[Bf-blender-cvs] [d97e586f58b] blender-v2.93-release: Geometry Nodes: Fix vector math project bug

[Charlie Jolly]

Commit: d97e586f58ba24e16f0df5dcfe73b5d505b889e9
Author: Charlie Jolly
Date:   Mon Jul 26 11:00:58 2021 +0100
Branches: blender-v2.93-release
https://developer.blender.org/rBd97e586f58ba24e16f0df5dcfe73b5d505b889e9

Geometry Nodes: Fix vector math project bug

Implementation is incorrect compared to Cycles/Eevee.

Reported by @DrDubosc in comments of T88922.

Differential Revision: https://developer.blender.org/D12029

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M	source/blender/nodes/NOD_math_functions.hh

===================================================================

diff --git a/source/blender/nodes/NOD_math_functions.hh b/source/blender/nodes/NOD_math_functions.hh
index 45de1816549..54608b4cfca 100644
--- a/source/blender/nodes/NOD_math_functions.hh
+++ b/source/blender/nodes/NOD_math_functions.hh
@@ -266,7 +266,7 @@ inline bool try_dispatch_float_math_fl3_fl3_to_fl3(const NodeVectorMathOperation
       return dispatch([](float3 a, float3 b) { return float3::cross_high_precision(a, b); });
     case NODE_VECTOR_MATH_PROJECT:
       return dispatch([](float3 a, float3 b) {
-        float length_squared = float3::dot(a, b);
+        float length_squared = float3::dot(b, b);
         return (length_squared != 0.0) ? (float3::dot(a, b) / length_squared) * b : float3(0.0f);
       });
     case NODE_VECTOR_MATH_REFLECT: