Hello,

I have simple textured and skinned surface.
I keep getting black stains and spots in the surface especially in the angled or slanted area whenever i rendered.
I did everything by adjusting light and shadow without any success.
Can any one help me Please.
I am using Mac and Mantra.

Steve

Ummm … a picture would be nice to see. Also a bit more information about type of shader, etc. Maybe a hipfile? Kinda tough to diagnose without info

I guess something wrong with mantra.
because the more i use the worse it is. meaning the more black staiens and spots. it was working better a month ago.
I use just general shader with some painting using photoshop.
my obj is jst a skinned animated surface with painted texture.
Anyway, it looks dirty with black stains and spots.
And noticed the rendering speed i s getting really slower.
in Mantra, i checked Enable Depth of field and allow motion blur.
I also cranked to 7 in Pixel Sample in sampling of the mantra

Can you help me please.
Also, frequently, my mantra can not render so i have to restart the houdini and it's working.

Again, without an image &/or hipfile, it's really hard to give you a solution. However, if I was to guess …

If you have deforming surface, check to see if you have vertex normals on the geometry. If you do, delete them using an attribute SOP.

In terms of mantra slowness, enabling depth of field will increase your rendering times.

Thank you very much.

i did not see any difference even with depth of field. But, i will try that.
All of a sudden my rendering speed is very slow, i believe, after i rendered my obj with file node to save it to bgeo.
Even using imported bgeo format obj, i still have very slow rendering all of a sudden but a little better in rendering bgeo obj.

About the stain in the rendered obj especially in the shaded area.
I noticed that it is from only one lighting source out of three lights.
I wonder why. the stain is visible on the angled or slanted surface.

Can you help me further ?

Steve

can it be your shadows? try turning them of
it they are causing it, you'll need to adjust Shadow Bias according to your scene scale

you are right.

I just figure it out just by changing the direction of the other ilght.

Thank you anyway. I've wasted many days to figure it out this simple cause.

Steve

After i tried many times, i realized raytrace shadow is better than depth map.
I am still having some shadow problems with depth map. i still have some stained surface and shadow after rendering. I am just rendering a textured, skined flat surface.
whenever i use raytrace shadow, I can not render all the frames. Wonder why. some frames are missing showing “as bad image”
Can any one help me please.
I've been wasting many days just in lighting, shadowing, and rendering for just one simple 24 frames sequence animation.

Steve.

Without an example file we can only guess what's wrong. I don't have any guesses right now.