChatGPT that provide ample opportunity to render photorealistic images.

Before getting too far into the discussion, I'll clarify how each image conversion is done:

• First, the SketchUp drawings were exported from a 3D SketchUp Model.  (Actually, any digital image could be used.)

• Next, the individual images were uploaded to an AI app--either Gemini or ChatGPT--along with instructions on what was to be added and that it should be rendered as a photorealistic image.

• The AI app provided its best version within a few seconds.  If there was something not quite right, the instructions were modified and submitted again.

• Sometimes minor issues were corrected manually with a photo editor such as GIMP or PhotoShop after downloading the photorealistic image.

I will provide you with links to a few SketchUp images that you can download and then upload to Gemini or ChatGPT for converting them to photorealistic images.  You will need to provide a prompt to insert any details that you would like to see in the final version.  Most of these prompts will require an instruction to "stock the shelves."  After Gemini renders its version, download it to your computer.  If you want to edit it further with Photoshop or GIMP, for example, convert it to PNG format after opening it in the image editing application.  For example, the Cloning Tool seems to work better using the PNG file format in GIMP instead of Gemini's default file format.

Click here For the complete Instructions and Image links, Instructions and Links, (PDF file, 618 words, 8 pages).

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Footnotes:   1950s Shopping:

Mid century shopping in small towns was a bit different in the old days.  There were no shopping carts.  You'd carry and then set the items to be purchased on the counter near the cash register.  The clerk would ring up your bill and bag your groceries.  Usually two large paper bags was a maxium purchase (unless there was a watermelon or a gallon jug of vinegar.  One bag under each arm was it.  If more was needed, another family member helped you shop or you'd return to the store.

There was no loading up  dozens of plastic bags like today.   Hamburger and sliced ham, bologna, etc., were cut and then wrapped in butcher paper, and tied with store string--no plastic or vacuumed sealed packaging.  Frozen items were usually boxed--sometimes, frozen fish were sold whole and unscaled.  Cereal and cans of soup, etc., were quite similar to those of today (but larger).

On the other hand, soda pop came in glass bottles that were much smaller--10 oz. was considered large enough.  Coke was good and Rootbeer had a fizz.  Frozen ice cream was really ice cream back then.  Candy bars were bigger and tasted better.

A generation before me, barrels of crackers were common and a penny would buy you a bag of hard candy.  That penny seems to be worth about as much as a dollar will buy you today.

People complained about prices much like they do now.  Complaining and Inflation have kept pace with each other.  Things gradually transitioned into what they are today.

September 13, 2026  Gemini -- Compilation of Digital Art

After rendering more than a hundred images similar to those shown below, it's time to take a break.  The subject matter during the past month and a half was derived from a large 3D SketchUp model of my hometown that I had created a decade ago.

These stylized views were rendered by Gemini AI based on uploaded images from the model along with detailed instructions to achieve the effects that you see below.  The bulk of the work posted below dates back to late July.

Images illustrate what the town looked like in the 1950s and early 60s with some scenes containing structures that were standing in the 1930s. The small town's business district is at the south end of Main Street--these can be viewed extensively in earlier posts.  The churches are shown separatetly.  The North Main pictures include  the school and views of the residences along both sides of Main Street.

The small prairie town, like most, lacks grandeur--no palaces, castl,e or anything else remsembling awe-inspiring vistas.  What makes it worthy of catpuring on canvas or on screen is how utilitarian everything is and how, street by street, it all fits together.  Setting the mood by changing the natural elements--daytime to night and varying the seasons--adds interest, reality, and a feeling of being there.  Open the PDF links in this series of ten posts and zoom deeply into the images.  At 200--400% you can then scroll horizontally and sometimes vertically.   You'll get the idea.

A few other variations were posted in the Photography section (see left side bar) because they were transformed from old photographs rather than from SketchUp exported images. 

The emulated art gallery below is a culmination of many enjoyable hours of doing what I like to do best.  Here's the Last image in this series.  For an enlargement click here:  Compilation of Digital Art,  (PDF file, 242 KB, 1 page).

September 12, 2026  North Main Street, 1st & 2nd Avenues, and the Stockyards -- SketchUp, Gemini, and GIMP

Here are 49 more scenes following the same format as previous posts.  Each scene shown below has a day and nights/snow/rainy/foggy, etc., version in addition to the original SketchUp exported image from the model.  More information about the SketchUp model has been previously discussed.  I, alone, possess the original SketchUp Model to serve as evidence, that I am the true creator of every image generated and posted in this series.

Lastly, there are several 3D exports in wireframe and monochrome views to illustrate the elements within a SketchUp model.  This is the bones/DNA of all of these images without "Shading and Textured" faces applied.

Here are the above mentioned images that can be either downloadeded or opened that provides a close-up look:  North Main and 1st and 2nd Avenues  and Stockyards, (PDF file, 3.03 MB, 50 pages).

September 10, 2026  Residential Neighborhoods -- SketchUp, GIMP, and Gemini

Here are two scenes selected from my SketchUp town model that was completed in 2016.  Since AI is at everyone's fingertips, it is very enjoyable to make use of it by transforming exported images from a basic 3D model into photorealistic pictures.  Today's street is a walk down memory lane.

The scenes below contain a family out for a stroll.  They are shown on a street with an Odd Fellows Lodge and two homes in the background that were built in the early 1900s.  These images capture the street in the mid 1950s.

The prompt given to Gemini AI is easy to explain.  Just describe the people to be inserted into the exported image from the SketchUp model and whether you want it ato be night or during daylight.   Also, describe the season and weather conditions if you want.   Gemini knows what to do with an uploaded images after you provide a few details.

For a close-up look, open or download from this link. Click here:  Rendering Neighborhoods,  (PDF file,  742 KB, 9 pages.)

September 7, 2026  Spring Basketball -- SketchUp and Gemini Imagery

In the 1950s, it was common practice for high school coaches to take down the hoops from the basketball court at the end of the season to signal players that it was time to move on with spring training for baseball or track.  That didn't dampen the spirits of the neighborhood kids.  The images show backyard activity as soon as the snow began to melt.

Coincidentally, the large building in the background (see below) doubled as the school's basketball auditorium.  It was a multi-purpose facility that got plenty of use -- roller skating, dances, school carnivals and other larger gatherings.  The kids looked forwrard to playing indoors once practice resumed in November.

For larger and downloadable images click here:  Outdoor Basketball, (PDF file, 625 KB, 6 pages).

September 6, 2026  Image Transformation Process --SketchUp Model to Stylized Photorealism

This post includes the churches from the small town featured in the prevrious post.  They represent those in use during the 1950s.  A new church was built in 1961 that replaced the white church (see below).  There are three images of each scene that illustrate the creation process in reverse order--beginning with the the highly stylized image back to the original 3D SketchUp Model Export.  The photorealistic and stylized versions were  rendered with Gemini based on the prompt I included along with each downloaded SketchUp drawing. 

I have chosen elevated camera angles from the 3D model in order to show off roof lines and other elements of the town in the surrounding area and in the distance.

Also, Gemini embellished the stylized versions based on my very brief instructions.  For example:

 "Create a detailed photorealistic image of the attached rendering that emulates .  .  ."  You would enter your style preference here, create a hybrid, or use your own.

Please excuse errors in detail.  Most of these were modeled from memory with only a few original photos available to serve as a guide.

For larger and downloadable images click here:  Town Churches, (PDF file, 1.18 MB, 17 pages).

September 4, 2026  SketchUp Model Image -- Gemini Gray Scale Rendering--Dust Storm, Nostalgia

There's just one image today.  The background is lost in the blowing dust as would be expected with roads covered with a mixture of gravel, sand, and clay that has become very dry during a drought.  In addition, there would also be a mixture of airborne topsoil blowing in from hundreds of square miles due to the dry climate conditions, the strong winds, and over tilling.

Farming practices have improved since the early days, but a storm of this type developed locally this year that reduced driving visiblility to zero and in spots resulted in substantial drifting of prime agricultural topsoil along highway ditches.

The original image for today's project was taken from a collection of exported pictures created from a large SketchUp model of an entire small town.  These can be viewed in various stages of completion in Digital Art 1 and 2 linked in the left sidebar.   Gemini was prompted to convert the image to gray scale and to create a hazy background caused by the blowing dust along the streets and in the sky.

The original SketchUp model was begun in 2013-2014.  Who could have imagined back then that exported images would later be transformed into photorealisitc likenesses.  This has been a perfect ending to a project that required months to complete so many years ago.

I grew up along the street pictured below.  Different aspects of it are etched in my memory.  Today, the only remnants of what is in view below are the roads (now paved), the first building on the right, and the street lights and power poles.  The buildings have either been demolished, or were destroyed by fire.  A few have new structures in their place.  It will never look like it had once did.   The missing wood frame and brick buildings would now be well over 100 years old.  These photorealistic drawings will keep the memories alive.

September 2, 2026  ChatGPT's Re-interpretation of a Photorealistic Image

Transformed images (SketchUp model to photorealistic image) posted during the past two days have been inspired by a variety of notable works with contrasting styles.

Click here to zoom into the ChatGPT version:  Grandstand Transformations, (PDF file,  532 KB, 5 pages).   Note:  Download and/or view the PDF version of the image files with Zoom options.

August 31, 2026  Gemini's Re-interpretation of the Old SketchUp Project

The first set of twelve images were selecetd from the  July 23rd Photorealisim project (see below).  Gemini has transformed these images to appear fanciful and almost surreal.  Many of them are shown in a wet and lush environment.  Gemini was asked to transform these images by applying various contemporary artistic and photographic styles.   Application of these styles includes an illuminated sky, mountains, a few new structures, window scenes, bunches of floral vegetation, signage, and multiple lightsing sources everywhere.  In some instances these interpretations contain harsh or bold color combinations that cannot be described as photorealistic, but only realistic unto itself.

In reality, the townsite is located on a flat prairie with not a hill in site. These modifications create a fanciful, cheerful , and cozy atmosphere.

For a closer look you can view the twwelve images again using the zoom-in feature--click here:  Gemini's Digital Image Transformation, (PDF file, .99 MB, 14 pages).

Link to Here

July 23, 2026  A New Life for An Old SketchUp Project

Today, I resurrected some old images from Digtal Art, page 2 (see left side bar).  The images had originally been exported from an old SketchUp model (2015--16) and then edited with GIMP.   Along with a few short instruction Gemini did a good job adding more photorealism.

There are potentially thousands of images that can be rendered from the digital art page 2 gallery.  With access to the original SketchUp model and the ability to modify it, I have litterally an infinite number of scenes and camera angles from which to chooee.

For you, however,  all you need to do is download or print screen one of the 2D graphic images from Digital Art, page 2  (Or one that has also been edited with GIMP) and ask Gemini to create a photorealistic image from the drawing.  Give Gemini a few specific instructions that you would, or would not like to see. In a few seconds you'll have your own customized copy that is truly unique.

Lastly, there were quite a few details that I got wrong in the original SketchUp model of my hometown, but the rest is recognizable if you're an old-timer like myself.  Three decades of structures, cars, and trains (30s through 60s) tend to overlap in many scenes.  Note, I also used GIMP photo editor to fix a few spots that usually came up in the background where Gemini couldn't quite figure out what was what.

Here are sixty-three examples of Gemini's work that focuses on a small town's Main Street, Depot, and Baseball Ball Diamond as seen in the mid 1950s (or earlier) through the early 1960s:

You can download a copy of the above images and a few more interior views by clicking here:  Digital Photorealistic Album 2026, (PDF file, 13.6 MB, 64 pages).

The advantage of the PDF format is that you can zoom into specific areas for a closer look.  Many of the images retain reasonably good quality up to 400% mangnification;  however, some will pixelate and rendering errors become more evident.  I have manually edited many specific elements with the GIMP Photo Editior that Gemini had misinterpreted.

Before the above mentioned modeling project was completed in 2016, there was an earlier series of gif images created from my initial 2013 SketchUp model with GIMP image light and filter edits.  You will see see a crudely drawn set of images using a more primitive style.    Examples are found in Digital Art, page 1 that is linked in the left side bar.

A few structures from the first model, however, were good enough to be carried over for later versions that followed. Thanks to AI, rendering tools for the general public have improved since then.    Click Here.  This GIMP animation plays on a continuous loop so close the tab on your browser when finished viewing.

July 22, 2026  SketchUp Model with Gemini AI Enhancements

Below is an Hour Glass that was rendered from a SketchUp image uploaded to Gemini and is based on the following instruction:

"Please use the following design to create an hour glass which is placed on an old hardwood table in a 17th century sitting room. There is glass and sand within the wire lattice work that is currently green.  Change the green to a tarnished silver color.  The upper and lower gold-colored sections should be pollshed brass.  Both ends are made of shiny hardwood."

To see how the initial model was made, Click Here to view it with SketchUp Viewer.  See images below.

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Comment:

The October 8, 2025 Post in SketchUp Projects V illustrates equally elaborate Gemini-generated images created from line art -- various views of wire frame SketchUp models accompanied by detailed prompts. Click here to view Contemporary Arizona Homes and Lifestyle.

July 15, 2026   Review Thread Design Sequence -- Five Helix Thread Design with SktetchUp and Twilight Render

Today's project is a review of the Five-helix Method for drawing a 1", 8 TPI section of thread.  The finished model was rendered in SketchUp Make with Twilight Render Extension--Hobby Version.  The model's dimensions have not been reduced to actual scale to allow greater precision while drawing.

Click the following link to view an uneditable version of the model using SketchUp Viewer:  Coarse Thread Review.

The Viewer version illlustrates all preliminary steps in the creation of the model.  The first rendering below was created with Twilight Render Extension and does not appear in SketchUp Viewer in its rendered state--it is a separate file, as are the 2-D graphics renderings that were exported from SketchUp Make as jpg file.

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