Wrong imposter normals.
by Duion · in Torque 3D Beginner · 03/07/2013 (2:08 pm) · 7 replies
I have the strong suspicion that the imposter normals are wrong way.
But pictures are better to explain:
and I do not know exactly how the imposter normals work, but I manually inverted them and the result was this:
also you can see the missing poles, by the way, I just want some affirmation and if so, I will report as a bug.
From my research I found, that in directX the normal maps have the y-axis inverted, so when you generate normal maps for directX games you have to invert the y-axis, this may be the cause.
But pictures are better to explain:
and I do not know exactly how the imposter normals work, but I manually inverted them and the result was this:
also you can see the missing poles, by the way, I just want some affirmation and if so, I will report as a bug.
From my research I found, that in directX the normal maps have the y-axis inverted, so when you generate normal maps for directX games you have to invert the y-axis, this may be the cause.
About the author
http://www.duion.com - Human Paradigm Specialist
#2
03/17/2013 (7:35 am)
Hm but now the normals on the shape are a little bit backwards and thats not nice in some cases, a button for flipping the imposter normals would be considerable. 
#3
Did you try to rebuild the imposters by deleting the imposter files?
04/10/2013 (9:47 pm)
Never had incorrect normals for imposters generated by the shape editor . However, I did encounter 'wrong' normals for billboards; that's when I didn't make the pivot of the plane object match with the world (flipped Y) and used the billboard function in the shape editor.Did you try to rebuild the imposters by deleting the imposter files?
#4
The normals define where the shape receives light, so the problem is, that sometimes on side gets a lot more light than the other, or the lighted side is dark and the dark side is bright.
04/11/2013 (2:59 am)
Whats the difference between imposters and billboards? At the moment I just changed the color of the imposter files with an image editing program, until they look ok.The normals define where the shape receives light, so the problem is, that sometimes on side gets a lot more light than the other, or the lighted side is dark and the dark side is bright.
#5
When the shape draws a lot of shadows then the imposters can turn out a bit dark. If you need to check if it's a normal map issue, fill it up with a solid color: RBG 128 128 255 (flat)
Just a tip; Imposters are generated by the editor. If you re-import you shape file (DAE or DTS), the imposters can be overwritten. If you edit those, make sure you keep a copy somewhere :)
If the imposter function doesn't give the result you want, you might want to try to create a billboard manually (see the primer). However, that could have an effect on your fps, I think.
04/11/2013 (5:14 am)
The differences between billboards and imposters can be seen here: Torque Art PrimerWhen the shape draws a lot of shadows then the imposters can turn out a bit dark. If you need to check if it's a normal map issue, fill it up with a solid color: RBG 128 128 255 (flat)
Just a tip; Imposters are generated by the editor. If you re-import you shape file (DAE or DTS), the imposters can be overwritten. If you edit those, make sure you keep a copy somewhere :)
If the imposter function doesn't give the result you want, you might want to try to create a billboard manually (see the primer). However, that could have an effect on your fps, I think.
#6
Mostly I get this effect with pine like trees, where the meshes point more upward.
04/11/2013 (5:47 am)
It is because of the normals, as you can see in the pictures. First two is autogenerated from the shape editor and second is these autogenerated but manually inverted the colors.Mostly I get this effect with pine like trees, where the meshes point more upward.
#7
Here I made a picture to show you the default imposter with its result and next to it a tree with manually inverted colors of imposters.
I noticed you need to invert to color to make them correct, so there may be some inverted axis somehere, either in the model or in the code.
Anyone get any ideas where this comes from or how to solve that? Maybe this is something to be fixed, since a lot of people will have wrong imposters, if this is an error in the engine.
At the moment I inverted the colors of all imposter files by hand, but this cannot be a long term solution.
06/11/2013 (5:58 pm)
Noticed the thing again while editing a few old models:Here I made a picture to show you the default imposter with its result and next to it a tree with manually inverted colors of imposters.
I noticed you need to invert to color to make them correct, so there may be some inverted axis somehere, either in the model or in the code.
Anyone get any ideas where this comes from or how to solve that? Maybe this is something to be fixed, since a lot of people will have wrong imposters, if this is an error in the engine.
At the moment I inverted the colors of all imposter files by hand, but this cannot be a long term solution.
Duion