From e1827b1e37037627a8f2f136e72dad62c6a23f1e Mon Sep 17 00:00:00 2001
From: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Date: Tue, 4 Jun 2019 23:42:34 -0700
Subject: [PATCH] Fix skinning precision issue on iOS

On iOS, by default the bones that are sampled from the bone texture look
like they are using mediump. This can result in noticeable jitter or
other more severe issues depending on the bone transformation matrix.

Fix this by explicitly declaring the sampler as highp.
---
 src/renderers/shaders/ShaderChunk/skinning_pars_vertex.glsl.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/renderers/shaders/ShaderChunk/skinning_pars_vertex.glsl.js b/src/renderers/shaders/ShaderChunk/skinning_pars_vertex.glsl.js
index 0b972c0f126eee..9f9097145641d3 100644
--- a/src/renderers/shaders/ShaderChunk/skinning_pars_vertex.glsl.js
+++ b/src/renderers/shaders/ShaderChunk/skinning_pars_vertex.glsl.js
@@ -6,7 +6,7 @@ export default /* glsl */`
 
 	#ifdef BONE_TEXTURE
 
-		uniform sampler2D boneTexture;
+		uniform highp sampler2D boneTexture;
 		uniform int boneTextureSize;
 
 		mat4 getBoneMatrix( const in float i ) {