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Persona Non Grata
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I was thinking of asking this same question.
Let's say I make a barrel of beer model and I want to be able to import it into Carrara, or Poser, but I don't want the polygon count to be larger than is adequate. Too few polygons would be trouble too. Is there some kind of adequate "polygon size chart" than someone has posted out there in Webland, for various objects?
Sorry Selina for barging into your post but I would like to know the answers and suggestions for this too.
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Gary Miller mentions good polygon limit size counts in some of his Hexagon videos, but I didn't take any notes while watching them. Time to watch some of them again. It's like being in school again, but fun this time.
I think you are asking a good question.
In general, the lowest polygon count that will satisfy the rendering needs is best. When the camera is very close to the object you will need more polygons of course. Because LOD (level of detail) support is not consistent across rendering applications, you probably will need to create multiple resolution objects, for close renders and a lower one for further away, especially when you have LOTS of objects, like using replicators.
I don't use DAZ Studio myself, although I seem to recall there was some plugin that would do LOD from a single object with higher resolution... it may even be built in now?
Carrara has a plugin that will let you replace objects in a scene with another object, so you could have a lower resolution object for scene creation, or when using a bazillion repicated objects that will be seen from a distance. For a close in shot at render time you could swap out the low resolution version(s) for the higher ones.
Hard to pin a specific # of polys on any object as a limit though.
The resolution of the cup and saucer meshes look fine for that close of a camera shot. Farther away camera shots don't really need meshes at that resolution. For those kinds of models, the proportions of the meshes come into play more when you are UV mapping and painting/texturing the models.
Anyway, 5,000 polys is a good enough number for such objects. 50,000 polys is normal for organic models like dogs/cats. 150,000 for humans/aliens. I rarely hit the smooth button more than twice in Hexagon for my models. Video game content uses a 1/25 of the polys for its models, since normal maps replace most polys.
Personally what I look at is the shape of the object, if you look at the cup - the rounder you make it the better (so it does not give you sharp edges). The lines going across the object does not need so many, you'll need edges for the handle, and a few to keep the shape (helps with mapping as-well - stops texures looking stretched). Select an edge, Loop it then press the back space key.
The chamfer option does come in handy.
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Curved edges on objects can be controlled using just three edges, depending on how close they are spaced together before smoothing.
true inside Hexagon
when I export a mesh to Carrara it's still fine but dare to export subdivision surfaces to OBJ I can easily get millions of polygons (shock)
Huh? You already have millions of polys when smoothing, no matter what the app.
What is the shock there? Subdivision creates more geometry that is kept in a "potential" state within the program. The .obj format can't handle cage geometry with a flag "subdivide this", so for export it has to be turned into "real" geometry.
Hi @Selina, I would recommend trying to not use subdivisions for non-organic objects (and even organic objects if they do not bend). Make use of the surface attribute called smoothing angle in combination with edge bevels and use enough geometry so that visible profiles are not blocky (based on how close the camera will get to the object). FYI....The robot that I just modeled in Hexagon, has 64,000 polygons. There are some areas that I wished I had used a few more (but live and learn).
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The renderer can only do so much. Your model has normals for facets, and normals for edges. They all have to be set right. Otherwise, strange shaded corners on your model.
Hi @Selina, your right, I am referring to the smoothing parameter for the surface property for the renderer. Just a way to cheat so you do not have to dynamically subdivide everything (which quadruples your poly count for every subdivision level). I have attached a pdf showing an example (my cup design is not as nice as yours). Not perfect but hopefully it gets the point across.
Also.....thanks for the comment about the Robot. I was checking out the new Lost in Space on netflix which got me thinking about how I much I enjoyed the original Dr Smith and Robot which got me modeling good old B9. I have him rigged and surfaced now I need to animate him (including the lights). I hope you check it out when I am done.
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Hexagon does not have crease edges, if I recall. In order to get a hard edge, the mesh has to be split (disassociate) along the edge that needs to be hard.
Shawn's method above is useful if you dont need an extremely sharp edge. It can create a nice "soft" edge beween surfaces.
Incorrect. It is available in the Smoothing Tool
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@Selina, because I export my obj with a smoothing value of 0, my robot has 64,000 polygons. If I export with a smoothing value of 1, my robot would have 256.000 polygons. That would make the model much harder to UV map and rig and animate and use. Usually your renderer application will allow you to subdivide your model during rendering. That allows you to keep the model as lower poly while not rendering. Not sure how Carrara handles that since I use Daz.
Smoothing Angle is not a value you set in Hexagon. It is set on your material in your renderering application. The smoothing angle value does not increase poly count like subdividing does. It takes the normals into account and renders a smooth edge across 2 edges based on their angle. I provided an example in the pdf document.
Your picture is a demonstration of subdividing which quadruples your poly count for every smoothing level.
Here is my 1250 polygon cup rendered using the "render only" SubD level setting that I mentioned above. Hope it helps.
When you export the file, are the edges still sharp? Doesn't the smoothing control subdivision only, not normals?
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Good, you found it. Vertex Normal is what it is called. By the way, I do all my edge creases in Carrara after exporting as OBJ from Hexagon. I haven't found a modeling app that does it as well as Carrara does. A lot of apps want to just smooth the entire model and make edges on them by moving edge loops closer together, or by using vertex weight maps.
Most of my modeling is lo-res that just needs basic creased edges applied.
OBJ exporting will collapse the geometry, so it looks like this in Carrara with bad smoothing normals (which confuses the Phong shading). So creasing the edges in Carrara fixes things. Maybe the latest Carrara is not allergic to this?
The other way is to bunch edges together, and then smooth. But this is mostly for smooth organical modeling. Nothing that's hard-edged mechanical modeling.
I have, which is why I made the comment, see Shawn's comment with a picture of what happens in Carrara, which is why crease edges can only be applied in Carrara. I think some of the confusion lies in a double meaning for smoothing. Smoothing can refer to subd's or normals.
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