blender
/
blender
136
405
Fork 586
Code Issues 6.2k Pull Requests 757 Projects 19 Wiki Activity

USD export: add scale and bias for normal maps. 

Changes authored by Michael B Johnson (drwave).

This addresses the issue in T102911.

Add scale and bias inputs to ensure the normals are
in tangent space [(-1,-1,-1), (1,1,1)].

This is following the convention as set in the USD Spec
(https://graphics.pixar.com/usd/dev/spec_usdpreviewsurface.html).

Differential Revision: https://developer.blender.org/D17072
This commit is contained in:
Michael Kowalski 2023-01-30 11:32:03 -05:00
parent ad083f925c
commit c79b55fc05
Notes: blender-bot 2023-02-14 03:31:57 +01:00 
Referenced by issue #102911, USD exporter does not conform to usdpreviewsurface spec for normal maps
1 changed files with 38 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
source/blender/io/usd/intern/usd_writer_material.cc
View File

@ -61,6 +61,8 @@ static const pxr::TfToken normal("normal", pxr::TfToken::Immortal);
static const pxr::TfToken ior("ior", pxr::TfToken::Immortal);
static const pxr::TfToken file("file", pxr::TfToken::Immortal);
static const pxr::TfToken raw("raw", pxr::TfToken::Immortal);
static const pxr::TfToken scale("scale", pxr::TfToken::Immortal);
static const pxr::TfToken bias("bias", pxr::TfToken::Immortal);
static const pxr::TfToken sRGB("sRGB", pxr::TfToken::Immortal);
static const pxr::TfToken sourceColorSpace("sourceColorSpace", pxr::TfToken::Immortal);
static const pxr::TfToken Shader("Shader", pxr::TfToken::Immortal);
@ -114,6 +116,7 @@ static bNode *traverse_channel(bNodeSocket *input, short target_type);
template<typename T1, typename T2>
void create_input(pxr::UsdShadeShader &shader, const InputSpec &spec, const void *value);
void set_normal_texture_range(pxr::UsdShadeShader &usd_shader, const InputSpec &input_spec);
void create_usd_preview_surface_material(const USDExporterContext &usd_export_context,
Material *material,
pxr::UsdShadeMaterial &usd_material,
@ -162,6 +165,7 @@ void create_usd_preview_surface_material(const USDExporterContext &usd_export_co
preview_surface.CreateInput(input_spec.input_name, input_spec.input_type)
.ConnectToSource(created_shader.ConnectableAPI(), input_spec.source_name);
set_normal_texture_range(created_shader, input_spec);
}
else if (input_spec.set_default_value) {
/* Set hardcoded value. */
@ -200,6 +204,40 @@ void create_usd_preview_surface_material(const USDExporterContext &usd_export_co
}
}
void set_normal_texture_range(pxr::UsdShadeShader &usd_shader, const InputSpec &input_spec)
{
/* Set the scale and bias for normal map textures
* The USD spec requires them to be within the -1 to 1 space
* */
// Only run if this input_spec is for a normal
if (input_spec.input_name != usdtokens::normal)
return;
// Make sure this is a texture shader prim
pxr::TfToken shader_id;
if (!usd_shader.GetIdAttr().Get(&shader_id) || shader_id != usdtokens::uv_texture)
return;
// We should only be setting this if the colorspace is raw. sRGB will not map the same.
pxr::TfToken colorspace;
auto colorspace_attr = usd_shader.GetInput(usdtokens::sourceColorSpace);
if (!colorspace_attr || !colorspace_attr.Get(&colorspace) || colorspace != usdtokens::raw)
return;
// Get or Create the scale attribute and set it
auto scale_attr = usd_shader.GetInput(usdtokens::scale);
if (!scale_attr)
scale_attr = usd_shader.CreateInput(usdtokens::scale, pxr::SdfValueTypeNames->Float4);
scale_attr.Set(pxr::GfVec4f(2.0f, 2.0f, 2.0f, 2.0f));
// Get or Create the bias attribute and set it
auto bias_attr = usd_shader.GetInput(usdtokens::bias);
if (!bias_attr)
bias_attr = usd_shader.CreateInput(usdtokens::bias, pxr::SdfValueTypeNames->Float4);
bias_attr.Set(pxr::GfVec4f(-1.0f, -1.0f, -1.0f, -1.0f));
}
void create_usd_viewport_material(const USDExporterContext &usd_export_context,
Material *material,
pxr::UsdShadeMaterial &usd_material)