View Full Version : Missing Polys in Animation

11 November 2003, 06:23 PM
I am having a problem with missing polys in my renders. I think that the problem is related to textures and shadowing calculations because the problem is most pronounced in the shadow areas of the model. At first I thought it was a problem with flipped polys but that was not it, so I checked for smoothing errors by increasing the density of the mesh, but still the problem persists. One thing that I did notice was that if I simplify the use of procedural textures the problem decreases (but not entirely) which leads me to believe it is a memory problem. I have a gig of ram and the model is fairly light which I believe should be more then enough for such a simple model.

Does anyone have any suggestions on what the problem might be?

11 November 2003, 06:44 PM
Might it be caused by non-planar polygons? Show us a screen shot if you can.

11 November 2003, 08:03 PM
Hi Finkster,

Thatís what I thought too, so I tripled all non-planer polys and it had no effect. I can post a screen shot when I get home to hopefully make it little clearer. This is actually the third animation that I have had this problem with. At least with the other animations I was able to screen the problem, this time around I would like to know what is causing it so I can avoid the problem once and for all.

W Wade
11 November 2003, 08:36 PM
Are you using clip maps on the object in question?

11 November 2003, 08:48 PM
Yes I am using a combination of both procedural and image maps. Here is the object I am having a problem with (the rock the character is standing on). It is a fairly simple texture.

Actually you can see the problem on the rock under the chracter in the shadows, there are missing polygons. When I look at the mesh there isnít even any polygons or groups of polygons that match that shape in that area.

11 November 2003, 09:55 PM me those look like shadows....How about a wireframe:shrug:

11 November 2003, 01:20 AM
Well I checked to flipped polys again and nothing, this is really getting frustrating. Iím pretty sure now that it is a shadowing error with the area lights. I turned the quality up to 5 (is this as far as it will go with area lights?)

Here is the rock again in modeler smoothed:


Rendered with missing polygons:


11 November 2003, 01:27 AM
can you post the model?

it kinda looks like you might have over lapping polys or doubled or something but you said you flipped them

did you try deleteing that area and see if it is doubles or not?

11 November 2003, 03:59 AM
You are welcome to take a look. But be warned, when the subpatch is turned off itís really a mess. It probably is the model.

Here is the rock model. (

11 November 2003, 07:25 AM
Sorry, haven't been able to see any missing polygons when looking at your file. If the polygons were really missing, you should be able to see right through the object.
Try rendering the object with very high global ambience, then you can be test if it is just very strong shadowing or missing polygons.
I have a hunch that it may have something to do with the large number of intersecting surfaces - maybe that doesn't play well with area lights.
Have you tried making your object double sided? As a last resort you could try remodelling the shape, avoiding overlapping polygons - model in polygon mode to make sure.

Good luck!

11 November 2003, 03:11 PM
from the wires i see it seems that you have overlapped polys, not missing ones. this can generate different kinda probs. its better to have a more clean wire for the same shape result. however, maybe freezing your object and reduce polys before saving, could do the job.

11 November 2003, 03:18 PM
Finkster Thanks!

You were right about the intersecting surfaces. I went back in and pulled a bunch of points and presto, problem fixed. Thanks to everyone for taking the time to help.

11 November 2003, 03:26 PM
I forgot about the freeze command, I tried that and it was much easier to fix the mesh. Thanks again guys. Iím glad to find out what I am doing wrong.

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