Guild of Writers

When I am exporting my age I keep getting

DAG zero.... not allowed to happen

It appears not to be an issue when it comes to the exported age.

It would probably help if I knew what DAG zero was.

I am not getting it where I have scratch built an age only where I have elements culled from my previous ages.

If this is not actually an issue do we need the message at all?

As I recall Hoikas telling me when I asked about this, it's a Blender warning that happens due to some changes in the internal data when using older Blender files. I'm not sure there's anything we can do about it, as it's not a Korman issue. Perhaps he can elaborate when he has more time (sadly, Hoikas is quite busy elsewhere these days).

A Headsup on the Wiki would be good.

Handy to know its an internal Blender message

Deledrius found something earlier today related to this issue, and I think I know how to fix it. The next Korman release is going to be a lot smaller, so hopefully it will happen in 2018.

Discovery

In an effort to speed up exporting I switched off Bake Static Lights

I stopped getting the DAG zero message.

I do not know if this helps.

Correction I don't get the message during export it is still appended at the end.

Some research into this "DAG zero... not allowed to happen" pointed it out as a glitch in blender.

I now have it popping up a second time in the reporting of my export between the lines

Collecting Objects
and
Harvesting Actors

I suppose it is something we will probably have to live with considering it is embedded in Blender rather than Korman and it appears not to intefere significantly with the exporting.

I am continually left wondering what is the line it is overwriting?

What is the DAG that is not allowed?

Plus we are told the time spent exporting in seconds and while this is probably useful in some ways I would also like to see the numbers of whatever.

Its no big deal and if it is a big issue I am more than prepared to ignore it considering the export works.

I can remember i experienced this problem in the past.
I think it happened after importing some objects from older blendfiles which contains some dependecies not longer available in the new environment.

May be this piece of code clears it up for the coders amoung us.

Code: Select all

/* flushes all recalc flags in objects down the dependency tree */
void DAG_scene_flush_update(Main *bmain, Scene *sce, unsigned int lay, const short time)
{
    DagNode *firstnode;
    DagAdjList *itA;
    Object *ob;
    int lasttime;

    if (!DEG_depsgraph_use_legacy()) {
        DEG_scene_flush_update(bmain, sce);
        return;
    }

    if (sce->theDag == NULL || sce->theDag->need_update) {
        printf("DAG zero... not allowed to happen!
");
        DAG_scene_relations_update(bmain, sce);
    }
.......

This message sounds relatively harmless though. From what little I can gather, it seems it's related to Blender cleaning up some orphaned data or something. That might happen due to all the data Korman is shuffling around behind the scenes when you export an Age (like making temporary versions of meshes with modifiers applied, baking lightmaps, etc).
This shouldn't be much of a concern until some objects actually start disappearing from your Blender files... Or some objects refuse to get deleted, like J'Kla's toilets But like I said, I don't think it's too serious.

https://github.com/H-uru/korman/commit/ ... da18819a21

In the meantime, if this is really bothering you, I suggest starting Blender with the new dependency graph by using the --enable-new-depsgraph argument.

I've literally seen this message hundreds of times after export and it doesn't affect the Age one bit from what I've seen. I wouldn't worry about it.