Over the time I have been 3D modelling, the designs I enjoy creating the most has to be Mechanical and hard surface models. As such, I have been wanting to learn the various techniques available to create good hard surface models. And now I have found something I would like to try out.
High Poly (Hard Surface) Pipeline
After searching online for reference material to create a pipeline for the assets i will be creating, I found a few examples that could work.
Adam Dart, a member of Team Junkfish, posted devblogs on his work in the development of the horror game Monstrum, some which detail how he creates game ready hard surface assets. In the specific blog I read, he created a pair of headphones in Maya. While he uses supporting edges and a Nurbs smoothing method to attain the final high poly and low poly shape, I will be using the Chamfer tool and a Turbosmooth modifier to achieve the same results in my work. while this workflow primarily fits in the modelling segment, it helps prepare a mesh for sculpting.
A post on CG Masters, written by Guilherme Henrique, shows a complete pipeline with a full example in the form of a weathered Tombstone. The pipeline itself is similar to pipelines i have worked with in the past, but includes Sculpting in the process as a means of adding extra details and damage in the texture mapping stages. Overall i am likely to practice my pipeline with the tombstone, although i will use a different design.
On a website called Instatuts, Angel Trudeau wrote up a workflow they used to create a low poly shotgun (1500 polys) and two variations of it (A double barrel and sawn-off double barrel shotgun). The primary difference between this example and others is that it does not use PBR textures, and instead used a diffuse, specular and normal map, of which the normal map was baked from a high poly sculpt
Here is a pipeline i have created based on the research above:
Stage 1: Gather reference
A simple step, all that is needed is to research the concept/s that are going to be modeled. This would be in the form of concept art, modelling sheets and similar items but it also includes reference images.
Here are some reference images for a cannon I am planning to create for this project:
Stage 2: Modelling
Using the reference material gathered prior, model the base-mesh for the project. This step is quite varied a just about any technique or method to create the model can be used, from shaping a cube to extruding planes. Just about anything goes to put the model together. It is also important to prepare the model for the next stage – Sculpting. This will be done by creating a unique save file of each mesh and normalising the polygons in it, by adding edge loops until the size and density of polygons are more or less equal.
Stage 3: Sculpting
Once the model is prepped, Its time to Sculpt! Using various tools, such as imprint and knife, Details can be sculpted in the mesh. Some images that are specifically created for sculpting tools can speed up the process immensely. This is the technique used in the tombstone tutorial to generate damage on the lower section, making it seem that the top layer has broken off, revealing brickwork underneath.
Stage 4: Retopology
Once the sculpt is complete, it is time to retopologize it. In short, there are 3 ways to do this. 1; Retopologize the model by hand. 2; utilize automatic tools. 3; Alter Basemesh to fit. The third option is very situational, but it can be effective in quickly retopologizing a sculpted mesh
Stage 5: Unwrapping
Simple Enough a stage. As with anything when unwrapping, There are a few main points to note when placing/making seams, such as separation of materials (I.e seperating Glass in a window) and to hide seams whenever possible/beneficial, such as in an armpit. Given i’m working with hard surfaces, I might be able to cover seams with separate elements, such as a hinge or handle.
Stage 6: Baking
Before texturing can go into full swing, a few textures need to be baked. And even before that, a cage is needed. This can either be automatically generated or formed by hand. As with most things, a cage done by hand is better than a generated one. Now with an Unwrapped Model, a suitable High poly and Lighting prepared for when it is needed, the following maps can be baked: Normal, Ambient Occlusion, Curvature, Convexity and Cavity maps.
Stage 7: Texturing (PBR)
And finally, Texturing. Just about any program, be it Photoshop or Substance painter, will do here as long as the output maps are the same. Inputting the baked maps will enhance the output textures. Speaking of, the output maps should be Albedo (base colour), Metallness, Roughness, Specular. Why these? well, in this case I will be rendering final images in Unreal engine 4, and these are the texture map types it utilizes.
And with that the project/product is ready to render and present.
Below are tools and techniques i found that will undoubtably speed up this project while potentially making the models more pleasing to the eye:
Turbosmooth, Supporting Edges and Chamfers
– During my research, i found that using a turbosmooth modifier (Or simmilar tool) can be used to quickly and efficiently create a high poly model, given the right preparations. These preparations lie predominantly within Supporting edges. Supporting edges affect turbosmooth modifiers substantially by essentially pulling the ‘new’ curves and surfaces to the ‘supported’ edge. For and example, see below;
However, as useful as this is, there are a few things that I need to be cautious of.
Most importantly of these are ‘High Valence Vertices’, vertices where more than 4 edges connect/end. These vertices cause strange results when in a turbosmooth, and are most notable when they are on the end of a cylindrical shape. For example:
How a high valence vertice is dealt with will vary, but in all cases it is necesary to reduce the amount of edges leading to the valence vertice.
Stencils and Stamps in sculpting
A neat little trick, which somehow I didn’t think of before, is to find sculpt friendly images and use them as ‘stamps’, imprinting designs into a mesh when sculpting. This is perfect fro quick Normal maps for smaller details like grout between tiles and worn brickwork. The pipeline example I found on CG Masters used a few stamps in sculpting to give the look of exposed bricks and imprint writing and an insignia on a tombstone.
What am I going to make?
Now that i have a workflow and some new techniques, its is only logical to try them out.
To actually use this information, I have created a line of goals to accomplish before the time I have to do them runs out:
1- Begin with a Tutorial:
To begin work I am going to follow the ‘Tombstone’ example that I researched. I i’ll be changing the design but this is mostly to get a better idea of how long this workflow might take. This tutorial should also help demonstrate the practices and workflows I researched, as so i can implement them on unique designs and become familiar with them.
2 – Helmet
Second is to create a simple design for a helmet, which will be a slight mix between more modern motorcycle helmets with a heavy, and kind of boxy look. It won’t be very detailed and will look like new when it is done. It shouldn’t take too long as the point of this specific model is to take what i learn from the tutorial and apply it to a unique design, before taking on the ‘magnum opus’ of the overall project.
3 – Cannon Assembly
This the the model I hope to complete, and it is going to be the most complex and intricate model I have done to date. The high poly will have each and every detail from the cannon barrel to each nut and bolt. It is likely to take the shape of early field guns which used simple recoil and breech mechanism, below is an example.
Bech-Yagher, C. (2016). 10 hard surface texturing tips for beginners. [online] Creative Bloq. Available at: http://www.creativebloq.com/3d-modelling/10-hard-surface-texturing-tips-beginners-51620208 [Accessed 27 Feb. 2017].
Bradley, J. (2017). 3ds Max: Hard Surface Modeling Basics. [online] Lynda.com – from LinkedIn. Available at: https://www.lynda.com/3ds-Max-tutorials/3ds-Max-Hard-Surface-Modeling-Basics/479385-2.html [Accessed 27 Feb. 2017].
Dart, A. (2015). Art Blog 25 – Hard Surface Modelling Techniques [Part 1]. [online] Team Junkfish. Available at: http://teamjunkfish.com/2015/03/art-blog-25-hard-surface-modelling-techniques-part-1/ [Accessed 27 Feb. 2017].
Graphics.pixar.com. (2017). Modeling Tips. [online] Available at: http://graphics.pixar.com/opensubdiv/docs/mod_notes.html [Accessed 27 Feb. 2017].
Henrique, G. (2017). What To Know When Creating Next Gen Assets : CG Masters. [online] Cgmasters.net. Available at: http://www.cgmasters.net/free-tutorials/what-to-know-when-creating-next-gen-assets/ [Accessed 27 Feb. 2017].
Trudeau, A. (2017). Pipeline and Workflow for Creating a Next-Gen Game Asset | Instatuts.com. [online] Instatuts.com. Available at: http://instatuts.com/featured/pipeline-and-workflow-for-creating-a-next-gen-game-asset-shotgun/ [Accessed 27 Feb. 2017].
Cannon Assembly Images:
Commons.wikimedia.org, username Balcer