wierd render issues--help!
Hi Everybody,
I'm working on a revolver design. Modeled in Maya LT, baked with Turtle and then laid down some base textures using nDo and dDo. Attached screen01 shows my progress so far. While it looks ok from a distance, when zoomed in it seems to have strange shading errors, especially below the hammer and above the safety in the screenshot (but it's really an issue all over) as you'll see in the attached screen02. Screen03 shows the same with wireframe, so you can see that the problems seem to follow the tesselation of the lowpoly.
Same thing happens in the Maya LT viewport. I can minimize it in Maya LT by adjusting sliders for Tangent Space, but it doesn't help once I've exported the model, either .obj or .fbx. My normal maps look perfectly fine and smooth, so I don't think it's a normal map problem. Or maybe the normal map should be fixing this, but it isn't, I dunno.
Anyone have ideas on how to fix this?
thanks,
jer
PS: separately, from watching videos online I understand that a previous version of dDo had something called the Automation Hub and that from there one could load maps and select a button called something like "minimize seams" with the AO. I can't find this feature with the most recent version and have to turn my AO down to zero in dDo. If anyone knows how to remedy this, it would be much appreciated.
I'm working on a revolver design. Modeled in Maya LT, baked with Turtle and then laid down some base textures using nDo and dDo. Attached screen01 shows my progress so far. While it looks ok from a distance, when zoomed in it seems to have strange shading errors, especially below the hammer and above the safety in the screenshot (but it's really an issue all over) as you'll see in the attached screen02. Screen03 shows the same with wireframe, so you can see that the problems seem to follow the tesselation of the lowpoly.
Same thing happens in the Maya LT viewport. I can minimize it in Maya LT by adjusting sliders for Tangent Space, but it doesn't help once I've exported the model, either .obj or .fbx. My normal maps look perfectly fine and smooth, so I don't think it's a normal map problem. Or maybe the normal map should be fixing this, but it isn't, I dunno.
Anyone have ideas on how to fix this?
thanks,
jer
PS: separately, from watching videos online I understand that a previous version of dDo had something called the Automation Hub and that from there one could load maps and select a button called something like "minimize seams" with the AO. I can't find this feature with the most recent version and have to turn my AO down to zero in dDo. If anyone knows how to remedy this, it would be much appreciated.
Replies
The first image is taken from Maya LT 2015. It shows a high poly and low poly cylinder. A normal map has been applied to the low poly, and while its still fairly ugly, the length of the cylinder is in fact smooth.
The second image is the same low poly cylinder that's been exported as an .obj and taken into dDo, with the same normal map applied. You'll see it has prominent-looking edges running the length of the cylinder.
What the hell am I doing wrong?
These edges can show up in Maya, but are fixed by using Normals > Soften Edge.
If anyone has any ideas, I'd greatly appreciate it.
thanks,
jer
3ds Max does same to my model and textures - guess nobody knows
http://www.polycount.com/forum/showthread.php?t=134875
The difference is that for this cylinder, rather than averaging normals for the whole mesh like before, there are hard edges at the caps. It seems to me like the issue has something to do with my UV texture seams. Basically, anywhere I have a texture seam, I must put a hard edge, otherwise the exported model shows the edges like in the first instance I posted.
Having read through the entire normal mapping and hard edges stickies, I'm pretty sure folks have written that a texture seam is necessary along a hard edge, but that a hard edge is optional (and "free") along a texture seam.
It seems in my case, using Maya LT exporting to dDo, the hard edge is not optional--it's required.
Now if anyone could explain why this is, or even better, how fix it, that would be lovely.
cheers,
jer
http://wiki.polycount.com/NormalMap/
and check your triples, and turn them so they all flow. Remember that the harsher your tri turn is the less pixels its getting as the corner of the tri squeezes in. So avoid them if possible.
cheers
So I've done more tests and I think that what is going on is an exporter issue. When exporting to .fbx, if I leave the option to "split per-vertex normals" unchecked, then I don't seem to get the same problem with edges showing up on the model. I've imported it into UDK and fortunately that seems good too.
Attached you'll see the results of some tests I done that involve taking the pistol grip I've been working on in Maya LT and exporting it, then re-importing it to see the results. The exported model was triangulated in Maya LT and all edges softened before export. It was exported with the following options, then re-imported:
1. FBX, split per-vertex normals unchecked
2. OBJ, all options checked
3. OBJ, all options minus smoothing
4. OBJ, all options minus normals
5. OBJ, all options minus point groups
6. OBJ, all options minus materials
7. OBJ, all options minus groups
8. OBJ, all options unchecked except normals
What you'll see in the attached image is that all but #1 and #4 from the right seem to have the problem with prominent edges showing up with the same normal map is applied. Unfortunately, when #4 is imported to dDo (only accepts .obj, hoping for .fbx in the new suite), dDo gives me all hard edges in the previewer.
At the end of the day it will be fine because it doesn't show up in UDK, but it's annoying to see it in dDo. Other people don't seem to be having this problem, so I'm wondering if there is something I should be doing in Maya LT to prepare my model for export to .obj, or what?
http://www.covertengine.com