[4.8] Update Instance Transform - scale not working

anonymous_user_cacd3de0 · June 12, 2015, 1:58am

I have some blueprint that calls updateInstanceTransform with a new scale value. 4.8 is broken. Worked fine in 4.7.

anonymous_user_a08c0bf2 · June 12, 2015, 6:27pm

Hey Steve,

Could you please provide us a screenshot of the blueprint that you’re having trouble with? With this information, we’ll be able to reproduce this in house and provide any information, or report a bug to our developers.

Thanks!

anonymous_user_cacd3de0 · June 14, 2015, 12:56am

It should be easy to reproduce. I don’t have a simple screenshot. Create a bunch of instanced meshes, then do a for loop and update the transform with a scale of .5,.5,.5 or whatever and nothing happens. it worked fine it 4.7.

anonymous_user_a08c0bf2 · June 15, 2015, 5:54pm

Hey ,

I have set up a blueprint that allows scaling of a static mesh. I am not able to replicate what you’re stating is occurring, which is why it would be really helpful if I had your blueprint to reference. If you’re able to provide me with a screenshot of your blueprint, I’ll be able to test this out in house and submit a bug to our developers if it’s not working.

Thank you and have a wonderful day!

anonymous_user_cacd3de0 · June 16, 2015, 12:17am

See that? Took me 5 seconds to reproduce it. Works fine in 4.7.6, fails if using 4.8

anonymous_user_a08c0bf2 · June 16, 2015, 2:20pm

Hello,

I have recreated this blueprint exactly as described and have verified the bug in 4.8.0. This report can be referenced as: UE-17119

Thank you for noticing the issue, have a great day.

grall69_1 · June 16, 2015, 3:25pm

It’s not only the scale. The location too.

anonymous_user_a08c0bf2 · June 16, 2015, 3:40pm

Thank you, I’ve updated the report with the following information!

anonymous_user_550b73f9 · June 19, 2015, 8:41am

Hi grall69,

If you check the “Mark Render State Dirty” checkbox the transform will update. This was added to improve performance problems when updating many instances. I don’t think it should default to false however.

I’ll add a tooltip to make sure the functionality is documented.

Cheers

anonymous_user_cacd3de0 · June 19, 2015, 9:10am

Thanks! That fixed it.

anonymous_user_cacd3de0 · June 19, 2015, 8:39pm

Just wondering the proper way to use this. Should we only check that checkbox on the last instance we are updating to optimize performance? Why wouldn’t you always have this checked?

anonymous_user_550b73f9 · June 22, 2015, 2:21am

If you’re updating a handful of instances it won’t make any noticeable difference. But if you’re updating hundreds in a single frame, I guess you could get slightly better performance only setting the checkbox on the final instance.

Looking at the code, I can’t really see much benefit at all. The checkbox was added in a pull request (a submission). I’m going to follow up with the engineer who integrated the change to find out more details as to exactly why it was added.

Cheers

grall69_1 · June 23, 2015, 1:04am

Yeah, it’s fixed for me too after checked the last Instance.
And looks like better (I was on 4.6.1).

Thanks a lot .