New Renderer

The new renderer is actually fairly basic in terms of what's already out there, but it serves its purpose. For one it's based entirely on the fixed function pipeline, I'm not sure yet whether I'll write any shaders for this project, for the time being basic FFP stuff is serving me well.

At the highest level the renderer takes a list of skeletons to render, paired off with their current frame given as a pose instance. It configures the pipeline and iterates the list, extracting their hierarchy instances and sending it off along with the pose frame to a function dedicated to drawing skeletons. The function recurses the hierarchy, extracting the quaternion rotation from the relevant bone/joint pose description, concatenates it together with the parent transform as a matrix to get the joint transform for the bone and forwards that onto a bone renderer along with with the resting bone vector. This renderer uses the bone vector to calculate the resting direction and length of the bone (currently using an expensive sqrt), converts those to appropriate rotation and scaling matrices (using dot and cross products ) and concatenates them with the joint transform given to it previously to arrive, eventually, at the bone's final world-space transformation that turns a unit-sphere mesh into a bone. When calculating the scaling the thickness of the bone is calculated to be 0.3 times its height, it seems that a number of other academic skeleton renderers do something similar as it produces a familiar looking skeletal figure with the very tiny heads and feet.

The high-level renderer does this twice, once for the main skeleton and again, with inverted z-axis and culling winding order, to get the reflection. It then uses an arena renderer to draw a checkered, semi-transparent floor.

There are still improvements needed to the renderer, I don't really like performing square roots etc in the renderer, I might move this work to the animation tree if I can. In addition there is no instancing going on, it should be possible to instance the sphere mesh to draw the bones of the skeletons. Having the renderer accept a list of skeleton-pose pairs is a little hacked together at the moment too, it just needs a tidy-up. My supervisor has also requested that I try and use a proper model for the scene too, so I might have a go at getting .X-files working. Whether or not I decide to write any shaders for the renderer remains to be seen, certainly a lot work could be moved to shaders but I don't know HLSL at all so we'll see.

The renderer, as it stands, is pretty complete it terms of how I envisioned it initially, I hadn't planned to do any more than this. It has all the features that I said it would a few blog posts previously, so I'm pleased it has got this far.

That's all again for now, I'll leave with a screenshot of the new renderer displaying some skeletons, you can see it in motion a few blog posts down too.