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Isleofgough

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About Isleofgough

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    C4D Cafe Junior
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  • First Name
    Philo
  • Last Name
    Calhoun
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    Seattle
  • Website URL
    www.ohsu.edu

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    R20 Studio

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    16 core

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  1. Thanks again. I discovered several things in this project: Box modeling in general gives much better anatomic edge loops than edge extrusions/retopo. Add and remove edge loops as needed rather than apply SDS. Don't do any complicated parts early, as they are a pain to edit later (fingernails). My criteria for a good model was: 1. all quads. 2. only 3 and 5 edge spiders and even these should be placed where minimal bending occurs. 3. For rigging and UV purposes, one should have an edge loop that splits the model in palmer and dorsal sides. 4. For rigging fine tuning (vertex weighting), your model should be able to be decimated so that parts can be parented to bones and the motion should look good. (this follows Tina O-Hailey's recommendation for rigging in Maya and the Houdini hand rigging tutorial series). See attachment for rigging by parenting and final result.
  2. Here is a shrink-wrapped hexagon grid, and you can adjust the points as desired. Note, this is non mathematical, as you cannot have a sphere composed of all hexagons. But 3D is basically an illusion anyway. I can't give the specifics for how to do this in C4D, as I no longer use the program, but I know there is a shrink wrap deformer. Another way to consider is to use booleans and the volume builder. It will not create pretty topology, but that may not matter. Here, for instance, is a woven chain run through the equivalent of C4D's volume builder. (Modeling is easier in Houdini for this sort of thing, as you can make anything that you can conceptualize). BTW, your client must not know what bacteria look like, because they are nothing like the example. These are closer: https://www.turbosquid.com/3d-models/3d-bacteria-pack-1304068
  3. Your image was done in Rhino, a nurbs modeler, but I don't know the details. (https://www.grasshopper3d.com/photo/triple-weave-sphere-print?context=album&albumId=2985220%3AAlbum%3A1013783) One tipoff is that this is two spheres covered with hexagons having every other point scaled towards the center. At that point, you are correct, it would be an atom array with subdivision. I think this was done with soft selection transforms, rather than mathematically, as covering a sphere with hexagons will actually require a few pentagons. They can be hidden in the back, or you can shrink wrap a hexagon grid onto a hemisphere and the render will hide the issues. You can see the thickness in the woven areas actually varies considerably in thickness in your model and some of the hexagons are pentagons in your illustration (two loops instead of one are woven). Something like this:
  4. Open a single png in photoshop and see if it has transparency. If it does not, it will not work in AE.
  5. Cerbera has rightly reviewed the options. Quad remember was done by the same person as Zbrush's algorithm, so they will likely give the same result. Another option to consider is purchasing Moi3d. It often has the best method for covering CAD models to polygon surface objects. I think you can get a trial of that program.
  6. I generally avoid bevels except at the end of modeling, except for very specific cases. In other programs (Modo, Houdini), there is a rounded edge shader that can soften some of the sharp edges, and then you may not need bevels at all. If you are willing to have extra edge loops, you will probably get a softer result. Here are a couple of bevels in another program, but you can adjust settings in C4D's bevel tool to give either result (as it is as good a bevel as in any program).
  7. I should add, here is a typical example of retopology edge loop issues with edge extrudes (not my model). Only one edge loop is selected. Also attached is a test of very unequal sized polygons with a checkerboard texture applied to the diffuse and displacement channel. I'm not seeing distortion. It would seem that the only way distortion would occur is if one changed the UV map after the high polygon model was converted to a displacement map in Zbrush and that even size of the polygons doesn't have much bearing in displacement.
  8. Retopologizing with the TopoPen or equivalent causes some shrinking after SDS is applied The shrinkage with the TopoPen is straight math from the Pythagorean theorem. The larger the polygons created, the more the subsequent SDS will shrink away from the original high poly model. When SDS is applied, basically the mid position of each polygon remains the same but the edges and vertices will be rounded away from the points. The TopoPen snaps vertices to the surface. To avoid shrinkage, the face itself would have to snap to the surface, which it doesn't (nor does Modo or Blender or Houdini's equivalent). The shrinkage can be seen by just adding SDS to a cube. (See attachment below for shrinkage regardless of how high poly the original model is). The original corners move inward to be more spherical. Placing smaller polygons might help, but it is really easy to inadvertently create spiral topology or differences in the number of polys between fingers. Regarding the fingernails: sculpt or model I wasn't suggesting having the fingernails be a separate object from the hand. See attachment below for potential issues with modeling the fingernail and then trying to superimpose a displacement map on top of that. It is important that the polygon edges exactly line up with the fingernail edges, as I would add different reflectivity and roughness to the fingernails compared to the skin of the hand. RE non planar polygons That is an argument made in the Modo forums for isoline editing. See attachment below for a Luxology created hand model with and without open SDS applied. You can see the points very jagged and non planar polygons. The argument made is that since SDS will be applied, it doesn't really matter if the points are jagged in the non SDS model. But that might be an issue if one wants to do any auto weighting of the points to a rig. That model is interesting, as it has several points connected to five edges even in areas where motion of the skin will occur. (What Mr. Vaughan calls "spiders"). It also would be a bear to map skin to bones, as it does not follow anatomic topology. The polygons do vary considerably between the palm of the hand, where they are basically square, and the forearm, where they are enlongated. Does the displacement map cause a problem if one doesn't stretch these with the UV map? If one created a grid with very dense mesh one one side and few polys on the other and then added a planar map, wouldn't a checkerboard displacement still work well? The issue of SDS weighting is basically editing with isolines. See discussion above. Thanks for the answers. I'm still a bit confused on the best way to proceed. I did add a small amount of polyextrude to the high definition mesh to prevent shrinking with subsequent SDS of the retopologized model, and that seems to have worked. Obviously, smaller polygons hug the high definition mesh closer than larger polygons, so I see the value of uniformity of polygon size in this issue. However, I'm not sure the additional five edged points and non anatomic loops wouldn't be a greater problem.
  9. I would like to get some advice for retopologizing a sculpted hand model. Specifically, I want to be able to texture/UVmap the model, add displacement and rig with a fairly detailed rig that allows even a few degrees of metacarpal flexion for an animation. There are several factors generally recommended for topology: all quads, minimally non planar polygons, even size and distribution of roughly square polygons, avoiding more than five edges per vertex/point and even for five edges, to put in areas that don't move much.. But especially important are following anatomic relationships and the ability to move the displacement of a Zbrush sculpt onto a lower poly model (which can cause some problems with using inner and regular extrudes/bevels for fingernails and knuckles. Retopologizing with the TopoPen or equivalent causes some shrinking after SDS is applied and can give more non planar polygons. Modeling with isoline editing gives a good look, but might be a problem with weight maps, as the vertices in the non SDS model can be pretty jagged. (see Modo example) Attached are some models I've looked at for inspiration: several of the highest rated from Turbosquid, the asset that comes with Modo, and various tutorials on the internet for box modeling or edge extrusions or sculpting. I did a basic box model in Houdini and then used its equivalent of a shrink wrap deformer (ray node) to get close. For a project like this, would you model or sculpt the fingernails? Do you recommend downsampling or extrusions or avoiding points with five edges on moving parts? Is having higher detail in the fingers that are animated and lower on the back and palm of the hand an issue, as the polygon size will vary a lot. Here is what I have come up with and the references I've looked at. The Turbosquid models are on the right. Thanks.
  10. I know this is not about C4D, but if you look at the daily challenges done in Houdini, it is a lot of fun. They just started this in July: hourly daily challenge- https://www.sidefx.com/forum/
  11. Blender has a lot of things hidden (and a lot that work one way if done in the viewport and another if done in the outliner). Some things (like instancing on verts) are just plain buggy. I would agree with you that C4D is much easier to learn than Blender. Personally, I think Blender is overhyped since it is free. If you want a decent alternative to C4D for modeling (non procedural), Modo would be much better to learn than Blender. Modo is not very popular except in certain niches, but it is the best modeling program on a Mac and tied with 3ds max for that honor on a PC.
  12. Depending on whether you want to see this logo from another angle, you could simply do this with the polypen. Here is an approximation of the upper part with the Houdini equivalent of Polypen (which is a bit worse than C4D). Add a few edge loops and subdivide to create final form. As CBR indicated, the tip should be simplified/reduced to "kite polygons". There are a couple different ways of seeing the shape, and I'm not sure which way you want to go.
  13. Each 3D program requires a slightly different way of approaching a topology problem, but generally one can get to the same place with about the same number of steps. In Houdini, for instance, the first example would be done with a single polyextrude (inner). The second requires a single bevel (polybevel). The third requires two nodes: a poly split and a triangulate. The fourth is done easily with creating a construction plane. Blender has similar options, but probably one would not do this all with the bevel tool. You don't need some fancy plugin to do this sort of thing. In my experience with XSI, Modo, Maya, Blender, and Houdini - the bevel tool can be quite different between programs. In Modo, the bevel tool is often used for an inner extrude. The bevel tool in C4D used to be pretty poor, but the current version makes it a bit more useful than the bevel tool in some other 3D programs. I don't think you can extrapolate that to say that C4D is overall better or worse as a modeling program than other 3D programs. If you are comfortable using the bevel tool alone for this sort of work, C4D might be your best option. I would be a little careful about the example of sliding you used with C4D. It can create bad topology if you are using it with a non planar structure. In general, the bevel tool is the most apt to create triangles and ngons if not used carefully, compared with extrusions and edge loop cuts. Just to show, a simple inner extrude works fine if the structure has three dimensionality. See attachment.
  14. Since standard rendering engine does not follow real physical properties, it can be hard to tweak. I think that was one of the reasons people migrated to engines like VRay before physical rendering was developed. Even non physical materials can be an issue. I hear Arnold is good. Good luck.
  15. I don't have C4D to check, but when I had it, I only used standard render engine for NPR (Sketch and Toon). Have you tried physical render?
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