I am trying to make an entity that is basically a horse, and I want the riding player to be able to jump.

Currently I implemented IJumpingMount, and copied the Horse code (modified a bit).

Current travel method:

@Override
    public void travel(Vec3d movement) {
        if (this.isBeingRidden() && !isSitting()) {
            LivingEntity livingentity = (LivingEntity) this.getPassengers().get(0);
            this.rotationYaw = livingentity.rotationYaw;
            this.prevRotationYaw = this.rotationYaw;
            this.rotationPitch = livingentity.rotationPitch * 0.5F;
            this.setRotation(this.rotationYaw, this.rotationPitch);
            this.renderYawOffset = this.rotationYaw;
            this.rotationYawHead = this.renderYawOffset;
            float f = livingentity.moveStrafing * 0.5F;
            float f1 = livingentity.moveForward;
            if (f1 <= 0.0F) {
                f1 *= 0.25F;
            }

            if (this.jumpPower > 0 && !this.isJumping && onGround) {
                double d0 = 0.85f * (double) this.jumpPower;
                double d1;
                if (this.isPotionActive(Effects.JUMP_BOOST)) {
                    d1 = d0 + (double) ((float) (this.getActivePotionEffect(Effects.JUMP_BOOST).getAmplifier() + 1) * 0.1F);
                } else {
                    d1 = d0;
                }

                Vec3d vec3d = this.getMotion();
                this.setMotion(vec3d.x, d1, vec3d.z);
                this.setJumping(true);
                this.isAirBorne = true;
                if (f1 > 0.0F) {
                    float f2 = MathHelper.sin(this.rotationYaw * ((float) Math.PI / 180F));
                    float f3 = MathHelper.cos(this.rotationYaw * ((float) Math.PI / 180F));
                    this.setMotion(this.getMotion().add(-0.4F * f2 * this.jumpPower, 0.0D, (0.4F * f3 * this.jumpPower)));
                    this.playSound(SoundEvents.ENTITY_HORSE_JUMP, 0.4F, 1.0F);
                }

                this.jumpPower = 0.0F;
            }

            this.jumpMovementFactor = this.getAIMoveSpeed() * 0.1F;
            if (this.canPassengerSteer()) {
                this.setAIMoveSpeed((float) this.getAttribute(SharedMonsterAttributes.MOVEMENT_SPEED).getValue());
                super.travel(new Vec3d(f, movement.y, f1));
            } else if (livingentity instanceof PlayerEntity) {
                this.setMotion(Vec3d.ZERO);
            }

            if (this.onGround) {
                this.jumpPower = 0.0F;
                this.setJumping(false);
            }

            this.prevLimbSwingAmount = this.limbSwingAmount;
            double d2 = this.posX - this.prevPosX;
            double d3 = this.posZ - this.prevPosZ;
            float f4 = MathHelper.sqrt(d2 * d2 + d3 * d3) * 4.0F;
            if (f4 > 1.0F) {
                f4 = 1.0F;
            }

            this.limbSwingAmount += (f4 - this.limbSwingAmount) * 0.4F;
            this.limbSwing += this.limbSwingAmount;
        } else {
            this.jumpMovementFactor = 0.02F;
            super.travel(movement);
        }
    }

I know the y motion is set to .85, but the animal is not jumping. They can move around correctly when I press WSAD, but not jump.

I tried setting d0 to 0 outside of the if, and using 

super.travel(new Vec3d(f, movement.y+d0, f1));

but still no y movement.