80.lv Article: Finished Piece
Creating an Antique Telescope
In this article I will describe the process by which I created this asset, with focus on the main tube of the telescope and the texturing of it.
Before starting to model the telescope, I gathered some reference images in PureRef. Antique telescopes are a popular item listing on Etsy, so there was lots of reference showing different styles and builds for such telescopes.
The majority of the modelling process involved starting with basic shapes and extruding faces and creating loop cuts to achieve the shapes I wanted. I combined different aspects from each reference photo when modelling, so the final model is not an exact replica of any of the reference I used.
There are not too many small details on this model as the final application that I had in mind was for it to be backlit by moonlight, so the silhouette was more important to me than adding lots of unnecessary detail that would not be visible. The texturing also adds some detail to the model through edge wear and scratches. I added one level of subdivision to the model to smooth out the curved edges for rendering purposes but for use in a game or larger project the subdivision isn’t strictly necessary.
The modelling for the rest of the components was a similar process, starting with a primitive shapes, then scaling, extruding, and adding loop cuts until each part resembled the references I used.
I’m neither a big fan nor very good at UV unwrapping models. Thankfully the components of the telescope weren’t too difficult to unwrap. I marked a seam down the length of the model and a few around the circumference in several places until the UV unwrap looked more or less even. I moved a few vertices by hand to straighten out the UVs in a few places, checking the texture on the model to ensure I wasn’t distorting the texture placement.
The UV unwrap for the legs and the other components was fairly straightforward, as these parts were either more simple shapes or had seams that were easily hidden. The process was the same though. I marked seams on the models then unwrapped them, modifying the seam placement until the models unwrapped nice and flat and with little distortion.
The texturing involved building up several different textures in layers to create a more natural looking material. I began by using a polished brass texture set from textures.com for the base metal material.
I then used the roughness and normal maps from a different texture set to add more depth to the surface imperfections on the model. I mixed the base and new normal roughness maps together using a MixRGB node which allows some level of control over how much of each map is used in the material. I did the same thing with the two roughness maps but I also added ColourRamps to further control the amount that each roughness map impacts the material.
The next step was to add a dirt layer to the material. To do this, I used the second roughness texture as a mask with a ColourRamp to control the amount of dirt and how strong the dirt colour is on the object. The mask was used to mix the base colour image texture with a brown colour to create the look of dirt or grease on the telescope. Any image texture could have been used as the mask, but I decided to use a texture I already had as part of the texture set up for ease and it created an effective mask.
To create the edge wear mask I used the Bevel node and Normal output of the Geometry node and combined them using the Dot Product to find the point at which the two intersect, selecting out to sharper edges of the object. The Map Range node can then be used to tweak the black and white mask produced by the Dot Product, revealing white edges at the sharp points of the model. This produces a decent mask by itself, but it produces hard edge lines rather than a more inconsistent or patchy pattern that we might see in real life. To create this patchy pattern, I took a Noise Texture and subtracted that from the output of the Map Range, leaving a mask with more uneven edges.
This was then used as the factor by which the colour was mixed with a dark brown and the roughness was mixed with a light grey in order to make the edge wear areas a darker, more matte colour.
The final material can be seen here with the result.
I used this gold material on all of the components of the telescope. For the wood of the legs I used a simple PBR material with image textures I got from texture.com again.
I'm pleased overall with how this object turned out. The material is detailed and gives the item a used look, precisely what I was aiming for. I think it has a really strong silhouette, which is ideal for the use I have for it.