• Welcome to World Machine Community. Please login or sign up.
June 16, 2019, 04:37:06 pm


Read the Development Diary for an inside look at World Machine's progress!

Triangle reduction apparently not working?

Started by Eric Cosky, July 07, 2011, 11:56:37 am

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Eric Cosky

In the attached scene, the exported OBJ files do not appear to have had triangle reduction applied. I get the same results with & without the reduction turned on.

If I've configured the scene incorrectly that would be good to know but it seems to be set up as required as far as I can tell.



Very strange. Your test case works fine for me on both WM 2.2 and 2.3 Beta-1, by simply setting a filename and building the world you provided. The default maximum is a fairly large number of triangles; try setting to something very restrictive like 1k and see if you still notice the lack of reduction?
-- Stephen Schmitt
- Creator of World Machine

Eric Cosky

Definitely strange; perhaps I'm just doing something wrong but it seems pretty straightforward.. I've tried a couple times since this morning and haven't yet seen any triangle reduction occur. I'll take another look at it sometime soon.

Eric Cosky

July 17, 2011, 04:38:40 pm #3 Last Edit: July 17, 2011, 11:05:04 pm by Eric Cosky
I figured it out, sort of. It is in fact reducing - I misinterpreted the results. I had put in 256, thinking that "Target kTri count" meant "target triangle count". When the file had hundreds of thousands of triangles I assumed it wasn't working because I expected a small file with around 256 triangles.  It turns it "Target kTri count" seems likely to mean something like "Mesh reduction factor" as opposed to "how many triangles are we trying to produce". Or maybe it's edge subdivision? The help page for the mesh output doesn't even mention the reduction feature (incidentally it also doesn't mention the mesh output device's mask input, and I have no idea what it is used for).

So, can you perhaps explain what this target count really controls, how the reduction algorithm works in general terms, as well as what the mesh output device mask input is intended to be used for?

Thanks for any info


Hi Eric,

it is a simple reduce-resolution and triangulate option -- it is simply scaled to thousand-of-triangles rather than triangles as the number of exported triangles is usually a large number.

Also, the mask input allows you to only meshify certain parts of the terrain -- any value above 0.5 indicates that that source pixel in the primary input should be triangulated. Thus providing, for example, a spherical shape from the radial gradient generator would create a circular terrain area, or a layout spline path would allow you to export only certain areas of geometry.
-- Stephen Schmitt
- Creator of World Machine

Quick Reply

With Quick-Reply you can write a post when viewing a topic without loading a new page. You can still use bulletin board code and smileys as you would in a normal post.

Warning: this topic has not been posted in for at least 120 days.
Unless you're sure you want to reply, please consider starting a new topic.

Note: this post will not display until it's been approved by a moderator.

Please leave this box empty:
Type the letters shown in the picture
Listen to the letters / Request another image

Type the letters shown in the picture:

Shortcuts: ALT+S save/post or ALT+P preview