Follow the guidelines described here for best interoperability between AutoCAD and Showcase.

Layer assignments

With Showcase, you have the ability to select multiple objects based on the selection of one object; that is, based either on the same material or layer as that selection. So when you assign layers in AutoCAD, try to create them based on material assignment (which also helps speed things up in AutoCAD), or by grouping objects that may need to be selected together in Showcase. Grouping by material can also be useful when exporting to 3ds Max. Use AutoCAD blocks to group items; AutoCAD groups are not supported by Showcase.

Model location

If you do not need to have the AutoCAD model geolocated, try to place the model at the origin (XYZ=0,0,0). This avoids potential issues when adding an environment in Showcase.

Units

Sometimes AutoCAD may not be using the units you expect. Check File Units in AutoCAD (_UNITS), and make sure they are consistent with what you are doing. This is also useful when working with materials, since they retrieve the unit exposed there. For example, you may think that 1 is 1 meter, but for it may actually be 1 inch. When importing to Showcase, this could result in a tiny model.

Material properties

If you need to adjust position, rotation or the scale of materials within AutoCAD, do so using material properties rather than material mapping. Material mapping coordinates may not be always understood by other products, while Transforms within a material are exported in the material itself. This may mean you will need to create duplicates of a material when you need different rotation or scale, but it will save you time in Showcase.

Number of objects

When building your 3D model in AutoCAD, create some unions where possible, in order to have fewer objects for Showcase to manage.

Levels of detail

When importing a DWG file into Showcase, you are prompted for the level of detail. (See Adjust import conversion settings.) Depending on the model you are importing and the quality you need, it may be appropriate to select Large-Parts or Small-Details in the Change Conversion Settings window. If you need many details in part of your model and fewer in other parts, it may make sense to split the model into two DWG files (do a WBLOCK in AutoCAD and make sure not to change the origin), and import them with different levels of detail.

Reload

If, after exporting to Showcase, you make a change to your model in AutoCAD, the Import Status window in Showcase will display Need Reload in red text next to your file name. Click this text to get the latest version of your model. You can also replace the model with a different file (if you are saving incremental versions in AutoCAD) and change the level of detail from the import status window.

When you reload, Showcase zooms to the object you just reloaded. This is useful in exterior scenes, since you see what you just reloaded, but when you are already in an interior scene, you may end up behind a wall or other object. A solution for this is to create Showcase shots (press T) with the points of view you want to keep. You can add these shots to a Storyboard later.

If you make any changes to materials in Showcase and reload the model, Showcase will keep the changes you made and discard the material in the dwg file.