I’m trying to render some designs for an animation I have coming up and my mesh keeps having ‘cracks’ in it when I render it. It’s really some simple modeling with edge split and subsurf mods applied to it in that order and I’ve tried different combinations of mods (on and off) - recalculating and flipping normals and nothing seems to be working. I tried using creases to get my hard lines instead of the edge split mod, I’ve tried just adding extra loop cuts, I’ve tried using both a ngon and a triangle fan of the internal cylinder… nothing helps
Does anyone have any thoughts on why this is happening?
Is this Cycles render ? Is it done using Orthogonal camera? What is the size in BU of object in concern ?
It is always better to have quads; have face ring and combine small middle triangle fan into diamonds F joining pairs of triangles.
Just a quick follow up - if I use a regular plane (4 points) there are no problems.
Also, these cracks don’t appear when I use Rendered Viewport Shading, just when I actually render the scene.
Hopefully that’s more helpful information to figure this out
Thank you
it happens on any object I put there other than a 4point plane. There is no UV mapping going on, just a glossy shader right now. Could this be a bug in 2.71? My camera is also really close to the image, could that be an issue because my client has already approved the look of this shot and it would be hard to replicate if I moved the camera. I havent tried removing doubles yet but I’ll try that and an older version of blender in the morning- Also, it doesn’t happen if I move everything over to BI - just looks like a cycles issue
Thanks so much I really appreciate everyones help
Yes, I think it depends on the Camera in some way, in fact the referring of eppo to an orthogonal camera have much sense to me.
Try and move the camera backward and increase the focal length.
Seems like Camera being too close issue: here is a similar render - difference is size. If i read correct yours is 0.152 x 0.152 BU ?
You can see comparison on image.
To eliminate cracks you could size up all scene and move Camera on Local Z axis while you get the same region in camera view; set focal length to around 50 ~ 70, this will make view look closer to ortho (which you had before due to camera being close to the objects).
Edit: btw, it looks like you have some geometry issues -
it looks like scaling up the whole scene works to get rid of the cracks, but WOW! That’s really annoying because now I really need to re-animate my whole scene because the last frame of this animation is supposed to be a match cut onto the next scene. This needs to be fixed in cycles - my other alternative was to switch it over to BI and render that out.
Thanks for the help everyone
Oh and thats a reflection issue, not a geometry issue - thanks though
just a quick update - didn’t quite look right with the larger scale and the longer lens on the camera. the change in FoV just didn’t look right so I ended up just retexturing in BI… good times
Hey, I am also having this issue now. I did some experiments and i found out that cracks are more if the object is away from the center of the blender default scene (global X, Y, Z = 0 point) (center of the grid floor). As i moved the object farther away from the center, cracks incresed. And as i brought the object closer to the center, cracks decreased. I can’t surely say whether they disapeared completely when the object was exactly in the center, but it is definitely better.
Please, try it out, and say what happenes with you. And please also tell me if anyone has got other solution as well.
ok. I rendered my model two times. once away from center and second time close to the central position. sample is kept 1000 for both the rendering and relative position of the light and camera were also kept constant while moving the object close to the center. here are both the images.
this is the image that was rendered while object was away from the center.
and this is the image after moving the object (and light and camera as well) close to the center.
if you zoom in, you can clearly see that the cracks are less when object is close to the central position.
so the issue of cracks is solved for me for now. (in fact, now my problem is the strange black shadows near the edge of all holes in the image. they are there even in the image where object is closer to the central position. but that is the topic for different thread.)
please tell if anyone know the actual reason behind the cracks that decreases on moving the object close to the central position.
and also tell me if same thing happens for you also. so that I can decide whether its issue with blender itself or my modeling is the issue.
The camera is not the problem here.
As pointed out in the posts before, you have geometry issues. The cracks looks to me a giant ngon (circle) with subsurf applied.
Here an example:
With subsurf becomes:
As you can see the cracks ( visibles in other parts of the mesh too ) are a result of bad topology.
Try deleting all hidden vertex first, then try to create quads or tris out of your ngons, or at least try adding a few loops to support them.
P.S. The attachments in your last post are broken, try uploading them again.
