Disable depth buffer writes while rendering smoke in the viewport.

Depth buffer values are used by the viewport pan and zoom code to
adjust response scaling factors between mouse and viewport movement.
Letting smoke write to the buffer confuses it and causes the camera
to get stuck and move very slowly inside smoke domains, because it
thinks it is very close to an object.

1 files changed, 5 insertions, 1 deletions

diff --git a/source/blender/editors/space_view3d/drawvolume.c b/source/blender/editors/space_view3d/drawvolume.c
index e93d840eddd..8dbc2788744 100644
--- a/source/blender/editors/space_view3d/drawvolume.c
+++ b/source/blender/editors/space_view3d/drawvolume.c
@@ -379,11 +379,13 @@ void draw_smoke_volume(SmokeDomainSettings *sds, Object *ob,
 
 	/* setup buffer and draw */
 
-	int gl_depth = 0, gl_blend = 0;
+	int gl_depth = 0, gl_blend = 0, gl_depth_write = 0;
 	glGetBooleanv(GL_BLEND, (GLboolean *)&gl_blend);
 	glGetBooleanv(GL_DEPTH_TEST, (GLboolean *)&gl_depth);
+	glGetBooleanv(GL_DEPTH_WRITEMASK, (GLboolean *)&gl_depth_write);
 
 	glEnable(GL_DEPTH_TEST);
+	glDepthMask(GL_FALSE);
 	glEnable(GL_BLEND);
 	glBlendFunc(GL_ONE, GL_ONE_MINUS_SRC_ALPHA);
 
@@ -422,6 +424,8 @@ void draw_smoke_volume(SmokeDomainSettings *sds, Object *ob,
 
 	GPU_shader_unbind();
 
+	glDepthMask(gl_depth_write);
+
 	if (!gl_blend) {
 		glDisable(GL_BLEND);
 	}