Hydra previewsuface display issue with displacement map

[dongyifan]

I have a terrain build by maya, it looks like this

The mesh is a simple plane, then use displacement map to get this result.

I try to get same result in Hydra with USD preview surface, but the result look like this

This is my USD file code (The mesh is a simple plane, so I remove mesh vertex and uv data since it is very noise):

#usda 1.0

def Mesh "pPlaneShape1"
{
    uniform bool doubleSided = 1
    float3[] extent = [(-0.5, -1.110223e-16, -0.5), (0.5, 1.110223e-16, 0.5)]
    int[] faceVertexCounts = []
    int[] faceVertexIndices = []
    point3f[] points = []
    float2[] primvars:st = [](
        interpolation = "vertex"
    )
    int[] primvars:st:indices = []
    float3 xformOp:scale = (24, 24, 24)
    uniform token[] xformOpOrder = ["xformOp:scale"]
    rel material:binding = </initialShadingGroup>
}

def Material "initialShadingGroup"
{
    token inputs:frame:stPrimvarName = "st"
    token outputs:surface.connect = </lambert1.outputs:surface>
    token outputs:displacement.connect = </lambert1.outputs:displacement>
}

def Shader "lambert1"
{
    uniform token info:id = "UsdPreviewSurface"
    color3f inputs:diffuseColor.connect = </diffuseTexture.outputs:rgb>
    float inputs:displacement.connect = </displacementTexture.outputs:r>
    token outputs:surface
    token outputs:displacement
}

def Shader "stReader"
{
    uniform token info:id = "UsdPrimvarReader_float2"
    token inputs:varname.connect = </initialShadingGroup.inputs:frame:stPrimvarName>
    float2 outputs:result
}

def Shader "diffuseTexture"
{
    uniform token info:id = "UsdUVTexture"
    asset inputs:file = @./textures/diffuse.jpg@
    float2 inputs:st.connect = </stReader.outputs:result>
    float3 outputs:rgb
    float outputs:r
}

def Shader "displacementTexture"
{
    uniform token info:id = "UsdUVTexture"
    asset inputs:file = @./textures/displacement.png@
    float2 inputs:st.connect = </stReader.outputs:result>
    float outputs:r
}

Does hydra preview surface support displacement map, or is there something wrong in my USD file?

This is the USD file

plane_displacement.usda.txt

Diffuse map and displacement map

[spiffmon]

Hi there! Apologies, most of us are at siggraph this week so responses may be a bit delayed. It would be helpful if you could actually attach the relevant portions of the usda file? Thanks! —spiff

On Tue, Jul 30, 2019 at 7:30 PM yifan ***@***.***> wrote: I have a terrain build by maya, it looks like this [image: IMG_3647] <https://user-images.githubusercontent.com/445204/62178878-22583200-b37d-11e9-89a0-e5de6085a919.jpg> The mesh is a simple plane, then use displacement map to get this result. I try to get same result in Hydra with USD preview surface, but the result look like this [image: IMG_3648] <https://user-images.githubusercontent.com/445204/62179013-8ed33100-b37d-11e9-9211-08d43c21e919.jpg> This is my USD file [image: IMG_3660] <https://user-images.githubusercontent.com/445204/62179062-c04bfc80-b37d-11e9-9ca8-e48eb729bee8.jpg> Does hydra preview surface support displacement map, or is there something wrong in my USD file. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#922>, or mute the thread <https://github.com/notifications/unsubscribe-auth/ABPOU2B4IBLZAEA7BDOS2LDQCD2K7ANCNFSM4IIB36ZQ> .

-- --spiffiPhone

[dongyifan]

Hi there! Apologies, most of us are at siggraph this week so responses may be a bit delayed. It would be helpful if you could actually attach the relevant portions of the usda file? Thanks! —spiff
On Tue, Jul 30, 2019 at 7:30 PM yifan @.***> wrote: I have a terrain build by maya, it looks like this [image: IMG_3647] https://user-images.githubusercontent.com/445204/62178878-22583200-b37d-11e9-89a0-e5de6085a919.jpg The mesh is a simple plane, then use displacement map to get this result. I try to get same result in Hydra with USD preview surface, but the result look like this [image: IMG_3648] https://user-images.githubusercontent.com/445204/62179013-8ed33100-b37d-11e9-9211-08d43c21e919.jpg This is my USD file [image: IMG_3660] https://user-images.githubusercontent.com/445204/62179062-c04bfc80-b37d-11e9-9ca8-e48eb729bee8.jpg Does hydra preview surface support displacement map, or is there something wrong in my USD file. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#922?email_source=notifications&email_token=ABPOU2CPLNEWLNE6NZZB3TTQCD2K7A5CNFSM4IIB36Z2YY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4HCOO6RQ>, or mute the thread https://github.com/notifications/unsubscribe-auth/ABPOU2B4IBLZAEA7BDOS2LDQCD2K7ANCNFSM4IIB36ZQ .
-- --spiffiPhone

Thanks for your reply, I have already update the comment, please take a look.

I put USD code into it and attache USD file with textures. if you want to reproduce, just create a folder named textures and put diffuse and displacement map into it.

[jilliene]

Filed as internal issue #USD-5474

[poljere]

Looks like you have hit an issue in our current implementation of previewSurface.glslfx. While we are fixing it internally, you can work around it by changing /pxr/usdImaging/lib/usdShaders/shaders/previewSurface.glslfx line 51 to :

float texDisplacement = HdGet_displacement(HdGet_st(index).xy).x;

Thanks!

[dongyifan]

Looks like you have hit an issue in our current implementation of previewSurface.glslfx. While we are fixing it internally, you can work around it by changing /pxr/usdImaging/lib/usdShaders/shaders/previewSurface.glslfx line 51 to :

float texDisplacement = HdGet_displacement(HdGet_st(index).xy).x;

Thanks!

Thanks for your support, This fix my problem.

[poljere]

Let's keep this open until we have a real fix for this issue, please remember that the workaround above will only work for texture coordinates coming from a primvar named "st".