…odent.xml.

- This model has a bunch of ranges defined (tendon length ranges and actuator force-limit ranges) that are actually inactive due to the associated "limited" property not being set to "true".
- A recent change in MuJoCo enabled automatically inferring the "limited" property according to the presence of the associated "range" property, which changed the behaviour of this model and helped us realise the above situation.
- This CL explicitly disables tendon ranges limits and actuator force limits while leaving the ranges in place, so the model behaviour remains unchanged.
- Since many of the numbers seem to be carefully calibrated, it might be worth investigating in the future whether the limits should actually be activated.

PiperOrigin-RevId: 468690429
Change-Id: Icd097a2cafe15e910bca71c5378bddcf3d92665a

Before this change, setting any keyword attribute to False meant the attribute wasn't specified at all. This is fine for attributes where the default is false, but wrong for other keyword attributes.

In particular, since commit google-deepmind/mujoco@4bfc2c0, ctrllimited and similar attributes changed their default value from "false" to "auto", breaking some models that specify forcelimited=False and forcerange=something.

Also in this commit: update the ctrllimited and similar attributes' schemas to include the value "auto".

PiperOrigin-RevId: 468699407
Change-Id: I7f64d2e757678a00aec8b1cfa33894ac1b7f5b5b

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Change-Id: I60d239051e8bbded0f90add424418f7bd5c63c2f

- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.

PiperOrigin-RevId: 469190483
Change-Id: Idf5928fbf278fb10357a77d2de2455d4a525d95a

- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.

PiperOrigin-RevId: 469228149
Change-Id: I2863b8a52b35bc562d37fd2d779dd8b8f0bea24a

PiperOrigin-RevId: 469473066
Change-Id: I0a6e4370f93d47033630a86be988804062b6c273

- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.

PiperOrigin-RevId: 470021901
Change-Id: I14226e80b8ed65580822186e55995810033ad757

- Added `refsite` attribute to actuators with `site` transmission.
- Such actuators now have a well defined length and can be used for e.g., Cartesian end-effector control.
- Added example models and documentation describing the new feature.

PiperOrigin-RevId: 471561218
Change-Id: I969c93a21d9a517a75e6ee013d4ebe3146ee48d3

This is to prevent conflict with TensorFlow. Fixes google-deepmind#339.

PiperOrigin-RevId: 472258727
Change-Id: I886360eb687d62192bad2ccb94266c207efd2050

Fixes google-deepmind#310.

PiperOrigin-RevId: 472296006
Change-Id: I558c1fdf3753ed660f4463ae2dc054f496164c8a

This is an amendment to 4bfc2c0311233017293748e558a114a510a21f91.

Add an autolimits compiler option. When true, *limited will be inferred from the presence of the *range attributes.
When false, models where limited is not specified, and range is will fail to compile.

PiperOrigin-RevId: 472438650
Change-Id: Ia76247064e54f9f876061d8455f84cb939e7d73e

PiperOrigin-RevId: 472485161
Change-Id: Ic5fa30c97e1a33b6e0c8878818d0f51539795acb

PiperOrigin-RevId: 472678116
Change-Id: I754ae8817c41bebbaab41c5e439dfd1d6518a822

The viewer has its own set of default renderer flags, and when the `mjRND_CULL_FACE` flag was introduced in MuJoCo (google-deepmind/mujoco@396fdf0) the viewer's default was not updated.

Fixes google-deepmind#346.

PiperOrigin-RevId: 472753294
Change-Id: I33e6f48ff1ea887d07765ae851651f6c106cb08b

PiperOrigin-RevId: 474874088
Change-Id: I1bbcc20439dc59de7e18327a2cdc6fad0a57201e

PiperOrigin-RevId: 475600801
Change-Id: Id298b3614ad67fcb707500fbcb2d87e0f7b58bce

…/assets/`.

- Preparation for improved dog model.
- Added dog_base.xml with all the defaults.
- Moved floor and tennis ball to scene.xml, removed target.

PiperOrigin-RevId: 476119984
Change-Id: I8c5e836fe61956872973528659137fe74045badc

…except for camera_id, which has to be -1.

PiperOrigin-RevId: 478002851
Change-Id: I78253a2887073490cfbd92e4295eb0539003d710

PiperOrigin-RevId: 478117894
Change-Id: Iedb1f1083bfcbbb7d8643973444b7f0e2c219107

- Add private function `mj_arenaAlloc`. This is used internally to allocate memory from the arena.

- Add private function `mj_nefc` to count constraints. This function returns a tight upper bound on `d->nefc`. The number of counted constraints can be slightly bigger than exact `d->nefc` in the case of constraints with empty Jacobian, as when placing a frictional tendon between two world sites.

- Add new `memory` attribute to the `size` XML element for specification of arena memory size. This attribute is mutually exclusive with `nstack` and `njmax` specifications, which are now deprecated (but left around for the time being for legacy compatibility).

- Move `d->stack` to the end of the new arena space. The stack now grows in reverse from the end.

PiperOrigin-RevId: 479341539
Change-Id: I27f67d524607db71e24f714dc96b221c0448795e

…hese are lists and the time variable clashes with the imported time and causes errors.

PiperOrigin-RevId: 479538684
Change-Id: If9a47d1a4b84636435bcc980a4563ee7d2871fd1

…dlers.

PiperOrigin-RevId: 481106930
Change-Id: Ib2645050ae2757759b4aac87887e965a6716c092

PiperOrigin-RevId: 481885969
Change-Id: I5030c6daef18afcc7367200531ed7a68207cad8b

PiperOrigin-RevId: 482699032
Change-Id: Iefbc093544d48d3020d6ecbb400f44503028e620

…h the spring produces no force (a deadband).

If given two non-decreasing values, `springlength` specifies a deadband for spring stiffness, inside of which the force is 0 and outside of which force behaves like a regular spring, with the setpoint corresponding to the nearest value. This can be used to create tendons whose limits are enforced by springs rather than constraints, which are cheaper and easier to analyse. See test/engine/testdata/tendon_springlength.xml example model.

Spring-limited spatial tendons whose lower range value is 0 are rendered as catenaries.

Fixes google-deepmind#520.

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Change-Id: I821465553c69bf8ea76a55452a4fb79563fdb7c3

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Change-Id: Icbb01086db33aef2bcf199df89e8b6069e26974c

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Change-Id: Id9acf63205941ac9ac2f87ec30099bff4ec0f1b7

… `user`.

Fixes google-deepmind#305.

PiperOrigin-RevId: 486597273
Change-Id: I0b5913622c1d2e8297427d4ffe34cf8bfd70ec5e

… and steps physics.step.

PiperOrigin-RevId: 486675254
Change-Id: Ib6b70e707354f89679db90371dcc315f7a8ae18f