fix spherical harmonics baker format fallback and catch NaN early

Author: riccardobl

jme3-core/src/main/java/com/jme3/environment/baker/IBLGLEnvBakerLight.java

@@ -104,9 +104,11 @@ public void bakeSphericalHarmonicsCoefficients() {
         float remapMaxValue = 0;
         Format format = Format.RGBA32F;
         if (!renderManager.getRenderer().getCaps().contains(Caps.FloatColorBufferRGBA)) {
-            LOG.warning("Float textures not supported, using RGB8 instead. This may cause accuracy issues.");
-            format = renderManager.getRenderer().getBestColorTargetFormat(true, true, false, false);
-            remapMaxValue = 0.05f;
+            format = renderManager.getRenderer().getBestColorTargetFormat(true, true, true, false);
+            if(!format.isFloatingPont()){
+                LOG.warning("Float textures not supported, using RGB8 instead. This may cause accuracy issues.");
+                remapMaxValue = 0.05f;
+            }
         }
 
         if (remapMaxValue > 0) {
@@ -170,6 +172,7 @@ else if (weightAccum != c.a) {
         for (int i = 0; i < NUM_SH_COEFFICIENT; ++i) {
             if (remapMaxValue > 0) shCoef[i].divideLocal(remapMaxValue);
             shCoef[i].multLocal(4.0f * FastMath.PI / weightAccum);
+            assert Vector3f.isValidVector(shCoef[i]);
         }
         EnvMapUtils.prepareShCoefs(shCoef);
         img.dispose();