Raul Ramos is an Oregon-based illustrator and creature designer currently working in the gaming industry. He has a passion for all aspects of art and art making with strong interests in biology, paleontology, and comparative anatomy.. all of which have given him a great appreciation for paleo art, wildlife illustration and creature design. Below you will find one of the most thorough articles we've featured yet, which will give you an in-depth look for how to sculpt an anatomically-correct dinosaur, as well as inspire new techniques and methods for any and all creature designs. Check it out:

Research & Reference


Selecting the subject

Each dinosaur is going to be an entirely new puzzle to put together. Some will be more difficult to work on than others depending on the available data. There are many species of dinosaur that are only known from partial skeletons or sometimes just a few fossil fragments. The less material there is to work from the more difficult it may be to reconstruct the animal accurately. An extensive knowledge of closely related animals and comparative anatomy can be used to help in the reconstruction, but this makes for a considerable amount of research that can be overwhelming for those new to paleontological reconstruction.

You can see from the skeletal silhouette from the Australian Age of Dinosaurs just how little of the skeleton of Australovenator was recovered. There have been more developments with the species since this was created but when I started this is all that was known of the animal.

For those who may be attempting their first paleontological reconstruction my advice would be to pick a dinosaur that’s fairly well known. Do a bit of preliminary research into an animal you might be interested in. You should be able find a few sources that specify how much of the species has been discovered, how many specimens have been found, and if it has any close relatives that may help you fill in the gaps. Also keep in mind that many commonly known or popular dinosaurs have become so popular because there have been so many fossil discoveries of them. Dinosaurs like Tyrannosaurus rex, Triceratops, Allosaurus, and Stegosaurus, are good examples of this, and could be good candidates for your first reconstruction.

You can see in this skeletal by Scott Hartman that this T.rex is nearly complete. Making my T. rex image easier to research and complete.

Beginning your research

I usually like to start by getting a general feel for the species I’ve selected. I’ll do a quick google search and review any sources that look promising. Go over as many articles about the species as you can. See if you can find any videos about the dinosaur online. If the dinosaur has been featured in any recent documentaries try to watch them. Even websites directed toward kids can sometimes have useful facts you can make note of. While you're researching try to answer the following questions. What is the species name? How do you properly pronounce it? What does it’s name mean? When was the species found and by who? Where was it found? How much of the skeleton was discovered? How big is it? Are there multiple specimens? Are there any mounted skeletons or casts from those skeletons in any museums? Are there multiple subspecies? How is the species related to other dinosaurs? By attempting to answer these questions you will inevitably find more and more information that help you get a better picture of the animal you are bringing back to life. Follow any lead you can and take note of trends in information you’re seeing. This will help you get a feel for what information is current what the scientific community generally agrees upon.

A quick snapshot of a search and a few of the results I got for this reconstruction of Ceratosaurus. You can see that I already have articles, images and a video to take a look at. Not all of them will be a gold mine of information, some may even be way off base but it’s a start.

Eventually you will come to a point when you need very specific information that you’re just not going to find by sifting through google search results. When it becomes necessary to delve deeper into your research there are a number of different sources you will want to become familiar with to get the information you need when you need it.

Journal Articles

A journal is a collection of articles that are published on a regular basis to report current research within a given discipline, in this case paleontology. Articles in scientific journals are specific, painstakingly cited and peer-reviewed. This means that each article was closely examined by a panel of reviewers who are experts on the article's topic.

A few such journals include The Journal of Vertebrate Paleontology, Nature Communications, Plos Biology, and The Bulletin of the American Museum of Natural History. You can also access articles via journal databases like Jstor, BioOne and the AMNH Library Digital Repository. Some Journals also double as their own databases. Many Journal articles should be available online for free, allowing you to review their contents and download them as PDFs for future reference. Some journals like The Journal of Vertebrate Paleontology will require you to become a member and or pay a subscription fee to receive access to their journal in print or digital form. Others sources may require you to pay for access to individual articles. Try to dig around as much as you can for the articles that you need. Sometimes an article that requires a fee to access on one site may be free somewhere else. If you need to do extensive or frequent research paying for a subscription fee to access a journal’s issues both past and present is usually well worth it.

I became a member of the Society of Vertebrate Paleontology Over a year ago. As a member I am able to receive these printed issues of the Journal of Vertebrate Paleontology and gain access to all past issues and articles online.

An advantage to reading journal articles is that they will lead you to a number of other sources on closely related topics. Each article should have a section for references. This section is almost always at or near the end of the article. It’s used to give credit to the work of previous researchers that has been utilized in the paper. You can use this to find additional sources to continue your research.

A small part from a the literature cited section of one of the papers i’ve gone through. You can see some of the other articles I’ve highlighted that I later went on to look up and review.

As great as they are journal articles can pose a challenge to those without a background in the field. They can be hard to understand due to their use of very specific terminology to describe the various features of the fossils. Don’t be discouraged by this. Take the time to read the articles carefully. Try to digest things in small pieces. Take notes and look up any terms you are unfamiliar with. There have been many times where I’ve had to stop to redraw a diagram and label it in my own words to make sense of things. The more articles you read the better you will get at understanding their contents.

Here’s an example of a study I did while reading over a paper on Australovenator. This particular section was describing the animal's teeth I drew this diagram to better understand features the article was highlighting.

Books 

If you’re plan on reconstructing dinosaurs on a regular basis it may be a good idea to invest in some books about dinosaurs and other prehistoric animals. A couple books that I frequently reference when creating these restorations are The Dinosauria Second Edition and The Princeton field Guide to Dinosaurs 2nd Edition. The Dinosauria is a collection of articles by some of the most well respected experts in the field of paleontology. The book covers a wide range of topics including dinosaur systematics, anatomy and history. It’s full of very detailed descriptions of each major dinosaur group and has some very helpful diagrams showing skulls and bones from different angles that are useful for modeling. The Princeton Field Guide to Dinosaurs contains many skeletal drawings by world renowned dinosaur researcher and illustrator Gregory S. Paul. It depicts over 735 different dinosaur species. Like The Dinosauria many of these can be seen from multiple views.

These are some of my favorite books I’ve pulled from my library. Not all of these pertain to dinosaurs or paleo reconstruction directly but they have all contributed to my ability to sculpt and draw these animals in some way.

Images

You’ve probably already been saving images as you’ve been researching. It’s much easier to save things as you go rather than try remember where you saw that perfect piece of reference while you were reading hours or maybe even days ago. I want to call out a few different types of images you will want to keep your eye out for, and a few places to go when you're looking for them specifically.

Skeletal Drawings

Skeletal drawings are line drawings of the articulated skeleton usually viewed from the side in a running or walking pose. Often the skeleton is enclosed by a dark silhouette representing the flesh of the animal over the bones. These drawings are perhaps one of the best ways to get an idea of the animal overall. Often the artists responsible for these drawings will continually update them to reflect new discoveries or research. Scott Hartman’s Skeletal Drawings are a good source for these as he has illustrated many dinosaur species and is very open about sharing his skeletal drawings with experts and enthusiasts as reference. As mentioned before Gregory S. Paul’s book The Princeton Field Guide to Dinosaurs is absolutely full of these restorations as well.

Skeletal Drawing of Ceratosaurus dentisulcatus by Scott Hartman.

Skulls

Of course the focal point of your reconstruction is going to be the animal's head. Getting as many images and diagrams as you can of the skull from as many angles as possible is essential to creating a successful reconstruction.


Mounted skeletons

Try to find out if the dinosaur you’ve selected has a mounted skeleton on display in any museums. If the museum is near you try to visit and take photos of the skeleton in person. If not try to get as many images of the display from people who have or from the museum itself.


Scale Comparisons

An important aspect to restoring animals with sizes as varied as dinosaurs is understanding their scale. Nothing beats standing next to skeleton in a museum or a life size replica to get a sense of how truly large or small some of these dinosaurs were. But if that’s not an option for you seeking out images that show your selected species next to a human or household pet can help make decisions about your restoration. The details you place on your model should support the scale of the animal making a large animal feel appropriately large and a small animal feel small.

Ceratosaurus would be referred to by many as a mid sized theropod, but you can see from this image found on Wikipedia that compared to a human it’s still quite large.

Other Reconstructions

The dinosaur you’ve selected has most likely been reconstructed before. Knowing how other artists have restored the dinosaur can sometimes help you decide how to interpret your own findings. They can also be an important source of inspiration or provide you with something to measure the quality of your work against. In order to do something different with your reconstruction it’s a good idea to first try to understand what has already be done. Some dinosaurs have a long history of reconstruction full of twists and turns and it’s a lot of fun seeing how our understanding of the fossils have changed over time.

A reference sheet showing some reconstructions of Ceratosaurus from artists that inspire me.

Real World Reference

Reference from animals living today are an extremely important part of any successful paleo reconstructions. They are an infinite source of inspiration for poses, colors, behaviors, and countless small details that offer that all important touch of realism to a sculpture. Keep in mind that birds and crocodilians are the dinosaurs closest living relatives so it would be wise to use these as your primary references.

A reference sheet I created from photos I’ve found online. These are the scaly feet of a cassowary one of my favorite bird species.

Drawing


I usually begin by creating a 2D reconstruction of the dinosaur in a neutral pose before starting to work in 3D. This familiarizes me with my subject and allows me time to understand its proportions and anatomy. I draw the animal in a neutral pose. The neutral pose will allow me to more easily gauge distances, lengths and angles between features on the skeleton. When I model the dinosaur this pose will also ensure that I have enough resolution in areas that move and bend like the arms and the corners of the mouth. This will come in handy when posing.

I created this side view in Clip Studio Paint. I really like the pen tools look and feel for making line drawings like this.

After I get my side view done I establish some guidelines on important features and extend those out above and in front of the body. I will use these guides as well as my reference to draw a front and top view of the dinosaur. This is where a lot of images of the skeleton from multiple angles will become extremely valuable. Often times the animal’s body doesn't do what you might expect when viewed from above. With theropod dinosaurs like this, the ribcage, hips and skull are usually much narrower than many artists tend to restore them.

This is the completed orthographic drawing. From the front you can see how wide the bones of the lower leg are. Many artists tend to draw or sculpt larger theropods with ankles and metatarsal bones that are far too narrow.

3D Blockout



After my orthographic drawings are completed I can move into Zbrush and begin blocking out the model. I like to start with a simple representation of the skeleton first. I load up my orthographic drawings into ZBrush and arrange them in a grid around my model. Again I start working with the side view first. Using this view as a guide I block in the large masses of the skeleton. I use ZSpheres to create the spine and tail. The spinous processes of the vertebrae and the chevrons on the tail are represented by a thin mesh I create using a cube I extruded using ZModeler. I use shadow box to generate the mass representing the rib cage and the general shape of the skull. It's important to understand that I’m not trying to make a highly detailed sculpture of the skeleton. That would be a challenge in and of itself. What I want is a simplified version of it that I can use to overlay muscle and skin on top of.

Here you can see my initial blockout of the spine ribcage and skull. I want to keep things simple and blocky so I can make progress more quickly.

I do a bit of refining of the ribcage at this point. Using the move brush to make large adjustments to the overall shape. I use clip curve to remove large sections of clay. Any planes or hard edges are rounded out with the trim dynamic and smooth brushes. The Last thing I do is give a minor indication of where the ribs are located.



The legs arms and skull get much more attention than the rest of the skeleton. I need to be more specific with the structure of the limbs and skull so I can place the musculature more accurately. This is the most time consuming part of the block out. I’m constantly checking my reference and overlaying my sculpt on the images I’ve found to make sure they are looking correct. This is where a lot of patience is going to come in handy. These areas contain some very complex structures and numerous small bones. Try to break things up into small pieces and work your way through the skeleton a step at a time.

Here you can see the skeleton with the limbs added on.

Labeling the elements of the skeleton after it’s completed helps me internalize the information I’ve learn. I can also use this for future reference.

With the skeleton completed I can begin to add the muscles in. I modify the curve tube brush by enabling lock start, lock end and size in the stroke menu. I also adjust the curve falloff so that the curve slopes down for upper left to lower right. I add a point in the middle and pull it up to create a hill shape in the curve. This will give the curve stroke a wide starting point that tapers toward the end with a gentle bulge near the center. This will mimic the basic form of a muscle. I’m going to use this to begin blocking in my basic muscle groups over the skeleton.

Here you can see my curve settings in the stroke menu.

I drag out a curve on the skeleton using reference to guide me on the placement of the muscles. I’ve collected several journal articles that focus specifically on dinosaur muscle insertion and attachment points. I’m also using reference of crocodilian and bird anatomy. After the curve is drawn out I can change the placement of the start and end points to match the origin and insertion of the muscle. Enabling lock start and lock end in the stroke palette ensures that these points won't move once I’ve placed them in the correct spot. This allows me to focus on the curve and make sure the muscle is running across the skeleton correctly. Once I’m happy with the curve I clear it leaving the mesh behind. I can then make further adjustments to the form using the sculpting tools. This process is repeated for each muscle.

This is the transversospinalis capitis muscle I’m beginning to insert on the neck.

As with the skeleton a lot of patience is required here. It’s easy to become overwhelmed or confused by the number and placement of the muscles on the skeleton. I recommend working on the muscles in sections, head, neck, arms, legs, tail and torso are usually good manageable areas to tackle in a sitting.


Refining


Once I’m satisfied with the muscles I merge all of my subtools together and dynamesh them into a single mesh. After dynameshing there’s usually some cleanup that needs to be done. Any holes resulting from gaps in between the muscles and spaces in the skeleton need to be filled. Seams or separations between muscles and attachment sites on the skeleton need to be smoothed. Do a thorough pass over the whole mesh to catch any spots that need adjustments.

Here you can see the model before and after I’ve merged the muscles and skeleton together. I’ve smoothed out a bit ot the transitions between each element

After I’ve merged everything and patched up the mesh I can begin to refine the model. Some of the forms have lost their detail from the merging process. Part of refining is adding definition back to these areas. I use the clay buildup brush at a low intensity for most of this portion of the process occasionally using my crease brush or standard brush to re-emphasize anatomical details. What’s really important to me at this point is that I achieve the look and feel of muscles under skin. Much of this has already been done for me using this ecorche approach to construct the model. Nevertheless certain areas may require a bit of exaggeration and others may need to be toned down. I work through the whole model in this first pass before moving on.





This is the model as it appears after some refinements have been made

The last stage of the refinement pass is incorporating some of the larger wrinkles and folds on the body. It’s really easy to get caught up in micro details at this stage. Try to stay focused on the larger more noticeable forms. There will be time to focus on small wrinkles and other skin variations later. There tends to be a lot of experimentation to get these wrinkles working correctly. If you want to avoid some unnecessary resculpting of the surface you spent so long refining, I suggest storing a morph target or working on a layer. This way you can erase or delete these details without impacting the underlying sculpt.

Wrinkles were added using a variation of the standard brush with gravity enabled in the draw palette. This adds a sense of weight to the wrinkles as they will start to sag the more you sculpt over them.

Retopology


Before I begin to detail I need to make sure my mesh is prepared properly. Up to this point my dynamesh model has done the job, but there are some limitations to it. If I continue to use it and subdivide the model to get more detail it won't be long before I reach the limits of the number of polygons my computer can handle. Also dynamesh isn't concerned with generating topology that flows with the features on my mesh. What I want is a mesh that has a topology flow that follows the creases and contours of my model. This will help me preserve detail and reduce the number of polygons needed to retain those details.

With my model in frame mode you can see how dense the mesh is. Take note of how the mesh disregards the flow of the details I’ve sculpted into it.

I make a duplicate of my dynamesh model to reproject from later and proceed to draw out a few guides with the ZRemesher guides brush. I make sure I place loops around the eyes and nostrils and follow any major wrinkles or creases I want it to maintain.

Zremesher will try to follow the guides you place on your model. I try to put as few guides as possible on the surface. I’ve found that zremesher’s results are more reliable this way.

There may be a bit of trial and error here to get the result you want. Experiment with the number and placement of guides until you find what you’re looking for. Sometimes, if you’re lucky, you won't need to place guides at all.

Here you can see the how the density and flow of the mesh has changed. Notice how the polygons now correspond to the flow of the wrinkles in the area of the torso.

The new ZRemesher model has better topology flow but lacks detail. To get my detail back I will need to project the detail from my old dynamesh model I saved as a duplicate earlier. With both models visible I divide the model once and project and check for any problems in the mesh. Sometimes in tight areas like between toes and figures the mesh will become tangled and will need to be smoothed. I will repeat this process of subdividing and projecting until I’ve reached my desired subdivision level. You can test your mesh by sculpting on it to see if it has enough resolution to accept the detail you want to put on it.

If all goes according to plan you should not be able to tell the difference between the two meshes after reprojecting.

Detailing


I start the detailing phase by creating a new layer. On this layer I start to lay in wrinkles using a custom brush. The brush is very similar to one used by one of my favorite paleo artists David Krentz. It’s basically a standard brush with the roll feature turned on in the stroke palette and alpha 58 set as the active alpha. I’ve modified this alpha slightly by blurring it and straightening the lines a bit but the default alpha works fine. I want to do a full pass of these wrinkles over the whole body paying special attention to the areas that see a lot of movement.


Next I create a new layer for the scales. Dinosaur scales are very distinct so it’s difficult to make an alpha created from a living reptile look convincing. Try to find out if the species you are working with was preserved with any skin impressions. If not try to see if a close relative has. This will help you make decision about the types of textures you may need to create to get the right effect. I use a custom alpha I created to apply the first pass of scales over the model. This will become the foundation that I build more complex scale patterns above. I use the displace brush with a drag rect stroke at a low intensity to apply my alpha. I prefer hexagonal shaped alphas over round ones because they allow me to fit the alpha strokes I make closer together with less overlap and empty spaces between. This minimizes the amount of cleanup I will have to do later.

The alpha I used was created in Photoshop. I have several variations of it and I continue to modify and improve it to suit my needs.

There are a lot of advantages to using alphas to add detail to your model, but I would not recommend using only alpha textures. The surface detail can become monotonous and uninteresting, and the more you use the alpha the more obvious the repetition will become. For this reason I always combine hand sculpted detail along with the alpha’s I use. You can see this most easily on the more ornamental scales I created along the dinosaurs back. I use a combination of masking, inflate and several sculpting brushes to achieve more complex scale patterns.

Here you can see the process I use for creating more distinct scales on the body of the dinosaur.

I continue to work through the model applying alphas, re-emphasizing areas after their application and adding in hand sculpted details over top. Each subtool is given a detail pass until I’ve achieved the level of detail I want.

Here is the final version of the model after all detail passes have been completed

Color


I love learning about and experimenting with color and pattern and this interest definitely comes through in my choices for skin coloration in my reconstructions. My dinosaurs tend to have areas of bright color and bold patterns. However I do want to make sure that my colors don't become too garish and maintain an element of believability. I usually start brainstorming by going through my references for inspiration. If nothing strikes me as interesting I might do a secondary pass of reference gathering specifically targeting color. After I’ve found a few references to base my color choices and patterns on I begin to create a few color concepts in Photoshop.

I was really inspired by Savannah monitor lizards for the colors and patterns on the Ceratosaurus.

Once I feel like I have a few strong ideas I move into Zbrush and begin to the painting process using my concepts as reference. Before I start polypainting I make sure that I bake all of my detail sculpting layers down. I also want to fill each subtool with white and and the SkinShade4 material. This will give me a good base to start painting on.


I usually stick to using the standard brush for the majority of the painting switching between different strokes and alphas to get different effects. I have several custom painting alphas I use during this stage to create a sense of randomness and add more naturalistic breakups of color. Many of these alphas are simply copies of some of my favorite spatter brushes in Photoshop.


The SkinShade4 material is a fairly low contrast meaning that your details may not show up quite as well as they might with a different material. To combat this I will add darker colors in cavities and crevices to re-establish some of that contrast and pull out the detail I want. You can also mask by cavity to isolate the low points of your model. Invert the mask and paint the low points with a darker color.


I keep fine tuning the texture, adding contrast, color variation and details until I’m happy with the overall look. The final painted model ended up being a combination of concepts B and C from my color comp sheet.
This is a quick BPR render of the final painted model. This can help to get a sense of how the model will look in a final render and highlight any adjustments that may be needed.

Posing


Before posing the model I like to do a few sketches exploring some different poses. This saves me a lot of time and effort when I begin to work in 3D. It’s a really terrible feeling to start posing a model only to find out the the pose isn't what you wanted and then have to restart from the beginning. You can really waste a lot of time this way.

I used Clip Studio Paint to make a sheet of sketches exploring various poses. These are quick sketches 5 to 10 minutes each.

Once I have a sketch that I like I’ll begin creating a ZSphere rig for my Ceratosaurus. I’ll use this rig in combination with Transpose Master to pose the model. This is my prefered method of posing characters and creatures as it does not distort the mesh very much, you can pose multiple subtools at once and the ZSphere armatures are easy to construct.

The ZSphere armature bears a strong resemblance to the skeleton. This will help me pose the model much more naturalistically.

Once the ZSphere armature is done I copy it using the Transpose Master. I’ll then make sure ZSphere Rig is enabled and click on TPose Mesh. This will take all of my visible subtools, set them to their lowest subdivision level and merge them into a single subtool. A ZSphere will appear at the center of the transparent mesh. I need to replace this ZSphere with my ZSphere armature by clicking paste TM Rig in transpose master. Before I start posing I need to test the amature. Selecting bind mesh in the rigging sub palette will tie my ZSphere armature to my model. I can then move the ZSphere armature to pose. I’ll move the armature around a bit to see if everything is working properly. If not I’ll make adjustments by adding, deleting or moving ZSpheres in the armature. When I’ve worked out all the kinks I can start to pose using my sketch as reference.

Things are always going to change when you begin to recreate the pose in 3D don't get too caught up in trying to match your sketch exactly.

Once I’ve satisfied with the pose I’ll click TPose|Sub T making sure layer is also enabled. This will apply the pose to my high-resolution subtools and make a new layer for the pose. I will be able to turn the layer on and off to return to my neutral pose if I need to. There may be some cleanup to do on the model to fix any unwanted distortion.


Rendering


With the pose finished I settle on a camera angle that I feel shows off the model and the pose the best. Once I start rendering I don't want the camera angle to move. The compositing I will be doing will require each render to line up perfectly. I save my view in the ZApplink Properties subpalette under the Document palette to make sure I can reset my view even if I accidentally shift the model.

Turns out I was pretty attached to the camera angle in my thumbnail. I adjust it slightly and make sure it’s saved with ZApplink.

I’ll be rendering out a series of images that I will be compositing with Photoshop. My first priority is adjusting the render settings. In the render palette under BPR Shadow I change the value of the angle to 30 and number of rays to 20. This will give me slightly softer shadows over the model. Keep in mind the higher these values are the longer it will take to complete each render. With my settings adjusted I start rendering out several different light sources by changing the angle of the light in the light palette.

For the sake of convenience I’ve docked the Light and Render palettes on the left and right of the viewport. You can also access these palettes in the palette menu above the viewport.

Each light source I render will come from a different direction. Front, Top, Bottom, Left, Right etc. I want to cover all of my angles so that I can customize the lighting in my layer stack in Photoshop. Organization is going to be key here. I need to make sure I’m naming each render pass correctly to avoid confusion and save myself a bit of time.

These are all of my render passes for each of the main light sources I will be compositing together in Photoshop.

All of the render passes I’ve saved out from Zbrush are combined into a single document. With the neutral light source as a base I begin to add the other lights on top. This can be done a couple different ways. The layers can simply be reduced in opacity to emphasize one light source over another or they can be added together using screen. This phase requires a lot of experimentation. Play with the opacity and blending modes of each light source until you achieve the lighting scenario you want. You don't have to use every light you’ve rendered out but doing so can achieve a global illumination feel that can be very appealing.

Here you can see the Zbrush renders being comped together in Photoshop. I’ve enlarged my layer palette so you can see how each light is being added to the neutrally lit model.

Additional lights such as back lights are rendered to pop the model out from the background. I also render out a few images of the model using a different material like the ReflectedMap or ToyPlastic to add specularity to areas like the mouth and catch highlights on the scales. These are added to the Photoshop document and the opacity or blending modes are adjusted to fit the render into the scene.

Here you can see the render with the backlights and specular material added. Again I’ve enlarged my layer palette so you can see how I’ve added each additional layer.

Final touches can include using photo textures to give a bit of grit to the image Filters such as lens blur are great to add depth to the image and pull focus to important areas. Noise can also be added to add a bit more break up to the surface and a touch of realism. Other details can be painted in. Subtlety in these finishings stages is essential. It is really easy to go overboard with these effects.

Ceratosaurus dentisulcatus final composited image.

We'd like to thank Raul for providing us with such an epic breakdown of his technique. Don't forget to check out his website to stay updated on his work!