Wiring Up

The first step is to create a C# wrapper for the Collada DOM.

I started by creating a static build of the Collada DOM DLL, which is then imported into a CLI/C++ project. This wrapper project is able to handle communication between native code (the Collada DOM in this case) and managed code. Fortunately it was not necessary to wrap the entire Collada DOM, just a few methods of the DAE and daeElement classes with some string marshalling thrown in. The end result is a self-contained .NET assembly exposing the Collada DOM to any .NET language.

All I need to do now is code the exporter. I started with a simple model with a distinctive shape (pictured left). This arrow turned out to be extra useful for tackling axis-alignment in the next step.

First Import

My first pass at the exporter creates a tidy .dae file which Blender opens without any complaints. I love it when code works first run.

I did notice however the arrow was no longer pointing along the correct axis. The reason for this is that Blender uses +Z for up and XNA uses +Y for up. A quick scan of the Collada spec and forums shows this is a common issue with an easy solution. My exporter class is updated so that any axis can be considered up. This is achieved with a rotation on the model node and setting the <up_axis> in <asset> to reflect the appropriate setting.

With the model vertices in place, it’s now time to add textures.

Textured Models

This was more work than I expected. Each set of triangles references a material, each material instantiates an effect, every effect points to an image, which in turn points to a file on disk. Oh, and the materials have to be bound to the model in the scene setup.

Once my head stopped spinning from all the redirection, I could see the versatility of this method. I was also impressed how detailed scenes can be constructed using Collada, right down to cameras and lights. I want to look into exporting blocks, cities, and dungeons to Collada files at a later date.

On the left are a few screenshots of some distinctive Daggerfall models as viewed in Blender.

Thumbnails

This has been tweaked since my last post. I’ve selected a different viewing angle to give more of a 3/4 view of each model rather than a frontal view. I have disabled back-face culling to ensure a thumbnail is rendered even when facing away from the camera. The overall effect is that almost all thumbnails show a decent representation of the model that’s easy for the eye to track.

Thumbnails are generated in real-time from model data. I plan to add a few embelishments like watching the model spin when the mouse passes over a thumbnail.

Scrolling the thumbnail view can be performed from your mouse wheel or by dragging the page as you would the touch screen of an iPhone. You can impart velocity to the scroll with a flick of the mouse. The view will keep scrolling until you grab it again or roll the mouse wheel.

The thumbnail view isn’t just for viewing thousands of models either. When you have a city or dungeon loaded, you can switch over to thumbnails to view just the models used for that location. This filtered list of thumbnails will be helpful for finding the exact model to export in large areas where models can be duplicated dozens of times.

If you double-click on a thumbnail, it takes you straight to our next view, the Single Model View.

Single Model View

After finding a model in the thumbnails view, you can explore that model in greater detail. This view is similar to the model view in Daggerfall Explorer.

It is possible to search for individual models by ID (check the left-hand pane of top screenshot).

When viewing a location, you can also jump to single model view by clicking on any model within the location itself. Daggerfall Modelling uses bounding volumes so you can pick any model right out of the scene.

Location View – Top-Down Camera

The first way of viewing locations is the default top-down camera. This camera is always facing down on the scene and you scroll around as you would a 2D map. Clicking on a specific block in the map (screenshot) will take you directly to that block.

If you’re only interested in one block, you will be able to filter out everything but the block you’ve clicked on.

When you see a model you’re interested in, you can switch to inspecting that model in the Single Model View without losing your place in the Location View (unless you change locations).

Location View – Free Camera

The free camera allows you to move around in first-person mode through city streets or narrow dungeon corridors. Pictured left is the city of Sentinel (top) and Mantellan Crux (bottom).

The Mantellan Crux screenshot shows how the dungeon layout map is displayed. Each square represents a dungeon block. Currently the starting block (dungeon entrance) is blue-green, and other blocks are gold. The RGB values match those used in Daggerfall to display dungeon layouts.

Before this tool is completed, I plan to implement an “interior view” so you can crack open building interiors to select the furniture and other models within.