Cineversity

Joint and Skin Deformer Priority

Hi,

I initially thought Joint and Skin Deformer priorities should always go hand in hand but I just noticed that joint object has its own priority.

In what case would the joint object’s priority be different than its corresponding skin deformer?

I checked the online help but Joint>Priority Section is left blank.

Hi Ben,

The Skin Deformer needs information from the joints. Which means that the joints need to be calculated first (lower priority). If the Skin Object were calculated before the joints, the mesh would be at least one frame behind.

Please note, it might work in the editor view, as after each action taken the scene is refreshed, so information that would be otherwise received from the frame before is available in this very same frame, based on repeated calculations. What counts is the render time, there is only a one-time calculation per frame, and there the sequence is critical.

All the best

Hi @Dr. Sassi

To edit post above: By default the joint has a priority of [removed]0) and the Skin has a priority of Generators (-1) (i.e. they are actually different from the start and not the same)

Thanks for the response.
So, I guess to confirm, for a related skin deformer and joints, there is no way the joints should have higher priority than the skin (i.e. joints with Generator -2 and the Skin with a Generator -1?

Is this assessment correct?

Ben,

Joints that feed information to a Skin Object need to be lower in Priority; otherwise, they get calculate after it. The Skin Object would use then the information from the previous frame.

If “…joints with Generator -2 and the Skin with a Generator -1…” is the case, that is working, as the Joints have a lower priority. However, this is not suggested, as there is no space anymore between the two. It leaves only the same Priority for other related objects and so based a Priority level only based on the position in the Object Manager or if Xpresso is in the mix, the place in the X-Manager. Not a good idea, on re-organization in the Object Manager, and the scene falls apart perhaps.

Just to be clear, for anyone reading along if there is not a single very urgent demand for Generator level and Joints, leave them out of that high Priority level.

Cheers