Guest post by JCSchaeffert.
Hi! My name is JC Schaeffert. I’ve been a 3D designer for 8 years, and I’ve been working as a freelancer for almost 4 years now.
Today, I’ll show you how to model and upload a low-poly 3d model onto Sketchfab. I’ll take you through the whole process, from HD modeling to the scene fine tuning in the Sketchfab UI.
This is my first tutorial, so I’ll try to be as clear as possible. The methodology I’m using for creating a model is rather common and you’ll find this workflow in many online tutorials. Hence, I’ll simply go through the main steps regarding the creation phase.
Below is the final model presented on Sketchfab.
My project was to revisit Frankenstein’s creature.
First of all, in order to design the character I draw some studies on paper.
Once I’m ok with the design I start modeling.
The first step is to create a very light model that I then transform into a very detailed mesh via several subdivisions: this is the sculpting phase.
I also create some separate elements that I will add later on to the model, such as a porthole for his heart, a valve for his brain (O_o) and some screws driven here and there in his body.
Once the HD model is ready, I start modeling the low-poly version (including unfolded UVs), which is the one I will texture and upload later on.
In order to texture my model, I need to bake the details and color information of the HD model on the low model.
For that I use xNormal, which can generate Normal Maps, AO, cavity maps, etc… everything I need in order to add some life to the mesh.
After some refinement and with a little patience, I finally get the following textures:
And I check the whole thing into Marmoset Toolbag:
2-Upload to Sketchfab!
Once the model and the textures are validated, I can upload everything on Sketchfab.
Before that, I need to attribute a different material to each independent part that I want to keep under control – for instance, if I want to adjust opacity for one particular part, to have a stronger specular on another part, and so on.
That’s why I identify different zones, such as the porthole glass, the character’s skin, the metal parts and finally the base.
Each element now has its assigned material and is identifiable and adjustable in the Sketchfab UI.
Now the model is ready to be exported.
I won’t detail here all subtleties of the export phase – one thing though: don’t forget to export the materials with the model, in our case in .Obj (here you can find all formats supported by Sketchfab: https://sketchfab.com/faq#formats)
Here are some scripts you can use to export from the software to Sketchfab:
Once you’ve exported your model successfully, you have to zip the .obj, .mtl and the textures (.jpg or .png) into one file which you also have to upload.
In EDIT right pane, I can adjust scene parameters:
– Model / scene name
– Model description
– Mesh rotation calibration
– Ambient Occlusion activation
– Finally, adjustment of different materials
Important: don’t forget to save your modifications!
I begin with the stone ground:
I choose the associated material, and I upload textures.
When you choose a material, the associated element is highlighted (with purple)
I upload Diffuse, Specular and Normal maps for the base.
(This window contains all textures loaded into your scene; if you don’t attribute a texture, the Color Picker color is used by default)
I adjust shininess in order to get the effect I want, plus a slight environment reflection that adds some “wetness” to the base. (Now it’s up to you to play with adjustments to get to what you want!)
Now, to the remaining parts of the model.
Here is the window glass shader:
In the Opacity channel, I upload the Alpha map (as seen above Alpha_Emissive_Maps.jpg), containing the transparency information for this part.
On a grey scale, White is opaque and Black is completely transparent.
Then I adjust Shininess and Environment Reflection to get the desired “glass” effect.
With the skin, since the Diffuse, Normal and Specular maps are the same as before I can get them in my library and attribute them to the associated channels in the skin material.
I adjust the Specular and Shininess levels of the skin to make it slightly oily.
Note that I also upload an Emissive map that renders a bright effect at the back of the heart cavity.
You can adjust this channel to your will – here I set it at the maximum which is 1.
For the metal parts I repeated the process and selected the associated maps and adjusted the Specular/Shininess/Environment and Reflection maps.
(Check the red environment reflection in the glass!)
I adjusted the specular differently for the pants in comparison to the skin, and give it a different material.
4-Fine Tuning and Publication
This is it: the home stretch!
Before publishing, you can do some general refinements:
Here, I calibrated the default position of the model.
I use an environment called “Queen Mary Chimney”, that is visible in reflections but that I’ve decided to hide in the viewport.
You can also adjust its exposition and intensity.
I’ve chosen the “clean_light” Background, which contrasts with the model. You can also import your own background.
By clicking the APN icon (top left of the viewport), you can define a default position as well as a preview.
Finally, do not forget to SAVE your modifications – and this will publish your model
I hope this will be useful for some of you. Have fun on Sketchfab! I can’t wait to see your models!
You can find all my models here: https://sketchfab.com/volumic/recent
And more of my work on http://volumic.fr/
Note form Sketchfab: Thanks JC for the blog post! If anyone has any problems, feel free to reach out to firstname.lastname@example.org
And if you feel like making a tutorial blog post for your own favorite 3D package, we’d love to publish it as well!