Normal map support in Cycles standalone #49573

New Issue

Jeff Witthuhn · 2016-10-05T01:04:33+02:00

Jeff Witthuhn commented

2016-10-05 01:04:33 +02:00

System Information
Windows 8.1 64-bit

Cycles Version
d553b8de7180

Short description of error

In the latest version available in the Cycles standalone repository, commit d553b8de7180, using a normal map node in a shader graph will cause Cycles to crash. This behavior was not present in release 1.7.0 but has been added since then.

This looks to be caused by an improperly initialized member variable in the ccl::NormalMapNode type. Upon creating an object of type NormalMapNode, the ustring named 'attribute' is initialized such that attribute.c_str() will return a nullptr.

Cycles crashes when the nullptr used to construct a std::string in NormalMapNode::attributes in this bit:

		else {
			attributes->add(ustring((string(attribute.c_str()) + ".tangent").c_str()));
			attributes->add(ustring((string(attribute.c_str()) + ".tangent_sign").c_str()));
		}

Exact steps for others to reproduce the error

I have attached a simple cycles standalone scene that triggers this error here: sample_scene.xml

**System Information** Windows 8.1 64-bit **Cycles Version** d553b8de7180 **Short description of error** In the latest version available in the Cycles standalone repository, commit d553b8de7180, using a normal map node in a shader graph will cause Cycles to crash. This behavior was not present in release 1.7.0 but has been added since then. This looks to be caused by an improperly initialized member variable in the ccl::NormalMapNode type. Upon creating an object of type NormalMapNode, the ustring named 'attribute' is initialized such that attribute.c_str() will return a nullptr. Cycles crashes when the nullptr used to construct a std::string in NormalMapNode::attributes in this bit: ``` else { attributes->add(ustring((string(attribute.c_str()) + ".tangent").c_str())); attributes->add(ustring((string(attribute.c_str()) + ".tangent_sign").c_str())); } ``` **Exact steps for others to reproduce the error** I have attached a simple cycles standalone scene that triggers this error here: [sample_scene.xml](https://archive.blender.org/developer/F374015/sample_scene.xml)

Jeff Witthuhn commented

2016-10-05 01:04:33 +02:00

Changed status to: 'Open'

Jeff Witthuhn commented

2016-10-05 01:04:33 +02:00

Added subscriber: @witthuhn

Sergey Sharybin commented

2016-10-11 17:52:03 +02:00

Added subscribers: @ThomasDinges, @Sergey

Thomas Dinges was assigned by Sergey Sharybin

2016-10-11 17:52:03 +02:00

Sergey Sharybin commented

2016-10-11 17:52:03 +02:00

AFAIR, normal map requires tangent space, which in Blender is calculated using mikkspace. This library is not used by the standalone Cycles. So making normal map to work is a bit involved, but think we should still fix the crash.

@ThomasDinges, something fun for you to look into? ;)

AFAIR, normal map requires tangent space, which in Blender is calculated using mikkspace. This library is not used by the standalone Cycles. So making normal map to work is a bit involved, but think we should still fix the crash. @ThomasDinges, something fun for you to look into? ;)

kalpesh commented

2019-02-22 10:22:35 +01:00

Added subscriber: @kalpesh-2

kalpesh commented

2019-02-22 10:22:35 +01:00

Is this being addressed? Have a lot of gltf 2.0 assets with tangent space normal maps that just render black (no crash though). boombox.zip

Is this being addressed? Have a lot of gltf 2.0 assets with tangent space normal maps that just render black (no crash though). [boombox.zip](https://archive.blender.org/developer/F6685467/boombox.zip)

Thomas Dinges was unassigned by Dalai Felinto

2019-12-23 16:36:58 +01:00

Brecht Van Lommel changed title from ~~Crash when using normal map node in cycles standalone~~ to Normal map support in Cycles standalone

2020-02-12 11:22:48 +01:00

Brecht Van Lommel commented

2020-02-12 11:23:10 +01:00

Added subscriber: @brecht

Brecht Van Lommel commented

2020-02-12 11:23:10 +01:00

The solution here would be to move the tangent computation from the Blender exporter into Cycles itself.

Brecht Van Lommel added this to the Render & Cycles project 2023-02-07 19:07:34 +01:00

Philipp Oeser removed the

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Normal map support in Cycles standalone #49573