Custom expresion dx12

Development Rendering
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1

I use gdc plugin for volumetrick material and when switch to dx12 I have error:
[SM5] Shader attempted to bind the Primitive uniform buffer even though Vertex Factory FLocalVertexFactory computes a PrimitiveId per-instance. This will break auto-instancing. Shaders should use GetPrimitiveData(Parameters.PrimitiveId).Member instead of Primitive.Member.

I try fix it but I havent any reference with GetPrimitiveData how it use

2

primitive replace by GetPrimitiveData(Parameters.PrimitiveId)

3

Did you get it to work? It seems to be connected to transformposition (local to world space) node I think? It broke octahedral impostors for me in 4.22

4

Can you take a screenshot?

5

Hi, I got the same issue here too, how can we fix this issue?

6

This the old code that needs to be updated :

#if USE_INSTANCING || IS_MESHPARTICLE_FACTORY
		return mul(InWorldVector, transpose(Parameters.InstanceLocalToWorld));
	#else
		return mul(InWorldVector, (MaterialFloat3x3)Primitive.WorldToLocal);
	#endif

I’m no programmer and not sure how to update to code to make this work.

7

To clarify this answer, as it is correct, but not descriptive. Basically anywhere it says “Primitive” replace that word and only that word with “GetPrimitiveData(Parameters.PrimitiveId)”

Here is the Documentation: Mesh Drawing Pipeline Conversion Guide for Unreal Engine 4.22 | Unreal Engine Documentation
Scroll all the way to the bottom.

Ex:
localcampos = (localcampos / (Primitive.LocalObjectBoundsMax.x)) ;

Becomes:
localcampos = (localcampos / (GetPrimitiveData(Parameters.PrimitiveId).LocalObjectBoundsMax.x;

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