Imagination PowerVR SDK Blog

PVRShaman black model

pvrshaman

#1

I am new the the powerVR tools. But I have managed to export my POD file out of Maya. Write a mini-rendering engine in xCode that runs on my iPad app. The pod file comes up fine. my PFX effect file works fine in my app.





The only thing that is frustrating is PVRShaman. I can bring up my POD model in Shaman. My PFX effect file builds with no errors. But it the model is completely black no matter what I do. Very frustrating.





I am running PVRShaman Version 1.9 on a Mac OS.





Would anyone out there have some ideas what I am doing wrong here?


Thanks in advance.


#2

A clarification…





The POD model comes up in Shaman. The Effect file compiles in Shaman. But in Shaman, the model is just black as though the POD model and Effect file have not “hooked up” yet.


#3

Found the solution.





The problem was with my interpretation of vertex color between my app and Shaman. Shaman normalizes the RGBA vertex color stream from the 0-255 range to the 0.0 to 1.0 range.





In my app, I wasn’t normalizing the vertex color stream. Instead, I was dividing the raw 0-255 data by 255.0 in the vertex program. Thus my vertex color was coming across black.



#4

I’m glad you worked this out and thank you for posting the solution for others.

Texture sampler colour values in GLSL ES will always be returned as floats between 0 and 1.0 (not just in PVRShaman).