Dataprep - Some questions

Hi all,
I’ve been using Dataprep for just one day, and I was blown away by how much can be done, this is quite amazing!

Couple of questions, since I’m not sure for some things how to proceed:

  1. I’m using the “Filter by actor label” to get some of the parts, and it works great to merge actors, but I would like to do the following: I have 3 sub-assemblies which are basically the same thing, but placed inside my main assembly, so I would like to filter each one ( even though their name is the same ) and merge each one into separately, rather than a single big merged part. How do I do that?

  2. Create proxy mesh: is there a way to access the details for the material baking? I’ve used the Merge Actors tool a lot in the past, and there was tons of options, but here everything is set to default, so what if I want to change some settings within the Create Proxy Mesh?

  3. I exported the .STEP from Solid Edge and imported using the traditional Datasmith import option: I notice that objects with transparency are fine, but they can’t be turned 100% opaque for some reason.
    Even though I set the opacity level to 1, the mesh is still somehow a bit transparent…and I’m not sure if this is because of the meshes from Solid Edge being corrupted/badly optimized, or something else.

  4. ( This is more Datasmith related ): I usually have tons of nuts, washer and so on: does Datasmith consider them as instances? or it is something that I need to set?

Thanks in advance


  1. are your sub-assemblies actors in the outliner? You could filter them with the object name, that is unique, instead of the actor label.

  2. You cannot yet pass parameters to the merge or proxy mesh functions in visual data prep. At the moment you will have to run a blueprint / python script, in the editor, post commit of your visual dataprep

  3. If you want to make your material opaque you better replace it by an actual opaque version of your material. Either from your own library. If you want to use the datasmith material, make a material instance from the opaque version of the datasmith master material and change the base color accordingly.

  4. It will depend how those elements have been created in your CAD package. If they were setup properly datasmith should import a single static mesh for one type of your part and then have each actor using that part to refer to that single statich mesh. E.G. 10 AA nuts in your CAD scene => one AA static mesh and 10 actors.
    If you speak about the next level and refer to instanced static mesh components: where you have a single actor holding all the instance of a common part, you need to set that up yourself post datasmith import. E.G. 10 AA nuts in your CAD scene => one AA static mesh and one actor with instance static mesh component and 10 instances.

Hi Flavien,

Thanks for the reply.

  1. It works, but I notice a bug: if I copy/paste a New Action and I just change the “Filter by Object Name” I notice that the action themselves are not executed, but if I create the new action from scratch, they are executed

  2. Ok, sounds good but it’ll be grat to have a degree of access from Dataprep

  3. This is a weird issue, since if I try to change the default transparent material that Datasmith creates, the issue is still there, and even if I replace the material with a brand new one, the issue is still there…but I just tried to import everything with Dataprep, and changing the Master transparent material works…I’m not sure why

  4. Got it, thought it would automatically do the instancing of the parts all at once once those are recognized

Edit: Is it a bug or it is normal that after using the Merge function, the original merged geometry is still in the scene, overlapping the Merged mesh?

  1. This is strange, which version of the engine are you using?

  2. If you use a master material that is transparent, even though opacity is 100% you might have some unwanted effect when you look at facing triangles inside your geometry. This is why if you want a full opaque effect you are better with a material whose master use Opaque and not Transparent

Edit: I have been made aware that there are some original geometries that stay following a merge. That happens when you merge actors that hold static mesh components, not with static mesh actors. The original geometry should be gone after commit. This behaviour is not normal and checking with the team on how to best fix it.

1.I’m using 4.26.1, so if I try to Ctrl+mouse to copy a New Action, that action doesn’t do anything, only doing the entire Action from scratch…a bit time consuming, but it works

  1. Ok, will try that ( edit: solved using Dither Themporal AA )

About the edit: I’m getting the Object Name of a component ( which is a sub-assembly ), getting the childs with “Select Hierarchy”, then merge, and the child are all static meshes.

In general: My main goal is to drastically reduce the amount of draw calls in the scene. In my current setup ( done a couple of days ago without using DataPrep ) I used the Merge Actor Tool extensively, and I was able to group together meshes, and also bake the material, so that all the color information ( no textures in the scene, just RGB colors ) are baked into a single texture, drastically reducing the amount of draw calls.
Using DataPrep I’m using the Smaller than function to get rid of lots of small parts ( nuts, washers and so on ), but there are also functions within DataPrep to reduce draw calls by baking materials as well? this would be very beneficial, since it is a non-destructive approach that can be modified easily.