Step 1: Collect references
Starting with a new project, its always pays off to do some research first. Do a Google image search, maybe look at scientific information or on a Wiki page. Look it up in an Encyclopedia. Anything that can help you get a rough understanding on what the object is, its purpose and function.With a pre-historic creature like our Dimetrodon, it wasn’t hard to find some images. Of course most of the artistic imagery is mostly derived from the imagination of the artist since no one really knows how these animals really looked like. But this is also a big plus. It gives you a certain degree of creative freedom. I looked at a lot of references for reptiles as well (although the Dimetrodon actually wasn’t a reptile but an ancestor of today’s mammals). This gave me a good impression of how beautiful and colorful nature actually is. The “dinosaurs” don’t have to be brown. 🙂If possible, you might also look for references of the object in side, front or top view. These can help you in the process. Most software packages allow to import background or reference images, so you can always check your proportions while sculpting.
Step 2: Sculpting
For the sculpting part I decided to use 3D Coat as a learning exercise to get better acquainted with the software. But you can also use Blender’s fantastic sculpting tools.The main principle in sculpting is: Start with rough forms first. Get your proportions more or less right, then get into finer details. Don’t get discouraged because the sculpt doesn’t look good, and resist the temptation to rush into introducing detailed work on some parts of the model. As someone said in a Youtube tutorial: “Your sculpt will look hideous for a long time until it suddenly doesn’t”. 😉Normally I would paint the fine skin details as a bump map, but in this case I decided to sculpt them all in, and then use the high resolution sculpt to bake that information onto my low resolution retopologized model.
Step 3: Retopo
Is there anyone working in 3D who actually enjoys retopology? 😉 For me, this is a highly tedious and often frustrating stage in the process. But there is no way around it. For static meshes I would use an automatic retopology feature, like the Autopo function in 3D Coat, or Instant Mesher. But for a model that needs to be rigged and animated, it is unavoidable to manually create a low resolution version of the sculpt (Could someone PLEASE develop a smart tool that does that automatically for humanoids and quadrupeds?) Then you can unwrap it and get clean UVs for texturing.
Step 4: Texturing
Texturing an organic model can be done in different ways. If you have good texture images you could just paint them onto your model (stencil mode). In this case, I decided to do all the texturing from scratch in Substance Painter.Substance Painter is absolutely fantastic for using information from your highpoly sculpt to generate a curvature, ambient occlusion and normal maps. These maps are then used to create texture layers based on smart masks (for effects such as edge wear, or in this case the details of the creature’s skin).
Step 5: Rigging
Rigging was quickly done in Blender, using the Rigify option. I used the “wolf” preset and then had to tweak the metarig a bit, especially for the head and tail. And I had to add some additional bones for the feet and the sail on its back. When you do this, make sure you don’t just add bones as you would normally do, but instead use the “add sample” feature in the armature tab (see https://www.youtube.com/watch?v=_I83_zDxoxw). Then just hit “Generate Rig” and voilà, you are done!I usually test the rig and the weights by twerking and bending the whole thing to its extremes. If some portions of the mesh have strange deformations, you can adjust the weights in the weight painting mode. If everything fails and you still get unwanted behavior of the mesh, you can use shape keys.I run into the problem that the neck was folding to heavily with certain head positions, so I tried to fix that. It wasn’t perfect, but the kind of extreme head positions is probably unnatural anyway, so I decided to leave it as it is.
Step 6: Animation and presentation
After all the hard work is done, it is tempting to just quickly render an image and finally present your beautiful model to the world. However, it really pays off to invest some more time an energy to present your model in the best light possible.I imagined the Dimetrodon in a forest-like environment, created a pose and a quick short animation. For the environment I used an HDRI from hdri-haven.com and some assets from the megascans library.Bam! All is done. You have a game-ready asset that you can animate and export to your game engine.If you have any questions on the process or run into some technical problems, just ask. I can send you an invitation to a discord server that is dedicated to Blender and Unreal Engine. Or just drop us an email.