Modeling

Subdivision Modifiers

When modeling objects in Blender keep in mind that objects do not need to be highly detailed geometry in order for it to render as such. In other words, depending on the object it is far easier for both the artist and Aqsis to keep it as simple as possible. Walls, floors and ceilings do not need to be more than a few polygons if they do not have to, though it may require a SubD modifier applied to them in order to prevent what is known as "grid cracking". The objects that require a fine edge while still remaining smooth will need some editing in Blender to crease right. Using best judgment on poly count is essential when applying SubD modifiers to objects, if one were to visualize what Aqsis "sees" when it renders a SubD sphere you could turn up the Level to 4 and that would look similar for instance. While in the literal sense this is NOT how Aqsis dices up geometry, that is something for modelers to remember : more polygons does not mean better. In many cases more polygons means that Aqsis has to work harder at something it doesn't need to.

Quad geometry is ideal for this as it is much easier for Aqsis to dice up, rather than triangle geometry. Sometimes it is not possible to do so, in which case make the best of it. In those cases using Aqsis to preview the mesh should be important, as opposed to the Blender Internal renderer which is designed to handle the geometry generated in Blender (obviously).

Aqsis can handle any geometry thrown at it, even things not FULLY exportable from Blender (such as NURBS surfaces which in that case it exports unpredictably and not accurate at all).

Preview using Aqsis

It might be a good idea to use Aqsis to make periodical preview renders in case there is something wrong with the geometry, sometimes it is possible that faces are not built right for Aqsis to dice up (or most RenderMan software). Sometimes this can result in cracking, which looks very bad in the final renders and can be a huge pain to fix later on. Though in case it does happen and it might happen when you least expect it, make note of it and we will try to correct the geometry issue in Blender. Sometimes it won't show up until later, or at a camera angle different than what you were using for modeling. Try to do preview renders at ALL angles to avoid such complications later in the process.

Materials

When modeling an object make sure that Blender materials are assigned to geometry that has a different look than other parts of the geometry, such as if there is half one type of Material that is to be a metal look to it and another Material that has a dirt look to it. This will save a LOT of time later on when doing the shader and texture process, especially with complex geometry. It is not required to make separate objects in Blender for each type of Material, though if you do decide to do so make sure it is Parented so when moving them around these objects remain in place. The reason for a Material assignment is so that later on there is not a complication when changing custom shaders or textures, it just makes the rest of the process smoother to complete.

screenshot_052209_001.jpg

(note : below is very incomplete note)

Export + Render Time Optimization

We are going to have to reduce export and render times as much as possible. Some of the normal ways of building scenes in Blender will cause some serious issues when it is exported to RIB format and then rendered, having multiple objects of the same type is not only going to increase the export time (as Mosaic exports each object) but it will also increase disk space.

  • Instancing (Alt+D)
  • DelayedReadArchive (RenderMan RIB asset rendering method)

Instancing and DupliVert methods are a good way to duplicate objects within Blender without actually increasing export times, per object. These ways only export a single RIB mesh file, the RIB Scene file then calls on that RIB mesh file multiple times, this way only one RIB per instanced object is created, thus cutting down export times substantially.

DelayedReadArchive is a RenderMan method to only call upon an external RIB file (such as an object) on the fly, that is if during rendering Aqsis does not load that RIB data into memory until it absolutely has to. This will reduce render times simply because the memory isn't tied up with unused data.

There is also other ways to reduce render times.

  • Shots that only need x amount of objects will export faster
  • Compositing can reduce the amount of frames NEEDED (still backgrounds only need 1 render)

Other misc tips and tricks can be found here as well.

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