Move headlight pos/dir computation from mjr_render to mjv_updateScene.

PiperOrigin-RevId: 586630110
Change-Id: Ia44ea944016ccfe081682375cdb975342695d826

src/engine/engine_vis_state.c

@@ -241,12 +241,12 @@ int mjv_updateSceneFromState(const mjvSceneState* scnstate, const mjvOption* opt
   // add all categories
   mjv_addGeoms(&m, &d, opt, pert, catmask, scn);
 
-  // add lights
-  mjv_makeLights(&m, &d, scn);
-
   // update camera
   mjv_updateCamera(&m, &d, cam, scn);
 
+  // add lights
+  mjv_makeLights(&m, &d, scn);
+
   // update flexes
   if (opt->flags[mjVIS_FLEXVERT] || opt->flags[mjVIS_FLEXEDGE] ||
       opt->flags[mjVIS_FLEXFACE] || opt->flags[mjVIS_FLEXSKIN]) {

src/engine/engine_vis_visualize.c

@@ -30,6 +30,7 @@
 #include "engine/engine_util_misc.h"
 #include "engine/engine_util_spatial.h"
 #include "engine/engine_vis_init.h"
+#include "engine/engine_vis_interact.h"
 
 //----------------------------- utility functions and macros ---------------------------------------
 
@@ -2087,6 +2088,12 @@ void mjv_makeLights(const mjModel* m, mjData* d, mjvScene* scn) {
     thislight->directional = 1;
     thislight->castshadow = 0;
 
+    // compute head position and gaze direction in model space
+    mjtNum hpos[3], hfwd[3];
+    mjv_cameraInModel(hpos, hfwd, NULL, scn);
+    mju_n2f(thislight->pos, hpos, 3);
+    mju_n2f(thislight->dir, hfwd, 3);
+
     // copy colors
     f2f(thislight->ambient, m->vis.headlight.ambient, 3);
     f2f(thislight->diffuse, m->vis.headlight.diffuse, 3);
@@ -2723,12 +2730,12 @@ void mjv_updateScene(const mjModel* m, mjData* d, const mjvOption* opt,
   // add all categories
   mjv_addGeoms(m, d, opt, pert, catmask, scn);
 
-  // add lights
-  mjv_makeLights(m, d, scn);
-
   // update camera
   mjv_updateCamera(m, d, cam, scn);
 
+  // add lights
+  mjv_makeLights(m, d, scn);
+
   // update flexes
   if (opt->flags[mjVIS_FLEXVERT] || opt->flags[mjVIS_FLEXEDGE] ||
       opt->flags[mjVIS_FLEXFACE] || opt->flags[mjVIS_FLEXSKIN]) {

src/render/render_gl3.c

@@ -613,7 +613,7 @@ static void initGL3(const mjvScene* scn, const mjrContext* con) {
 
 
 // init lights
-static void initLights(mjvScene* scn, const float* headpos, const float* gazedir) {
+static void initLights(mjvScene* scn) {
   // create some ambient light if no ligths are present
   float global = scn->nlight ? 0 : 0.3f;
   float rgba_global[4] = {global, global, global, 1};
@@ -623,14 +623,6 @@ static void initLights(mjvScene* scn, const float* headpos, const float* gazedir
   glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, 0);
   glLightModeli(GL_LIGHT_MODEL_LOCAL_VIEWER, 1);
 
-  // headlight: set pos and dir
-  if (scn->lights[0].headlight) {
-    for (int i=0; i < 3; i++) {
-      scn->lights[0].pos[i] = headpos[i];
-      scn->lights[0].dir[i] = gazedir[i];
-    }
-  }
-
   // set light properties
   for (int i=0; i < scn->nlight; i++) {
     // colors
@@ -762,8 +754,8 @@ void mjr_render(mjrRect viewport, mjvScene* scn, const mjrContext* con) {
   int stereo, nt, ngeom = scn->ngeom, nlight = mjMIN(mjMAXLIGHT, scn->nlight);
   unsigned int drawbuffer;
   mjvGLCamera cam;
-  mjtNum hpos[3], hfwd[3];
-  float temp[4], headpos[3], forward[3], skyboxdst;
+  mjtNum hpos[3];
+  float temp[4], headpos[3], skyboxdst;
   float camProject[16], camView[16], lightProject[16], lightView[16];
   double clipplane[4];
   float biasMatrix[16] = {
@@ -827,13 +819,12 @@ void mjr_render(mjrRect viewport, mjvScene* scn, const mjrContext* con) {
     drawbuffer = GL_COLOR_ATTACHMENT0;
   }
 
-  // compute head position and gaze direction in model space
-  mjv_cameraInModel(hpos, hfwd, NULL, scn);
-  mju_n2f(headpos, hpos, 3);
-  mju_n2f(forward, hfwd, 3);
-
   // init lights
-  initLights(scn, headpos, forward);
+  initLights(scn);
+
+  // compute head position in model space
+  mjv_cameraInModel(hpos, NULL, NULL, scn);
+  mju_n2f(headpos, hpos, 3);
 
   // make list of transparent geoms
   nt = 0;