Author Topic: Rendered in black with multiple texture files (jpg + png)  (Read 572 times)

Offline yjoo9317

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Rendered in black with multiple texture files (jpg + png)
« on: October 31, 2018, 09:44:24 pm »
Hi,

my model mtl file is pointing to 2 texture files for body (.jpg) and shadow (.png) respectively.
I noticed the model is rendered in almost black. (with a little red-ish area)
If I exclude png file then it renders the model fine but obviously shadow area is also rendered with body texture.
Am I missing something here?

note: when adding png texture, I also turned on "useAlpha" parameter as well.
        Also loading the model from serial file to speed up.

Offline EgonOlsen

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #1 on: October 31, 2018, 11:07:35 pm »
How are you assigning the textures?

Offline yjoo9317

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #2 on: November 01, 2018, 10:19:24 pm »
<mtl>
newmtl Body_White
Ka 1.000000 1.000000 1.000000
illum 1
map_Ka body.jpg

newmtl FLOOR
Kd 0.800000 0.800000 0.800000
illum 1
map_Kd floor.png
map_d floor.png


//Add texture to TextureManager
TextureManager.getInstance().addTexture(name1, new Texture(tfis1)); // for body tfis1 is FileInputStream to .jpg file
TextureManager.getInstance().addTexture(name2, new Texture(tfis2, true)); // for floor tfis2 is FileInputStream to .png file. tried both with or without alpha. neither work.

//and then Set Texture
model.setTexture(name1); //  for body.jpg
model.setTexture(name2);  // for floor.png

If I exclude name2 texture, then at least it can render the body fine.


Offline EgonOlsen

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #3 on: November 02, 2018, 12:22:43 pm »
It doesn't work that way. For assigning multiple textures to one mesh, you have to rely on the auto-assignment. setTexture(...) sets the texture for the whole mesh at once. What you actually want to do, is to remove the setTexture()-calls and make sure that name1 and name2 in the addTexture()-calls match the names from the mtl-file. In case of doubt, have a look at the log output when loading the model for the exact names.

Offline yjoo9317

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #4 on: November 02, 2018, 07:51:02 pm »
Thanks for the reply.

I removed setTexture calls and leave it doing auto-set.

I noticed that each texture was applied to the area where it was supposed to be.

But still floor texture (png file) is rendered in black..
10% of the png texture is shadow and the rest area is transparent.

That 10% (shadow) was rendered in red and the transparent area is rendered in black.
Any clue on that?
png file with transparency would cause the problem?

The reason why I am saying this,
If I switch png to jpg file instead, then it renders it at least.
But to draw the proper alpha channel, it needs to use a png file still.

Thanks.

Offline EgonOlsen

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #5 on: November 03, 2018, 12:53:27 pm »
Not sure if that's your issue here, but you can't have transparent parts in objects that are actually opaque. What you are seeing there might be the actual color of the png texture without the alpha channel. Can you split your model into two, where one contains the opaque parts and one the transparent one?

Offline yjoo9317

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #6 on: November 05, 2018, 05:37:28 pm »
I attached png file.
The floor is a simple plain with just 4 vertices.
I've also confirmed that it renders OK with .jpg file (converted from the exact .png file).

The following is from obj file.
---------------------------------------------
o Plane.1
v -10 0 10
v 10 0 10
v -10 0 -10
v 10 0 -10
# 4 vertices

vt 0.00000 0.00000
vt 0.00000 1.00000
vt 1.00000 1.00000
vt 1.00000 0.00000
# 4 texture coordinates

vn 0 1 -0
# 1 vertex normals

usemtl FLOOR
f 1805/2771/1549 1807/2770/1549 1806/2769/1549 1804/2768/1549
# 1 facets
--------------------------------------------------------------------------------------

Note.
I'd tried to upload png file but there was a size limit (up to 64k), so I had to resize but the color space is intact.
Let me know if you notice something else.

Offline EgonOlsen

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #7 on: November 05, 2018, 05:47:06 pm »
...and the floor is a seperate file or is it part of the complete model? Do you have a screenshot of the red rendering?

Offline yjoo9317

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Re: Rendered in black with multiple texture files (jpg + png)
« Reply #8 on: November 07, 2018, 04:39:15 pm »
Floor plane is in the same obj file.

I will upload screen shot soon.. It won't be full view but at least it will show what is like.